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Biological Farming & Gardening

A newer science that’s not tied to petroleum profits is emerging to challenge the industrial approach to agriculture and gardening. Enormously powerful, politically connected giants like Monsanto, Bayer, and Dupont will continue to make money, but after 60 years of dominance, the “Better Living Through Chemistry” model can no longer hide its fatal flaws. Mountains of evidence now point to the downside of chemical agriculture: poisoning the earth, driving global climate change, causing major health problems, killing pollinators, destroying the life of the soil. The good news is that a more long-range, wholistic view called Biological Agriculture and Gardening is starting to take its place.

This “new” method is based on an entirely different paradigm or model of plant culture. Instead of the bellicose mentality that birthed the pesticide-fungicide-herbicide and chemical fertilizer approach, the biological approach taps the same cooperative relationships that Nature herself has long employed successfully for survival and sustainability. Instead of seeing bacteria as germs, fungi as diseases, and insects and weeds as pests, the biological model sees Nature as brilliantly creative and diverse, and basically good. The scientific truth is that few insects, bacteria and fungi are harmful; most are beneficial or essential to plant development, plant health, and subsequently for human health.[Read More]

Narcissus poeticus – Double Albo Pleno Odorata

Double Poets Daffodil

Bulb. Z3. 16-18” tall. Blooms late spring. Compost-improved soil. Heirloom.

Full, ruffled, snowy-white blooms are a gorgeous, bright beacon in your spring garden. Highly fragrant, so be sure to place them near paths and patios where you can enjoy them. Blooms are most prolific in cool springs. Deer and rabbit resistant. Lovely combined with columbine, Icelandic poppies and bleeding hearts.

Non-Toxic Weed and Pest Control

Non-toxic Herbicides

Summer is a successful time to kill weeds, either by mechanical weeding or with herbicides. But toxic herbicides, like Roundup are not solutions we recommend. Roundup in particular was once believed to be quite safe, but now is shown to be harmful to soil life including nitrogen-fixing bacteria, amphibians and is a probable human carcinogen. Roundup formulations can be up to 400 times more toxic than the active ingredient, glyphosate.

At Harlequin’s Gardens, we only sell non-toxic products, but not all non-toxic products are actually effective. Four years ago we tested five non-toxic herbicides and found only two to be really effective: 20% Vinegar and Avenger.

20% Vinegar is 20% acetic acid. It is a non-selective organic acid that quickly kills many weeds, then quickly biodegrades. Repeated use can acidify the soil which is usually a benefit in our alkaline soil. Be careful not to spray desirable plants, and be careful to protect your eyes, especially on windy days. It is most effective on small plants. Repeated applications may be necessary on perennial weeds.

Avenger is a citrus oil weed killer that we found to be equally effective as the vinegar. It is certified organic and is biodegradable. Avenger is non-selective so care must be taken to keep spray off desirable plants. It comes in a ready-to-use (RTU) formula and in a concentrate which may be mixed stronger for tougher, perennial weeds. Like vinegar, it is most effective on small plants, and is best sprayed during hot weather in direct sunlight.

In order to “control” bindweed and other weeds with extensive root systems, don’t let new growth get longer than 2″ or the weed will revive.

 

BLISTER BEETLE: We have been hearing reports of Blister Beetle attacking clematis. This is a light grey, long beetle that can defoliate a clematis vine in 2 or 3 days. We have found that an organic product called Veggie Pharm actually kills this beetle. It must be sprayed directly on the beetle. (Don’t try to pick up a Blister Beetle; they can raise a blister)

 

Tree Wrap: We recently saw a big buck with his antlers in the velvet stage. This the time of year deer cause the most damage, when bucks rub their itchy antlers on smooth, usually young tree trunk, tearing the bark. Sometimes a young tree can be girdled in one night. We carry a very good spiral plastic tree wrap that protects trees from deer, rabbits, sun scald in winter. It is superior to paper wraps because it lets air circulate so moisture does not decay the bark. It can be left on in the summer and it expands as the tree grows. Once the bark is older and tougher, it will no longer need protection.

Curl-Leaf Mt. Mahogany

Curl-leaf Mt. Mahogany (Cercocarpus ledifolius)

This tall shrub or short tree is a beautiful broadleaf evergreen that is native to Colorado and much of the west up to 9000’. It’s narrow, curled leaves are an adaptation to reduce exposure to drying sun and wind; consequently it is very drought resistant, needing no irrigation after being established.The leaves are also thick, leathery, resinous and dark green above and pale below. Flowers are mostly inconspicuous and the fruit is only 1/4” long with a 2”-3” long silky tail. In dry weather these tails twist like a cork screw and with a little wind can be carried a good distance and then they will screw the seed right into the soil.[Read More]

2018 Taste of Tomato Results

This year’s Taste of Tomato was a blast! We love the new location at Growing Gardens’ Barn, with its’ beautiful view of the Flatirons, easy access, and wonderful staff. The tasting featured 44 different varieties of tomatoes, with Aunt Ruby’s German Green winning the greatest number of votes. Participants brought in some wonderful new varieties this year, including Brad’s Atomic Grape, Thornburn’s Terracotta, and Indigo Cherry. Look for the most popular varieties from this year and previous years when you come to buy your organic tomato starts next spring at Harlequin’s Gardens. Every year we grow 80+ great varieties for all kinds of uses and growing conditions![Read More]

Harvest Guidelines for Summer Crops

Here are a few harvest guidelines for summer crops: 

Eggplants should be picked while they are still firm and glossy.  Once their skins have become dull, they will be softer and have dark seeds, which can spoil the flavor. Eggplants don’t keep long, so use them soon after harvest.

Bell peppers and sweet frying peppers are sweetest when allowed to ripen fully to their mature color, yellow, orange, red, purple or mahogany.  Bell peppers are often picked green, but their flavor will be a lot more pungent and they may be more challenging to digest.

Some of the hot peppers are traditionally enjoyed green – poblano, mulatto, jalapeno, Anaheim-type, while most of the rest are allowed to ripen to red (cherry, habanero, cayenne, lanterna, any chile dried for a ristra, etc.) orange (Bulgarian Carrot), or dark brown (Pasilla).[Read More]

A Xeriscape Harvest

For most people, harvest time brings to mind a cornucopia of veggies and fruits. For me, the end of this 2009 growing season has been a fruition of over 20 years of cultivating a xeriscape where most of the trees and shrubs have been watered 5 times a year or less. These self-imposed watering restrictions have demonstrated which plants can survive and thrive under serious water shortages. I have done this both to encourage water conservation in Colorado and to demonstrate that a dry western landscape can be beautiful.

The reason why 2009 feels like a harvest year is because many of my woody plants are now mature and because with all the rain we’ve been getting, my xeriscape has never looked better at the end of summer.[Read More]

Tulipa ‘Paul Scherer’ Triumph Midseason Tulip – NEW AGAIN!

NEW for 2019!
The darkest Triumph tulip, dramatic purple-black with a straight-sided shape. Earlier than ‘Queen of Night’ but a very similar color. Contrasts wonderfully with any color of tulip, whether your garden plan is classic or goth. Triumph tulips perennialize well in the garden if left uncut and fertilized after blooming. 16–18″ tall. Mid Spring blooms, Z3-7

Eve’s Favorite Fragrant Roses

These are among our favorite fragrant roses. While we grow and sell many of these, they are not always ready to be put out for sale, and quantities are always limited! Come by and view our current selection, and check our 2024 Rose list.

  • Banshee Rose

    “Banshee” (found) Z 4, dbl pink 2″ early & long-blooming May-June, rich sweet damask fragrance; large shrub or climber, no die-back, very disease resistant, very tough & tolerant of low water, poor soil, shade, once established. Distinctive matte foliage, fall color- purple, orange. Common in old neighborhoods all along the Front Range.Not terribly prickly. Cut armloads for big fragrant spring bouquets!

  • “Broadway Perpetual” (found, Boulder) Z 5 (4?) Large dbl strong pink quartered, deep old-rose perfume, spring & fall, sporadic in between. Good cut-flower. Seems somewhat shade-tolerant. Strong arching growth to 7’. Potential climber? Healthy foliage, moderately prickly.

  • Fairmont Proserpine, courtesy High Country Roses

    “Fairmount Proserpine” (found, Denver)

  • Abraham Darby (English) Z 4-5. Large, dbl, cupped, pink shading to apricot, repeats very well, strong scent, old-rose/fruity, good cut-flower. Heavy blooms are sometimes pendulous. Large, bushy shrub 5-6’ x 5-6’. Glossy disease-resistant foliage, stout canes are moderately prickly.
  • Alchymist (Lg. Flowered Climber, lg.shrub) Blooms very large, warm apricot shades, very double, looks English, very fragrant, haven’t grown.
  • Apothecary’s Rose (Gallica) Z 3. Very old; semidouble deep pink blooms in late spring on thin, erect prickly canes to 4’. Delicious sweet old-rose perfume. Tolerates some shade but may mildew. Perfect for herb garden.
  • Baronne Prevost (Hyb. Perpetual) France, 1842. Z 5 (4?) Fat globular buds open to large 4″, flat, very double, loosely quartered deep “rose-pink” blooms with rich damask perfume, repeats well through season. Rather thorny, large arching shrub to 6’x6’ or more. Good for wrapping on pillar, pegging, self-pegging, or climbing.
  • Cl. American Beauty (Lg. Fl. Climber) 1909 USA, Wichurana hyb. Z4 Large blooms are double, deep pink, paler on undersides, borne in small clusters on longish stems, strong Damask scent. In 1940’s considered the most fragrant climbing rose. Leaves dense & glossy, healthy. Vigorous growth to ~10’, tolerates some shade, neglect; profuse in June, sporadic repeat (esp. in cool summers).
  • Constance Spry (English) Bounteous, very large double pink flowers in late spring on a large arching shrub easily used for draping or climbing. Bred from the Gallica ‘Belle Isis’. Fragrance includes a hit of ‘myrrh’, present in a number of David Austin’s English roses.

  • Darlow’s Enigma

    Darlow’s Enigma (Cl. Hyb. Musk ?) Vigorous large shrub or climber of unknown origin with very disease-resistant, handsome glossy foliage. Small white semidouble flowers in clusters, borne throughout the season , are very sweetly scented. Very shade-tolerant. Zone 4.

  • Desiree Parmentier (found Gallica) Probably incorrectly identified as Desiree, this rose is found in old neighborhoods throughout the Denver metro area. Healthy, soft apple-green foliage on a shade-tolerant, suckering shrub to 3’ in sun and taller in shade. Flowers are unique – many deep pink petals tightly packed, radiating out from conspicuous green ‘eye’, forming a dome–shaped blossom. Blooms in June. Rich Old-Rose perfume. Buds also unique, appearing to have had their tops cut off. Blooms are produced singly, not in clusters, making it ideal for cutting. Thrives on neglect once established. No die-back in the Denver-Boulder area. Prickles are numerous but very short and non-threatening.
  • Fair Bianca (English) Lovely very double white blooms of old-rose style open flat and are produced in several flushes through the season on a shrub to 3’. Not very vigorous, but the fragrance is unique, including elements of licorice, lemon and myrrh.
  • Felicite Parmentier (Alba Hyb.) An outstanding, classic old rose, with compact, bushy growth to 4-5’ tall. Foliage is matte, slightly greyish green, and completely healthy, even in considerable shade. Blooms are small (1 1/2″), blush pink, double and densely double, borne in small clusters, with exquisite fragrance that seems to match its appearance perfectly. No winter die-back in our area, hardy to at least Zone 4.
  • Gertrude Jekyll (English) Bred from the Portland rose ‘Compte de Chambord’, which may be a better rose. Gertrude got HUGE in my garden, to 9’ tall, likes to bloom mostly at the top of the canes, hasn’t repeated very well, and is incredibly well-armed. Nevertheless, she’s worth growing for her fabulously fragrant, large, oldfashioned, double,flat pink blooms. Best grown with strict discipline (hard pruning) and protective armor.
  • Golden Celebration (English)

  • Golden Wings

    Golden Wings (Shrub) A healthy, vigorous, open shrub to 5-6’ tall and wide, with large, almost single lemon yellow blossoms accented by showy dark red stamens. The petals fade quickly to white in our strong sun. Blooms all season. Keep dead-headed ‘til August , then allow it to form attractive red hips. Hardy to Zone 5, maybe 4.

  • Heritage (English)
  • Jude the Obscure (English) Weird name for a gorgeous flower, double, globular, shading from cream to yellow to apricot, sometimes pinkish. Flowers ball in wet or very hot weather. Blooms occur in clusters of 3 to 8. Strong fruity fragrance with elements of peach, mango, etc. With disciplinary pruning, the shrub will be 5’x5’. Bright green foliage is moderately disease-resistant; Keep dead-headed to ensure good repeat.
  • Konigen von Danemark (Alba) The deepest colored of the Albas, Konigen bears medium pink, very double, 2″ flowers in June, blessed with delicious Old Rose fragrance. Totally healthy, matte grey-green foliage on arching canes to about 5’. Tolerates some shade. Hardy to Zone 4.
  • Louise Odier (Bourbon) Fully double, 2″ camellia-like pink blossoms are borne in great profusion in late spring, and again in pretty good numbers through the season. The fragrance is rich Old Rose. The shrub is very vigorous, theoretically to 5’x5′, but mine is 9’x9′, suggesting the need for a pillar, trellis or wall, or strong pruning. Mine never suffers any die-back, and is pretty healthy. Repeat bloom is best if you deadhead until some time in August. Pretty thorny, but not as bad as Gertrude.
  • Madame Hardy (Damask) One of the most choice Old roses. Beautiful, medium-sized pure white blooms with a green button eye on a robust, upright shrub to 5’-6’ tall. Very fragrant. June blooming, Zone 4.
  • Madame Isaac Pereire (Bourbon) France, 1881. Large, purplish, deep pink, cupped blooms are sumptuous in their appearance and perfume. Blooms are carried on short laterals from strong, large canes, and can be used as a climber to about 7’. Blooms are best if protected from very hot sun, but the plant is not really shade-tolerant. Hardy to Zone 5.
  • Mister Lincoln (Hyb. Tea) Black-red buds open to cherry red, richly fragrant at all stages. Blooms are large (4-4.5″), double, scrolled, high-centered, good cut. “Bush is upright and almost naturally urn-shaped, to 3’ or taller. Susceptible to mildew. Robust grower, reliable bloomer.” I haven’t grown this one yet.

  • Morden Sunrise

    Morden Sunrise (Canadian Shrub) A compact shrub, to about 3’x3’. Seems pretty tough in our test/display garden. Semi-double flowers open from orange buds, are 2 1/2 to 3″wide and shade from soft, tawny yellow to apricot pink, to orange. Moderately strong Tea rose fragrance is unusual for a Canadian rose, which are generally scentless. Hardy to Zone 3, almost continuous blooming.

  • Nuits de Young (Moss)Laffay, France 1845. A must for its fabulously purple flowers, this rose has also been called “Old Black”. Flowers are almost double, very fragrant, with velvety maroon-purple petals emphasized by golden stamens. Mossing on buds and flower stems has a pleasant lemony pine scent when rubbed. The shrub is compact and erect, to 3 or 4’ tall, and suckers. Foliage is small and dark green. We found this rose growing in Boulder’s Columbia Cemetery, where it has survived mowing, drought, and complete neglect for at least 65 years.
  • Pink Peace (Hyb. Tea) France, 1959. Enormous, intensely fragrant, very bright pink, double, with somewhat old-fashioned form, sumptuous flowers throughout the season on an upright bush. A slow starter, not exactly vigorous, but worthwhile for the blooms, which are long-lasting when cut. We know one bush in Paonia that’s about 40 years old, 4.5’.
  • Reine des Violettes (Hyb. Perpetual)

  • Rosa spinosissima

    Rosa spinosissima (Scotsbrier) (Species) My favorite species rose, as it perfumes my gardening hours with its strong, very sweet scent – one of the few fragrances that really carry in our dry air. The 4’ tall shrub is shade tolerant, and has very small leaves on gracefully arching canes that are covered with the lovely pure white single blooms for about 2 1/2 weeks in May. Hardy to Zone 3.

  • Rosa Mundi (Gallica) Ancient, sport of Apothecary’s Rose. Named for Rosamond Clifford, mistress to Henry II. Identical in all respects to Apothecary’s, except: Dramatic semi-dbl blossoms blush-white randomly striped & splashed with crimson & pink. Petals dry beautifully for potpouri.

  • Rose de Rescht

    Rose de Rescht (Portland or Damask Perpetual) A very distictive Old Rose, supposedly discovered in Iran. The flowers are small, 1 1/2″ or slightly larger, rich fuschia-red with strong purple tints, aging to magenta, very double, tightly formed rosettes, almost pom-poms, produced in small clusters amid lots of foliage. Exceptional strong Damask fragrance. Excellent repeat. The shrub is healthy, compact and bushy, to 4-5’ tall and wide. Canes are quite prickly. Hardy to Zone 4.

  • Rose du Roi (Portland or Hyb.Perpetual) Lelieur, France 1815. This is a rose with a story. Bred by a French nobleman loyal to Napoleon (the second one), it was appropriated and re-named by the King, Henri XV, when he regained power. It’s also an important rose for having introduced “red” color to rose breeding in 19th century Europe. The plant is compact and bushy, growing 3-4’ tall and wide, with large leaves (I’ve noticed they’re light green in spring, with later growth being dark green with grey undersides), and prickly canes. The flowers are fabulous, fairly large, double, red mottled purple with pink reverse, loosely formed when open, and very richly scented. Repeats, with especially good display in early fall. Hardy to Zone 4-5.

  • Sharifa Asma

    Sharifa Asma (English) Slow to establish, but worth the wait. Blooms are large, double, delicate shell pink, cupped, and blessed with a strong Old-rose and fruity (litchi) fragrance. Leaves are dark green, slightly leathery, and healthy as long as the shrub is not in too much shade. Growth is upright to 4’.

  • Stanwell Perpetual (Hyb. Spinosissima) The earliest repeat-blooming rose to begin flowering in my garden, vying for 1st with Reine des Violettes. Bred from R. spinosissima and Autumn Damask. Canes are very prickly, arching, dark red, clothed in very fine-textured foliage, and loaded with blooms in several flushes through the season. Flowers are double, small to medium-sized, blush pink opening flat and fading to white. Very sweetly scented, with characteristics of both parents. Growth is awkward the first few years, but then fills out nicely. Hardy to Zone 4.
  • Sweet Chariot (Mini) Tall for a miniature, to 2’. Small foliage and small pom-pom flowers in large clusters, unusual purple-pink color and lovely fragrance. Blooms repeatedly through season. Hardy to Zone 5.
  • Sydonie (Hyb. Perpetual) Extremely reliable repeat bloom, exquisite Damask fragrance, unique flower form. Flowers are “rose-pink”, 2-2 1/2″ very double, very quartered, with strongly in-curved center petals. They are borne on very prickly arching canes on a bush that’s supposed to be 3 1/2’ tall and wide. NOT. Mine is 8’x8’ and I’m planning to do some hard pruning. Hardy to Zone 4-5, I’ve never had any winter die-back.
  • Tradescant (English) I haven’t grown this one yet, but I’ve seen it elsewhere and loved the blooms. They are velvety black-red, very double, opening flat and quartered, 2-2 1/2″ wide, with a powerful Old Rose fragrance. Good cut-flower, holding its shape and color several days. Hardy to Zone 5. Reportedly grows best with hot summer weather.
  • Wise Portia (English) Compact, to 2 1/2’, I grow 2 of these planted very close together to form one shrub. Very large double flowers are a unique raspberry red, rosette shaped, with uniquely pointed, lotus-like petals. Heavy-blooming, richly scented, borne singly or in sprays. Excellent repeat if kept dead-headed ‘til late summer. Then it will form large, red hips. Modern-looking medium green foliage. Provide good light and good air circulation.
  • Zephirine Drouhin (Climbing Bourbon) Bizot, France 1868. Hardy to Zone 5-6. Our strain is definitely hardy in Boulder/Denver. Completely thornless, somewhat shade-tolerant, vigorous tall shrub or climber to 12’ on wall or arbor. New foliage and canes are burgundy colored. Flowers are loosely double, warm deep pink, medium-sized, profuse in spring and repeats regularly into autumn. Strongly scented- fruity Old-Rose.

 

Some fragrant roses to try at higher elevations:

Alba Semi-plena

Alba Suaveolens

Maiden’s Blush

Chloris

Konigen von Danemark

Rosa spinosissima

Rosa rugosa alba

Rosa rugosa ‘Magnifica’

Metis

Banshee

Gallica roses

Centifolia roses

Therese Bugnet

Morden Sunrise

Rugosa roses

A Soil Revolution

In this article, Mikl explains why Soil Health matters.

From Peak Soil to Soil Revolution

We are having a real revolution in our relationship with our soils. The turning point is our change in focus from soil fertility to soil health. In the last 60 years of the “Green Revolution” (i.e. the petrochemical boom), soil was viewed as a physical structure and fertility was viewed as a measure of chemicals in the soil — primarily NPK, nitrogen, phosphorus and potassium. The petroleum industry could make these macronutrients from natural gas, which make plants grow but often in poor health. Weak plants attract insect pests and fungal diseases, so more petroleum in the forms of insecticides and fungicides added to the success of the oil industry. But this approach has led to “Peak Soil” where land is losing productivity, crops are losing nutritional value, the soil is eroding at extreme rates, and the health of animals and people has declined.[Read More]

How Do We Manage Fireblight

Colorado is said to be the worst state in the US for fireblight, and 2018 was considered by many to be one of the worst years in Colorado. Fireblight is a serious disease affecting apples, crabapples, pears, Mountain Ash and hawthorn, and sometimes quince and pyracantha (supposedly up to 73 species of plants).[Read More]

Drought Resiliency

Drought resiliency is normally thought of as the ability to spring back after a drought or maybe it means tolerant of drought. But when a plant is stressed by having little water, its ability to survive and even thrive is influenced by other factors, some of which are Health, Vitality, Strength and Immune function.

The word Sustainability has become popular as a goal, but the word is too static. A more active word is Re-generative. We can “create” gardens that not only can maintain, but also support the abilities of Life to regrow, multiply, defend itself against predators and add to the vitality of other living things around it.[Read More]

July Color in the Xeriscape Garden

Xeriscape? Are you kidding? With all the rain we’ve been getting, isn’t the drought over?

As I understand our current water situation, water restrictions are still in effect for the Denver area, Colorado Springs has had a very dry spring until July and is under water restrictions, the Western Slope has been dry, New Mexico has been dry until July; and  Montana and South Dakota are having severe droughts. What this means is that the wonderful moist season we are enjoying in the Denver area depends on ephemeral conditions we cannot count on. In addition, much of our water comes from the Western Slope where weather patterns can be quite different from our own, so even if our gardens are getting watered, it doesn’t mean our reservoirs will be full. We live in a semi-arid environment and water conservation and xeriscaping will be increasingly important as our population grows, especially if global warming increases our temperatures.[Read More]

On The Dry Side

Plants that can survive and even thrive with little water are always valuable in Colorado where we get 15”-18” of precipitation most years. But when a real drought comes or when limited snowfall in the mountains means water restrictions down here, then xeriscape plants are essential in our gardens

Because the well at Harlequin’s Gardens nursery is so poor, my rockery garden has been on water restrictions for the last 25 years. Here are some plants that have performed well in my garden that is watered only 3 to 7 times a year.[Read More]

Some Drought-Tolerant Gems

Plants that tolerate or even revel in hot, dry conditions are always in vogue in Colorado. We may be blessed with moisture in the spring, as we had this year, but by June or July our vegetables need regular watering and east coast woodland plants are melting. There are some plants, however that are adapted to hot and dry conditions. Some are natives and some are from other regions of the world that have similar drought stresses as we have here.

These gems are ones that we have tested at Harlequin’s Gardens where none of our demonstration gardens are watered more than once a week, and others only 5 or 6 times a year. We can recommend these plants as successful and enjoyable under mandated or self-imposed watering restrictions.[Read More]

The 2002 Drought

Drought, Water Restrictions and Gardening: How Can They Go Together?

I think we were all caught off guard by this drought, by how fast we were forced to see dying trees and brown lawns and by the difficult discipline of watering restrictions. This was especially true in Boulder and Lafayette where mandatory restrictions began in May. Actually, 2002 is the third year in a genuine drought, which some of us without city water supplies can confirm. This year all around Boulder, Red Twig Dogwoods turned brown, linden leaves were scorched, Norway Maples suffered, many viburnums were looking very stressed, and trees in medians defoliated or died. Gardeners caught in the crunch between weeks of hot, dry weather and few opportunities to water, held off most of their planting projects; some started talking about moving away to where they could garden. For Denver and other Colorado cities, next year could be much worse.[Read More]

Three Xeric Plant Select Favorites

Here are three hardy, xeric and floriferous plants that are successful in western gardens.

Russian Hawthorn, Crataegus ambiguus was tested at the Cheyenne Horticultural Station and found to be well-adapted to the west. It is native to Armenia, Iran, Russia, Ukraine and Turkey. I have a 20 year-old specimen growing without irrigation along with many native shrubs. The mature size is 15′-20′ high and wide in our area. The branches grow quite horizontally which gives it natural character. It lends itself to a bonsai/character style, and I have been growing one in a big ceramic pot for 10 years. The finely cut leaves give a soft appearance and in May it blooms with profuse white flowers that are attractive to bees and butterflies and followed by showy red berries in August/September that are eaten by birds. Very dry conditions can result in fewer flowers and fruit. Like apples, to which Hawthorns are related, the seeds contain some cyanide, so should not be eaten, but the berries are edible and make a respected heart tonic.[Read More]

Beyond GMOs and Petroleum Farming

Four years ago I was among the group of Boulder County residents who were asking to ban GMOs on our publically-owned farm lands. The Commissioners at that time voted to add GMO Sugar Beets to the already approved GMO corn, but they also increased the acreage of land to be used for organic agriculture and agreed to take another look at neonicotinoid use if there was new evidence. There is now new evidence on GMOs, Roundup that is used on 80% of GMOs and on neonicotinoids linked to the death and weakening of all our insects, including bees.

So in 2011, in order to find out if there were practical non-toxic options to manage larger pieces of farm land (like 200-300 acres), I traveled to Ohio to an Acres USA Conference. Attending that conference were over a thousand farmers and ranchers. ACRES has been guiding eco-agriculture for 45 years now; the last conference I had attended was in 1977. I met farmers and attended talks by farmers who were managing 100-1000 acres without GMOs and without toxic chemicals.[Read More]

Quaking Aspens

Leave them to the Mountains OR Plant them at Home?

Populus tremuloides or Quaking Aspen is not only one of the best-known native trees here in Colorado, but it is said to be the most widely distributed tree of North America. Its narrow, roughly pyramidal form is commonly 25’-30’ tall and 15’-20’ wide, although it can get much larger. The leaves are shiny, dark green above and light gray-green beneath which makes the tree shimmer in the breezes. Also its whitish trunk adds to its attractive architecture. Then in the fall the leaves can turn a rich golden yellow which look glorious on the tree and lovely on the ground. It has a suckering habit which inclines it to clumps and which has put aspen in the running for the world’s largest being.[Read More]

Bigtooth Maple

Bigtooth Maple, Acer grandidentatum, is native to the far southwest corner of Colorado in a place known as Sleeping Ute Mountain. It is common in canyons, northfacing slopes and along mountain streams in Utah, Wyoming and west Texas from 5000′ to 8000′. Although most often listed as a separate species, Bigtooth Maple is sometimes called Western Sugar Maple, therefore, a subspecies of Acer saccharum. Its other names are Canyon Maple and Wasatch Maple.[Read More]

Bur Oak

BUR OAK—QUERCUS MACROCARPA-MOSSY CUP OAK

One of the most successful oaks for Colorado is the Bur Oak. It is adaptable to our clay soils and tolerates our alkaline conditions better than most oaks. In harsh, droughty areas this tree can be a low shrub, but on rich, river-bottom land can get 170’ high and 6’-7’ in diameter; but most often grows 50’-70’ high. The trunk is often thick and short with deeply furrowed bark, and the stout branches often extend almost straight out making the tree as broad as tall. The leaves are deeply lobed only in the bottom half and these lobes are rounded not pointed as with many other oaks. The acorns are distinctive in that there is a mossy fringe around the cap. The overall effect can be quite grand and sculptural, sometimes like a Chinese painting. The short taproot is surrounded by a massive root system which is strongly competitive. This is why old specimens often are standing alone.[Read More]

Catalpa

Western (Northern) Catalpa- Catalpa speciosa

It is surprising that a tree that looks so different from the other Colorado-adapted trees, is so successful. What stands out immediately are the huge leaves which can be 3”x 6” or even 6” x “12” and are heart-shaped. And in June, this large shade tree blooms exquisite, ruffled, bell-like, white, fragrant flowers with yellow and purplish coloration .And in the fall the passerby might be surprised to see the long thin pods 10”- 18” long.[Read More]

Champion Trees Show More Possibilities

Growing trees in Colorado, especially big shade trees, can be very challenging. Few of the specimens in our community “forests” are native to Colorado, and areas where big trees are abundant are often so different from our conditions that those trees do not adapt well here. Some of the difficulties trees face here are: alkaline soils, nutrient-poor and shallow soils, low humidity, hot and drying winter sun, strong winds, untimely wet snows in spring and fall, rapidly changing temperatures, and low rainfall. Add to these the confining root zones in which many trees are growing in urban environments, and it is easy to understand why our trees are often stressed, subject to borer and fungus problems, broken and short-lived.[Read More]

Kentucky Coffee Tree – Gymnocladus dioica

This member of the pea family (Fabaceae) can get 50’-60’ high and 30’-40’ wide, though most that I’ve seen in Colorado are under 45’. Nearly everybody thinks of this tree as interesting or picturesque.The branching is more open than most trees and the bark is gray to dark brown, rough and deeply ridged even on small branches. The leaves are  bluish-green and somewhat tropical-looking being double compound, each one 18”-24” long and forked with small leaflets alternating on the stem. Fall color is yellow. As the species name implies, this tree is dioecious, having the male and female flowers on separate trees. The flowers are greenish-white, supposedly fragrant and not conspicuous. On the female trees, tough, leathery seed pods follow that are 4”-6” long and 1 1/4”-2” wide. These hang on after the leaves fall and into the winter.[Read More]

Hackberry

Common Hackberry  (Celtis occidentalis)

Why would anybody be interested in a tree that is just the common variety? In this case, we Coloradoans can be very interested because “common” means it will grow just about anywhere. In our harsh country that provides a good living for people planting and replanting and pruning and re-pruning trees, the Common Hackberry is somewhat of a relief. It will grow to 7000’. Our 25 below zero winters do not bother it as it is hardy to zone 2, which helps a lot in adjusting to our sudden warm-to-cold swings. It is also not picky about soils, tolerating both acidic and our usual alkaline conditions; rocky is fine, heavy clay is OK; it really likes rich, moist, but grows right along in poor, dry, windy, polluted cities. [Read More]

How to Plant a Tree

Planting a tree puts us in touch with one of the most essential parts of a tree that is often overlooked—the roots. When a seed germinates, the first part to develop is the root. The seed has stored nutrients, but if the plant is to live, it must immediately make a relationship with the nourishment of the earth. Then it can make the sprout that pushes into the sunlight to start photosynthesizing. So the first matter of importance in planting a tree is to honor its roots—their condition, their future environment and their nourishment.[Read More]

Interview with Alex Shigo

Alex Shigo is a world-renowned authority in arboriculture, the science of trees. His delving curiosity and sharp scientific analyses carried him beneath the bark into a realm previously little understood. He worked 26 years for the US Forest Service investigating decay in trees, and through the process of dissecting over 15,000 trees with a chainsaw, he has uncovered much valuable information about tree structures and tree systems that have revolutionized the practice of tree care. As he puts it in the preface to his book Tree Pruning, “A major problem throughout the history of tree pruning has been the scant attention given to pruning as it affects the health of trees, while great attention has been given to pruning as it affects the desires of man.” Even though he is busy writing, giving workshops and talks and doing consulting, he agreed to answer some pressing questions for The Colorado Gardener.[Read More]

Mountain Ash

European Mt. Ash (Sorbus aucuparia)

This is surely one of my favorite ornamental trees for the front range which can be used up to 8000’.It is an upright oval tree spreading with age 25’-30’ tall aned 15’-25’ wide. If cared for, it will be attractive throughout the season. The bark is a shiny, orangy-brown. The serrated, compound leaves are dark green and in the fall turn yellow and reddish-gold. The clusters of flowers are white, blooming in spring with a peculiar fragrance that some people appreciate more when they’re gone. Clusters of red-orange berry-like fruit follow which color the tree through the fall, accenting the orangy leaf colors. These fruits are greatly loved by the birds and are in fact edible for people. They are known as Rowan berries and are used in Europe in making a brandy. In ancient times the Rowan tree, also know as the Quickbeam, was greatly revered by the Druids and used against lightning and witches’charms. The berries were considered extremely valuable having the “sustaining value of nine meals”, healing the wounded and giving a man the strength of ten men. I had to try this, of course, and found I couldn’t eat even 10 berries. Later I learned they need to “blet” or shelf-ripened. The birds do spread these around, and Mt. Ash seedlings are not uncommon.[Read More]

Pinyon Pine – Pinus edulis (Pinus cembroides edulis)

The Pinyon Pine has several advantages over other evergreen trees in a Colorado landscape. For one thing, its size doesn’t consume so much horizontal space. Compare the modest mature Pinyon at 10’-15’ in diameter with Austrian or Ponderosa at 25’-35’ diameter or Blue Spruce at 30’-40’ diameter. A few of these “average” sized evergreens look innocent when freshly planted, but who hasn’t seen them blocking sidewalks and doorways, tearing off gutters and shading solar collectors and windows in the winter? The Pinyon with its gently rounded top only gets 12’-20’ high, which suffices for many screening needs and still leaves the view. If it isn’t crowded, it stays branched to the ground with dense foliage of short, medium green to gray-green needles, two to a bundle. The cones are small 1 1/2”-2” long, brown to reddish-brown, which open to a rosette form and in the wild yield Pinyon “nuts”. These seeds are good-tasting and oily, with a piney flavor much appreciated by birds, animals and humans. They are also nutritious, being higher in protein and carbohydrates than pecans, but lower in fat. For some reason , these “nuts” are unlikely to develop in small urban plantings.[Read More]

Redbud

One of the most beautiful ornamental trees is the Eastern Redbud, Cercis canadensis. It is a native of the eastern and southern U.S. and has “naturalized” in older Boulder neighborhoods. It’s most distinctive feature is its reddish purple buds  followed by intense purplish-pink pea-like flowers in late April before the leaves come out. This wondrous and heart-warming display is greatly appreciated so early in spring but cannot be counted on if winters are too harsh.

It is a smaller tree 20’-25’ high and wide with attractive bark and heart-shaped leaves which are shiny and purplish when young. Fall color is yellow. It is said to be hardy  to zone 4 and we have many fine specimens in Boulder.[Read More]

Small Trees for Eastern or Northern Exposures

Shade trees 40’-60’ high and wide are great on the south and west sides of our houses and offices. They reduce temperatures and reduce cooling costs in the warm months, but they are not always appropriate. We don’t want dense shade where we grow most xeriscapes, rock gardens, herb gardens, most natives and many perennials. In addition, there is no need for big shade trees on the north side, and the morning sun is usually welcome on the east side of our houses and workplaces. And many plants prosper in morning sun and afternoon shade. It is also significant that a 20’ tree costs far less to have pruned than a 40’ tree. So it seems to me we should be growing small trees under 30’ tall on the east and north sides of our buildings.[Read More]

Stressed Trees: How to prune and care for them

Trees have it hard in Colorado. If it’s not the shallow and lean topsoil, it’s the low rainfall and low humidity, or it’s the heavy wet late spring or early fall snows, or like last November, it’s the dramatic temperature changes. After a warm and beautiful fall without a killing frost until November 11, we experienced a 77 degree drop in temperature between November 10 and November 12. This was one of the three largest temperature drops ever recorded in the Denver area, the other two were in December 2013 and January 2014.[Read More]

What’s Blooming in July?

Pestemon x. mex ‘Red Rocks’

Despite the heat, July blooms are glorious!  At Harlequin’s Gardens we’re often asked to help identify July blooming plants and to provide suggestions for summer blooms. With that in mind, we’ve put together a thorough list of What’s Blooming in July. See what will inspire you!
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Supporting Trees in Colorado

Trees do a lot for us humans, so we shouldn’t forget to give them some support. When I look at the treeless ten acre lot next to our nursery, or when I see an old photo of the CU campus with bare land around Old Main, I remember why we can’t take trees for granted in Colorado. Trees really have it hard here, but there are things we can do to help them survive and thrive.[Read More]

Tree Roots 1: The hidden support system

The roots are the hidden support system of our giant plants, the trees. They anchor their woody trunks to the ground, store food and bring in water, nutrients and oxygen. In this article I will discuss what is going on down there. In the next issue I will discuss more practical applications of this understanding.  

Far less is known about tree roots than about the trunk, branches and leaves. This is understandable since the roots are hidden from our view, and once you dig them up, they are no longer what they were. We are awed by the massive trees swaying over our houses and streets, but usually we give little thought to what is going on under the surface. However, when spring thawing is followed by powerful winds and we see an 80’ spruce toppled over with its roots in the air, which are only 9” deep; that gets us thinking.[Read More]

Tree Roots 2: The hidden support system part II

What would we do without trees? What structures could we invent and construct that would hang over our houses and offices, providing shade and cooler temperatures? Such a structure would have to hold up under 80 mph winds and heavy wet snows, and would have to retract in the winter to let in light. Trees provide these values and much more, giving off oxygen, providing housing for birds, and protection for understory plants. Thus it is very important to take good care of our trees, and the most fundamental level of that care must be directed to the roots.[Read More]

Biological Farming and Gardening

A New Model for the 21st Century

A newer science that is not tied to petroleum profits is emerging to challenge the industrial approach to agriculture and gardening. Of course, the enormously powerful and politically connected corporate giants like Monsanto, Bayer and Dupont will continue to make money, but after 60 years of dominance, the “Better Living Through Chemistry” model can no longer hide its fatal flaws. Mountains of evidence now point to the effects of chemical agriculture: poisoning the earth, driving global climate change, causing major health problems, killing pollinators and destroying the life of the soil. The good news is that a more long-range, wholistic view is starting to take its place. This new approach is being called Biological Agriculture and Gardening.[Read More]

Biological Thinking

It has been suggested that this period of the 21st Century might well be called The Age of Biology, because the biggest challenges will be biological and the biggest breakthroughs will be in the realm of biology.

In this article, we will continue the discussion from the last issue on Biological Agriculture and Gardening, but this time going into specifics of biological thinking, biological discoveries and applications that improve plant and food success with biological solutions.[Read More]

Food Safety and GMOs

Food safety is one of the most critical issues of our time. What we eat is directly related to our health, and health care has a direct impact on our personal and national economies. Major chemical companies like Monsanto, Bayer, Dow and Dupont have introduced 86,000 synthetic chemicals into our environment, food, drugs, cosmetics etc and most of them have never been tested for toxic effects on human health and the environment. Since the mid 1990s, some of these same companies have been filling our grocery stores and feed stores with genetically engineered food products which may be causing serious health problems but are being approved by our government without safety testing.[Read More]

Gardening from the Heart

Most of us were taught that gardening is about control, about battling unruly, ravenous nature to succeed with our objectives. And a very complex and prosperous industry sprang up in the late 1940s to provide us with the power and weapons to meet those expectations. Petroleum products from World War II chemical weapons, defoliants and bombs were reformulated to solve our plant problems and feed the world. These chemical fertilizers, pesticides and herbicides have now had 50-60 years to show that this aggressive, heartless and poisonous approach has failed. Foods with little nutritional value and a polluted world are inspiring a strong international movement toward sustainability.[Read More]

Gardening Without Fear

The key to minimal maintenance and a low input approach is Gardening Without Fear. The solution to gardening without fear is twofold: being empowered to garden successfully and being relaxed and tolerant. If we are fearful, we will react to every little problem, worry and criticize ourselves. Then we might seek an immediate solution like some poison.

We have been guided to believe that we need these petroleum products by companies that sell them. In fact, these products weaken the support systems of plants and make them more vulnerable to diseases, pests and drought. The truth is—we don’t need them.[Read More]

Invasive Plants and Weed Profiles

Last month we raised the issue of invasive introduced plants and the idea of being responsible gardeners who respect our native habitat and make an effort to not release invasive plants into the wild. We began with obvious noxious weeds that are having strong negative impacts on our native populations of plants and animals. This month again I am profiling weeds which have been declared as noxious, but this time a question is beginning to arise about under what circumstances are some of the less aggressive weeds invasive? In other words, is it possible that we might find a middle way that guides us strictly with the truly harmful invasives and more leniently with the less aggressive and more useful weedy plants? These are questions I am asking myself and will be asking in future interviews. We also welcome your views on this issue.[Read More]

Invasives August Issue

In February 2000 President Clinton established the National Invasive Species Council. Agriculture secretary Dan Glickman, Commerce Secretary William Daley and Interior Secretary Bruce Babbitt were asked to work together on a plan to minimize the economic, ecological and human health impact of invasive plants and animals not native to the US. The executive order on Invasive Species directs federal agencies to prevent the introduction of invasive species, to control populations of such species in a cost-effective and environmentally sound manner, to monitor populations, restore native species, conduct research and promote public education on invasive species.[Read More]

Invasives Intro

One of the hot subjects in horticulture these days is the issue of the invasiveness of introduced plants. Since they did not evolve here, they lack natural enemies, and whereas most are harmless, some have engulfed vast areas of wilderness, national forests, range and farm lands. This has led some people to campaign for “natives only” and others to attack the introduction of new plants as an ecological nightmare. In response to these attacks some in the plant industry have dismissed these fears as invalid over-reactions. As Colorado gardeners, most of us can be both excited by new plant introductions that are well-adapted to Colorado conditions, and feel very protective of our natural ecosystem and our native plants. In a series of articles, we hope to uncover some truths regarding these issues and to educate ourselves about how to work with this situation in a constructive manner.[Read More]

Nitrous Oxide

The forgotton greenhouse gas and how it relates to growing plants

Nitrogen is one of the most essential nutrients for plants. Nitrogen is required for building amino acids, DNA and RNA, in stimulating growth, supporting health and is a critical ingredient in chlorophyll, the chemical needed for photosynthesis. In our gardens, when nitrogen is lacking, plants are small and yellow, and roots do not perform well. In Colorado, almost all our soils are deficient in nitrogen and organic matter. So we gardeners often add fertilizers and composts to our soils.[Read More]

Pea-Planting Advice

Local advice from our friend Elizabeth:

Hi All, I have been trying a new technique (at least for me) of starting peas in sections of guttering (which I got at Resource) in the greenhouse, growing them on until they are about 4 inches tall, and then transferring them to a trench in the garden.  So far it seems to be working fairly well. The peas germinate really fast and grow quickly in the greenhouse. You could probably do it in a house too. I plug up the ends of the guttering with a piece of foam and duct tape. When I am ready to transfer them, I dig a trench, remove the foam and duct tape, spread the sides of the guttering away from the soil, and slide them out of the guttering into the trench. The sliding is the tricky part.  I have found it takes two people to go well: one to guide and encourage the peas along, and one to lift and shake the guttering, as you have to get it to a fairly steep angle for the peas to slide. I’m using galvanized guttering, but plastic might work better as it would be smoother. There’s lots of videos of this on the web. Thought this might be a good solution to slow germination in our really unpredictable springs.

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Canadian Roses for Colorado

The Canadians, like their English and French ancestors, have a great love of roses. However much of Canada is in zones 4, 3 and even zone 2. Therefore many of the hybrid tea and floribunda roses bred in modern times have not been tough enough for Canadian gardeners. So the Canadians set their own federal agriculture department to work on breeding roses that succeed in Canada. Not only do these roses do well north of our border, they are very successful in Colorado, even in our higher elevation environments. Our 10-20 below zero winters and dramatic temperature changes can kill or significantly injure more tender roses like the hybrid teas and floribundas. So gardeners in Colorado who don’t have time to remove large masses of dead canes, hill soil around the canes to protect them for winter, and who have less inclination to spray and fertilize frequently, find the Canadian-bred roses provide a rewarding and easy-care alternative.[Read More]

Difficult Broadleaf Evergreens for Colorado

In the last issue I discussed the easy broadleaf evergreens for Colorado and this time we will go into the difficult ones. Many people have killed or had poor success with rhododendrons, hollies, azaleas and daphnes etc. so it is good to understand these plants further. Unfortunately in my sunny, low-water gardens, I have had little experience with them so I went to two people who have plenty of experience, Don Zaun and Allan Taylor.[Read More]