Harlequins Gardens

Boulder's specialist in well-adapted plants

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4795 North 26th St • Boulder, CO 80301

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Bulb Tips from Eve

Species Crocus are the earliest Crocus to flower, at least two weeks before their Large Flowering siblings, and are the best for early spring lawn tapestries: hold off mowing the lawn until the foliage has died back. Drifts are also lovely in garden borders and rock gardens. Plant 4” deep and 3”- 4” apart, about nine bulbs per square foot for a dense planting. (Crocus are also good for forcing indoors over the winter. Pot them up in mid-October and pre-cool them at a consistent, dark 38 to 45 degrees F for eight to ten weeks with moderate watering. Bring them into the house ~ they will bloom about four weeks later.)

 

Narcissus (Daffodil) Culture

Narcissus are easily grown in average, medium, well-drained soil in full sun to part shade. Best in organically rich, sandy to loams that drain well. Plant bulbs 4-6″ deep and 3-6” apart in fall. After the flowers have bloomed, the top portion of each flower stem may be removed, as practicable, to prevent seed formation, but foliage should not be cut back until it begins to yellow. Flowers usually face the sun, so bulbs should be grown with any shade areas at the rear of the planting. Bulbs can be left undisturbed for a number of years.

RELAX! RECONSIDERING GARDEN CLEANUP

Autumn has declared itself on the Front Range, and many gardeners are itching to bring a close to the gardening year by tidying up. But wait! There are some important issues to consider here before bringing out the rakes, blowers, clippers and shears.

Now is a great time to take a long look at your gardens and make notes on successes, disappointments, gaps, and changes that you’d like to make. Assess the ecosystem you have created, and think about how you can make it even more supportive of our precious wildlife, beneficial insects, pollinators and soil life.

A certain amount of garden cleanup is very important for reducing diseases and pests that are difficult to control. If you haven’t already done so, do remove diseased plants from your vegetable garden. You should have been removing and treating diseased foliage from roses or shrubs with fungal diseases like mildew, blackspot or rust before now, but if their disease-carrying foliage is falling now, keep them picked up and dispose of them responsibly.

But don’t be so quick to scalp those perennials and annuals! Many of them provide natural food and shelter sources that wildlife and beneficial insects depend on for winter survival. You may not have noticed, but so many beneficial insects and butterfly larvae spend the winter in the (often hollow) dead stems. If you throw them out, you’ll lose most of the beneficials that would otherwise keep the balance next year. Always keep an eye out for egg cases attached to stalks when you prune or clean up. There’s often an aesthetic side-benefit – many seed-heads look fabulous either crowned with snow or silhouetted against the snow-covered ground.

Some perennials die back to below ground (peonies, gas plant, golden banner, balloon flower, desert four o’clock, gayfeather, gas plant, leadwort/plumbago, etc.) leaving no basal growth and leaving a completely blank space. To make sure you don’t forget where they are and accidentally dig them up or step on them, leave dry stems until the new growth begins to appear in spring.

Unless you have an ‘ornamental’ grass that self-sows aggressively, leave grasses and their seedheads standing. If they are ‘cool-season’ grasses, you’ll want to leave them until about mid-February, then cut them to 3” above the ground so they can begin making unimpeded new growth as soon as the soil thaws. Dormant ‘warm-season’ grasses can remain attractive until warm weather comes and don’t need to be cut down until April.

Leaving dry stalks standing in the winter also helps preserve soil structure. Snow collects between the stalks and provides protection from freezing temperatures by insulation for the crowns of the plants, especially important for marginally hardy plants. Captured snow keeps soil temperature more consistent, protecting from extreme temperature fluctuations, and helps prevent the alternate freezing and thawing that can disrupt mycorrhizal networks (and uproot plants, especially new and small ones).

Leave the leaves! The larvae of many butterflies overwinter in the blanket of autumn leaves, as well as other beneficials. The leaves also provide cover for frogs, toads and spiders. Songbirds eat more than just seeds; they search in the leaf litter for insect eggs and caterpillars. As they naturally break down over time, they feed the soil microbes that make nutrients available to plants. Worried about harboring snail and slugs? Before those leaves begin to fall, spread a non-toxic slug bait like Sluggo in areas of concern. You may want to remove leaves and twigs from patios, decks, walkways and lawns, and that’s fine – especially if you can spread them under shrubs or pile them in a corner where they’ll remain undisturbed through the winter. And very large, flat leaves from trees like Basswood (Tilia americana), Norway Maple, Sycamore/London Planetree) should be cleared from beds or they can form a slick solid mat that smothers the crowns of smaller plants.

Xeriscape: Native Plants

Achillea lanulosa (Achillea millefolium var. lanulosa) (Yarrow)

Agave parryi neomexicana

Amelanchier alnifolia (Serviceberry)

Amorpha canescens (Leadplant)

Aquilegia barnebyi

Aquilegia caerulea (Rocky Mt. Columbine)[Read More]

Climate Strike 2019

“On September 20th, young people and adults across the US and world will strike to tell the UN and leaders across the world that we want climate action. By growing and uniting the multi generational climate movement, the strike is the launch of a new era for just and equitable climate action.”

– Rocky Mountain Peace and Justice Center

 

Harlequin’s Gardens is joining the Climate Strike, Friday Sept. 20th, by striking while the iron is hot, increasing the focus on the Climate Crisis.

At Harlequin’s Gardens we will not be leaving our jobs on September 20. Instead we will be at work for Harlequin’s where we are always working to help you and the planet. AND we will be giving away one Free bag of compost with each purchase, on Friday, the 20th.[Read More]

2019 Tomato Tasting Results

This year’s tomato tasting was a great success, with a total of 41 tomato varieties present over the 3-hour event!

Participants brought in some wonderful new varieties this year, including Pink Bumble Bee Cherry, Gajo de Melon, and Blue Cream Berries. We always take people’s votes into account when deciding which tomato varieties to carry, so 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! A huge thank-you to Growing Gardens for providing our the location, helping us publicize the event, and for bringing us some fabulous volunteers. Thank you also to the volunteers of Slow Food Boulder County. We couldn’t have done it without you!

2019 Taste of Tomato Vote Tally

 

 

 

 

[Read More]

Lycium (Goji Berry)

Whoever heard of Goji Berry 20 years ago? Now, with the current interest in superfoods, phytonutrients and antioxidants, Goji Berry juice and dried fruits can be found in many urban grocery stores. The 70+ species of Lycium are found on most continents and one species, Lycium pallidum, is native to Colorado. But the best known and most grown Goji is Lycium barbarum, the Chinese Wolfberry, also known as Matrimony Vine, Desert Thorn and Boxthorn. What is not commonly known is that this exotic superfood can be easily grown in Colorado.[Read More]

Insectary Plants: Let Nature Manage the Pests

It’s a common idea that Nature, left to its own devices, comes to some kind of balance. If one organism gets too numerous, something else will increase to reduce that population. In the case of monocultures created by humans, there is an enforced imbalance that has to be propped up with lots of energy and effort. So in the pursuit of sustainability, humans are opening our eyes to the possibility of biomimicry, imitating Nature. We are coming to the realization that biodiversity is far healthier and less energy intensive than monocultures born out of the aggressive hubris to control Nature. “Let Nature take her course.” But we can stack the deck in human favor first.[Read More]

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]

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]

2011 Plant Select Winners

Plant Select is a 25 year old cooperative program combining the efforts of Denver Botanic Garden, Colorado State University and some members of the local green industry. Their intention is to chose, propagate and promote plants that are well-adapted to Colorado conditions, colorful and are either little known or underutilized. The 2011 choices are a particularly excellent group.[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]

What’s Blooming in July.

Platycodon grandiflora – Balloon Flower

Despite the heat, July blooms are amazing

Every summer after we cross the Summer Solstice and temperatures rise, we humans begin to wilt from the heat, while so many plants rise up in full glory!  Rose blooms are abundant in color and fragrance; Delphiniums, salvias and penstemons are sending up their bloom sentinels luring pollinators, and clematis twirl their way around our trellis’ and our hearts. Pictured right, Platycodon grandiflora, Balloon Flower.[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]

Xeriscape Herb Garden

Usually when we talk about xeriscape gardening, we think of rock garden kinds of plants or natives, but there are a lot of herbs that survive and even thrive in low water conditions. I learned about this from my own herb garden which went from low water irrigation to next to no watering. It had been established for ten years and then three years ago, I had to cut back the watering to only a couple times a year.[Read More]

Planting Instructions for Roses

Planting Container-Grown Own-Root Roses

Thank you for buying your roses at Harlequin’s Gardens nursery! To get off to a good start for growing beautiful, healthy roses, please follow these planting instructions. Please read them through before you begin.

WHEN: Many of our roses have been over-wintered outdoors; these may be planted as soon as your soil can be properly dug and worked. Otherwise, in Colorado’s Front Range region, plant roses after the average “last frost” date (in Boulder,May 15). Roses that have just arrived from greenhouse growers may need to be “hardened off” for 4 to 7 days prior to planting. Keep them outdoors in a place where they’ll be somewhat protected from sun, wind and major temperature changes (you can bring them into a garage or shed temporarily to wait out a late frost or storm). You can plant roses all through the summer, as long as you can keep them watered. And we’ve had great success with fall planting, well into October, with monthly winter watering.[Read More]

Cherry Trees on the Front Range

According to some reports, Colorado weather in 2014-2015 has resulted in the deaths of 80% of our cherry, plum and peach trees. How did this happen? Does it make sense to replant? And if so, how can we reduce future losses and increase fruitful successes? This article will focus on cherry trees.[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]

Big, Bold, and Beautiful

If you’ve got room for some big splashes of color in a garden that is not pampered with water and fertilizers, here are some tough natives that will pay for their real estate.

Desert Four O’Clock, Mirabilis multiflora is a Colorado perennial that, like its annual cousins, blooms from late afternoon to mid-morning. The trumpet-shaped flowers are of a rich purplish rose color and virtually cover the foliage when the flowers are open, blooming for several months starting in July. The leaves are thick and blue-green. They look so innocent as seedlings, and then they grow and grow to a 3’-4’ mound, 1 ½-2’ high. The stems lie on the ground, providing a mulching effect.[Read More]

Eve’s Favorite Fragrant Roses

  • “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 inbetween. Good cut-flower. Seems somewhat shade-tolerant. Strong arching growth to 7’. Potential climber? Healthy foliage, moderately prickly.
  • “Fairmount Proserpine” (found, Denver)

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Growing Roses Without Chemicals

Here is the basic approach which we use at Harlequin’s Gardens to grow hundreds of roses without using any pesticides or fungicides, and only using a few soft controls.[Read More]

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]

Growing Agave in Colorado

Most of us in Colorado know that Agave is the source of tequilla and Agave sweetener, but fewer have seen it growing here. Even more rare is the sight of Agave in bloom. The Century Plant doesn’t really take 100 years to bloom, but it does seem to take forever. After 13 years, my Agave parryi, whose bold and armed rosette finally achieved 31” in diameter and 16” tall, began this May to push up a bloom stalk. Then it skyrocketed 3”-4” A DAY until it reached eleven and half feet tall with a candelabra  of rich yellow flowers. Eclectic horticulturist Bob Nold says in his book High and Dry, “Their flowering, mostly, is as spectacular a thing as the plant kingdom has invented….”[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]

Drought Water Restrictions

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]

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]

Opportunities and Tricks of Xeriscape

Since the drought of 2002, there has been some real progress in understanding and appreciating xeriscape or water wise landscaping. And yet some people think the drought is over and that we can go back to assuming that we have as much water as we want. But it is quite possible that we could have more droughts, and it would be painful to be as unprepared as we were in 2002. That was our wake-up call. And even with the moister weather in recent years, peoples values are changing. They are more interested in sustainable landscapes, and they want more economical landscapes and gardens that need less water, time, energy and money. And of course that means using plants and methods that are adapted to Colorado conditions.[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]

Testing Xeriscape Groundcovers

TESTING XERISCAPE GROUNDCOVERS TO REPLACE LAWN AREAS

Whether this turns out to be a drought year or not, the idea of conserving water is probably as vital to our future as educating our children. As long as the human population grows, the demand on our water reserves will continue to rise, forcing eventual water-rationing even if the supply stays the same. And as we have seen this year, we can’t count on a bountiful supply from the heavens. Ten years ago these ideas, and the fact that my own water source is a very low-producing well, got me to thinking about how much water we use in Colorado to water our lawns. We know that xeriscape plants use less water than bluegrass, so why couldn’t we use large areas of certain low-water plants to replace lawn, which could greatly reduce the demand on our valuable water? In order to test a variety of xeriscape plants that might function as replacements for Kentucky Bluegrass, I built a 104′ x 6′ demonstration garden which will be on the 2002 Xeriscape Garden Tour, taking place in Boulder June 29th and 30th.[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]

Xeriscape Perennials That Withstand Colorado

“The quality of mercy is not strained
 It droppeth as the gentle rain from heaven.” Shakespeare

It was great to have a long cool spring with plenty of moisture, but since it followed the very hot temperatures and drought of 2002, it really felt like a merciful blessing. Now instead of dying trees and brown lawns, the streams are gushing, the reservoirs brimming, the wildflowers are extravagant and the birds are joyfully singing. Those plants and gardens that survived 2002 have never looked better. We’ll take it.[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]

The Drought Response

Responding to the worst drought in 100 (300?) years has been confusing, disturbing and difficult. The main unanswerable questions are, “How long is it going to last?” and “Is global warming or other conditions going to cause this kind of drought to be more common place?” Implicit in these questions is the question being asked by water utilities, city governments and members of the Green Industry: “How much money should we invest in changes that will conserve water?” If in two years the drought is over and will not be this bad again for 100 years, then why bother to reinvent our utilities and businesses? On the other hand, if water providers, city councils and the Green Industry are not proactive about water conservation, and the drought cycle lasts for a long time, consequences could be devastating, and the public could get furious.[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]

Why Plant A Once Blooming Rose?

I know of one lilac that has some repeat flowering in the fall, but I’m not aware of any spireas, mockoranges, shrub honeysuckles, forsythias, serviceberries, butterfly bushes, rabbitbrushes, cotoneasters, or other shrubs that repeat their flowering cycle. Why is it, then, that many gardeners demand continuous flowering roses ? We want them, of course, because they exist.

The fixation on constant flowering is encouraged with annuals, which, of course, don’t really start blooming until late spring or summer and then the first winter, they die. And seasoned gardeners know that the search for perennials that “bloom all season” leads to the proper selection of many species that will bloom in succession. So when we hear of roses that bloom from May or June through September, we think we have found the holy grail. However there are qualities besides repeat flowering which could entice us to cultivate the so-called “once-blooming” roses. I would like to share these not-so-obvious reasons with you.[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]

Sustainable Roses for Colorado

Tea House Roses, photo by Nikki Hayden

Roses are certainly one of the world’s most beloved flowers, and yet many people have given up on them because they have gotten the reputation of needing frequent spraying, feeding and fussing. They got this reputation because for decades, hybrid tea and floribunda roses were bred mostly for special colors, a particular flower form and repeat flowering. Their value was judged more for the exhibition table than for the garden. Now, as more people have become aware of the dangers of pesticides and as the trend has moved to “care-free” shrub roses for the garden, rose breeding has shifted in the last ten years towards more sustainability.[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]