Harlequins Gardens

Boulder's specialist in well-adapted plants

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Home | Blog | Perennials

Perennials

Help Fall Plantings Beat the Heat

Fall is among the best times to plant perennials. While we may begin to wilt from late summer heat, many plants rise to the occasion and burst into bloom!  As days begin to grow shorter, perennials spend the next few months developing root systems or taproots that delve well below the hot, dry surface soil. Pollinators depend on finding pollen and nectar sources through the entire summer, so it’s important to include late-summer and autumn bloomers in your garden. 

Here are a few suggestions for successful planting.

[Read More]

Thanks, Volunteers!

Gary Meis teaching

Gary Meis teaching

Last Saturday a group of dedicated plantspeople came in from the cold to learn and volunteer with Harlequin’s Gardens’ expert propagator Gary Meis. We’re passing a few of his native plant seeding and propagation tips along to you.

[Read More]

Daylilies Shine in Mid-Summer

Daylilies are old favorites for good reasons. They are:
Low maintenance
Cold hardy (to USDA Zone 3)
Moderately drought-tolerant
Very attractive to butterflies and hummingbirds
Adaptable to a variety of soil conditions
Disease-free and pest-free
Graceful, eye-catching, and long-blooming
Available in a very wide range of colors and sizes
Rabbit-resistant
Fast-growing
Good for erosion control
Edible and tasty

And we still have some wonderful varieties in stock! And they are in bloom!  [Read More]

Harvest Time

I don’t know about you, but I’ve had to forego some of my morning rituals to make time to reap the bounty from my garden these last couple of weeks. I fully expected the temperatures in the 90s and occasional triple digits to stall the production of my tomatoes, but somehow the blossom-drop and lack of fruit-set experienced in previous very hot summers never materialized, and now I’m bringing in armloads every few days! And how about them eggplants! Swiss Chard, Collards and Kale abound, and my Tromboncino climbing Zucchini is feeding the neighborhood.

I have two new tomato varieties to add to my list of top favorites: Tidy Treats and Tasmanian Chocolate (I’m a sucker for anything with chocolate in the name or ingredients list).

[Read More]

Perennials in 1-gallon Pots

At this time of year, when the weather is hot and mostly dry, it can be easier to establish transplants that already have a larger, deeper root system. Another very important factor in successful transplanting in this heat and drought is the quality of the potting soil the plant was grown in. Harlequin’s Gardens doesn’t use a commercial, lightweight, soil-less mix, designed for using chemical fertilizers and for minimizing shipping costs. [Read More]

Unique Peonies

We have a limited number of choice Peonies in 2-gallon pots, ready to make a long-lived presence in your garden! These varieties are different from the ones we will have in stock in a couple of weeks, which will be in 1-gallon pots.

Peonies are classic garden plants that add a lot of charm and beauty to the garden, increasing in size and beauty for many decades. Their gorgeous, fragrant blooms and lush foliage have made them popular for many years. When a peony is finished blooming, the attractive foliage mound makes a great seasonal ‘shrub’. And, of course, the sensuous flowers make stunning bouquets. Cut them when the buds have swelled and are beginning to open slightly. [Read More]

Special Plants to buy now!

We propagate and grow a lot of great plants here at the nursery, which gives us (and you!) an advantage when the wholesale suppliers run short in mid and late summer. We’re very pleased to have beautiful stock of some highly desirable and hard-to-find shrubs and perennials right now, including some choice native plants, Plant Select® winners, and customer favorites.

Here are some brief profiles of some of our best current offerings. And this week, Harlequin’s Members can buy them for 20% off!  [Read More]

Cutting Back Ornamental Grasses

Historically February is one of Colorado’s snowiest months, and finally we’re beginning to see evidence of that this year! Additionally, the forecast indicates more to come.  It remains to be seen how some of our marginally hardy garden plants have suffered from the below zero temperatures.

Many of us may have the tops of ornamental grasses and various perennials peeking out of the blanket of the snow, which provides habitat for overwintering beneficial insects and it helps to keep the plant roots and crowns warmer. But very soon it will be time to cut back Cool-Season ornamental grasses before their active growth begins, which will allow light to penetrate the entire clump.  See Eve’s instructions, below. [Read More]

Alpine Plants

Explore the spectacular floral displays of the Continental Divide while you can!

Hiking the West Ridge Trail on the Continental Divide

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Native Plants We Often Have for Sale

These are native plants that we often have for sale. Availability does change every year, but we grow and buy a wide variety of natives because they are so successful in our gardens.

KEY: t = tree, s = shrub, v = vine, gr = grass, gc = ground cover, p = perennial,

b = biennial, a = annual

Abronia fragrans (Sand Verbena) (p)

Acer glabrum (Rocky Mt. Maple) (t)

Acer grandidentatum (Bigtooth Maple) (t)

Achillea lanulosa (Native White Yarrow) (p)

Agastache cana (Hummingbird Mint) (p)

Agave parryi (Hardy Century Plant) (s)[Read More]

Ready, Set, Plant!

What a storm we had last week!  With the windy conditions and record-setting low temps, everyone’s gardens looks very different this week and may need some attention.  If you haven’t already, this is a good time to review our blog about garden cleanup. The good news is that soil temperatures have cooled down to the optimal soil temperature for bulb planting, ~50 degrees.  And, our current mild daytime temps and above-freezing nighttime temps are ideal for planting perennials, and still good for planting roses, shrubs and trees. Inoculating with mycorrhizae and attention to fall and winter watering are the keys to success.

Bulb Planting and Tulipa ‘Paul Scherer’

Starting with bulb planting:  Recommended planting depths are to the bottom of the planting hole where the base of the bulb rests.  Planting depth can vary depending on how light or heavy your soil is – plant deeper in light soils, shallower in heavier soils.  (If you’re in doubt, a general rule is that planting depth is 3 times the height of the bulb.) 

You don’t have to dig a single hole for each bulb!  You can dig a large hole, say 8-14″ wide by 16-24″ long, to accommodate a large grouping, or swath of bulbs.  This is a great way to save time, to create a more naturalized look, and to combine two or three types of bulbs in one grouping. 

Single Early, Triumph, Darwin Hybrid, and Multi-flowering tulips should be planted 8″ deep to perform as perennials, and fertilized each year just after bloom. Be sure to allow the leaves and stems to wither naturally before cutting them down.

You may want to sprinkle bone meal in the bottom of the hole so that it can touch the bulb roots.  We love Root Rally, which is a blend of bone meal and Endo/Ecto mycorrhizae spores and plant nutrients, providing mycorrhizae life support for all plants.  (See more on mycorrhizae, below.)  Refill the hole and water well. 

See Eve’s ideas for ways and places to use bulbs that you may not have thought of!

Peruse our complete list of 2019 bulbs and individual images and descriptions 

Monarda didyma ‘Jacob Cline’

Planting perennials, roses, shrubs and trees:  The fall is a great time to plant perennials, roses and shrubs as they can focus solely on root growth instead of trying to reproduce.  After gently removing its pot, gently swish the root ball in a bucket of unchlorinated water with water-soluble mycorrhizae  (let the water sit overnight to release chlorine and add the mycorrhizae later).   Mycorrhizae is a beneficial fungi that attaches to roots, allowing them to better absorb water and nutrients.  This results in faster plant and root growth, and better transplanting success.  If you only have granular mycorrhizae on-hand, sprinkle it on the roots as you are planting.  Read more about mycorrhizae in Mikl’s article, “Mycorrhizae: The Hidden Marriage of Plants and Fungi”.

By gently swishing the root ball in water, the root mass will loose its pot-shape and individual roots will be lengthened.  This allows the ends of the roots to be planted deeper, helping to ensure long-term drought hardiness. 

After late-season planting, be sure to (hand) water deeply and frequently, at least twice a month for woody plants, throughout the winter. 

For specific info on rose planting, see Eve’s rose planting instructions.

Zauschneria garrettii ‘Orange Carpet’

Finally, a quick additional word on garden clean-up.  Some of our Southwestern plants should not yet be cut-back.  Wait until April to do so, which will give them additional time to gather and store nutrients, and keep the crowns of the plants from getting too cold. These plants include, but aren’t limited to, Agastache, Salvia  (S. lemmonii ‘Desert Rose’, S. reptans, S. x microphyllus ‘Royal Ruby’, S. greggii ‘Furman’s Red’, S. darcyi), Zauschneria (Hummingbird Trumpet), Scrophularia macrantha (Red Birds in a Tree), Scutellaria suffrutescens (Cherry Skullcap), Gaura lindheimeri.

Flood Recovery for the Garden

Flood recovery is not a problem most of us have had to deal with before so we can only try to solve the problems individually and make adjustments in the future.

The main problems seem to be:

1) Soil washed away-erosion

2) Soil dumped on top of plants, trees and existing soil

3) Plants washed away

4) Weed seeds deposited on the soil 5) manure and sewage and unknown contaminants deposited on the land[Read More]

Goldflame Spirea (Spiraea bumalda ‘Goldflame’)

Here’s a shrub that won’t grow over the living room windows, spread half-way across the driveway or send suckers up in the perennial border. It stays a compact 2’-3’ high and a little wider. It’s name comes from its spring leaf coloration which begins a russet or bronze-red mixed with yellow, changing to yellow-green and then green. The flowers are pinkish and bloom for a long time. Then again in the fall the spring leaf colors return to a golden copper-orange. This variety is very heat tolerant and has been successful in my xeriscape garden for 7-8 years. Occasional winter dieback has been slight and easily sheared off with hedge clippers. I also use the hedge clippers to remove the spent flowers after blooming.[Read More]

Geraniums for Sun or Dry Shade

Hardy Geraniums are in general very serviceable and these four have been very useful and successful for me. They are tolerant of diverse and adverse conditions and are especially useful in dreaded dry shade.[Read More]

Groundcovers Project in its 18th Year

In 1993 I sent a survey to 29 local horticulturists to get their suggestions on the best groundcovers for a demonstration project we were planning at Harlequin’s Gardens. I asked them to list 5-10 groundcovers that could be used to replace bluegrass in low traffic areas, that would need a quarter to a half the water of bluegrass, have few pests and diseases, would grow densely to limit weeds, would look good in most seasons and would not be invasive in gardens. The survey was typed on a typewriter and most of the replies were hand-written. People did drive cars back then. But that was a long time ago and I had a lot to learn.[Read More]

Hardy Geraniums

Hardy Geraniums are one of most versatile an adaptable perennials for our area. Available in many colors and habits, they can be useful in sun and shade, moist and dry, as a single specimen, as companion plants and as ground covers. These are not to be confused with the Pelargoniums which are the house plant, container and bedding plant “geraniums” which are not hardy outdoor plants in Colorado. The name “geranium” is derived from a Greek word meaning little crane, hens the common name “cranesbill” which refers to the appearance of the seed heads. The majority of the species of geraniums are native to the northern and mountain regions of Eurasia and North and South America although some are found in South Africa, India, Indonesia etc. Most grow in grasslands, meadows, roadsides and open woodlands. Therefore the natural habitat for most hardy geraniums seems to be sunny and moist or part-shade and moist or dry.[Read More]

Heat-Tolerant Plants

Most of our native plains plants and shrubs including:

Sumacs
Penstemons
Rabbitbrushes
Desert Four O’Clock
Saltbrush
Heterotheca
Artemisias (Sages)
Thelesperma
Gambel Oak
Sulfur Flower (Eriogonums)[Read More]

Lavandula – The Lavenders

Lavenders are great xeriscape perennials for Colorado, which bloom in the heat and dry of July and August. They are native to the rocky hillsides of the Mediterranean region. Here as well, they like good drainage, full sun, our alkaline soil and dry, loamy humus. Lavenders are aromatic herbs with gray foliage, the leaves as well as the flowers being strongly fragrant.[Read More]