Tag Archives: perennials

How’s Your Pruning Technique?

Cut ornamental grasses back as new growth emerges. Otherwise, you’ll end up with new growth poking out of dead blades, the wrath-of-God look.

As new growth emerges, our fingers often itch to get out in the garden.  Late February/early March is an ideal time to start cutting back ornamental grasses. With perennials, early to mid-March is a good time to prune.

Trimming ornamental grasses is simple, unless you have a huge stand of pampas grass or some such.  For small grasses, such as blue avena, simply use pruners or small hedge clippers to cut the blades down to 4-6 inches above ground.  For larger grasses, wrap a bungee cord or rope around the plant to contain the blades like a pony tail, then use manual or powered hedge clippers or a chain saw below the pony tail to cut the grass back to 6 inches or lower.  Once done, you can simply carry the rubble to your compost pile and remove the bungee cord or rope.  Be sure to wear gloves to avoid cuts.

Make quick work of pruning agastache and other spiky plants by wrapping a bungee cord around the base, then cutting the stalks below the cord.

As for perennials, you can prune them different ways, depending on the individual variety.  For some plants, such as soapwort, it’s often easiest to simply grab a handful of foliage, twist it, and yank it out.  Before you do this forcefully, however, give the plant a gentle tug to make sure you won’t be ripping it out of the ground when pulling on it.  But if you end up ripping out a small, rooted chunk of the plant, you may be able to transplant it elsewhere.

With orange carpet hummingbird and other short plants with stiff dormant twigs, you can often grab a handful of twigs and snap them off.

For taller, stalky perennials such as agastache, you may find it easiest to treat them like a large ornamental grass, wrapping a bungee cord around the stalks before cutting below with hedge clippers.

Otherwise, you can simply cut perennials to the ground with pruners, although it sometimes takes longer than some of the methods mentioned above.

You can prune many shrubs and trees this time of year, as well, using techniques from Colorado State University Extension.

Leave your roses alone, though.  Don’t prune them until late April or early May.  Otherwise, frost might kill new growth that occurs when pruning stimulates roses’ hormones.  For more information on roses, check CSU Extension’s Pruning Roses.

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Reseed Your Way to a Lusher Garden


Agastaches, such as Sonoran sunset (left) and sunset hyssop, reseed in some gardens, but not in others. The seedlings seem to spread more prolifically on bare ground or in sparsely mulched areas.

Do you have what it takes to grow self-seeding plants? Maybe, if you don’t mind seedlings popping up here and there, and you have the guts to destroy plants that turn thuggish. Because let’s face it–reseeders aren’t for everyone.

But for budget-conscious gardeners, self-sowing can offer an inexpensive way to fill gaps in a garden or cover large chunks of real estate in a hurry.

Let’s say you want to create a cottage garden in your back yard, but you’re concerned that self-sowers will crowd out your existing plants. You can select gently reseeding annuals and perennials.

The trick to successful reseeding is being able to recognize seedlings so you don’t mistake them for weeds and kill them. Study the leaf structure of mature plants, then compare it to that of the seedlings. The seedlings with long, slender leaves on the right and in the rear are sunset agastache. The plants to the left, with broader leaves, are Sonoran sunset agastache. Notice the tiny plant just sprouting at the far right? It’s another Sonoran sunset agastache.

Well-behaved annuals include sunflowers, pansies and sweet alyssum. As for polite perennials, consider low-growing bloody cranesbill with its bright fuchsia blooms; lady’s mantle with its fluffy lime-green clusters; or cupid’s dart with its purplish-blue flowers resembling bachelor buttons. You can also choose English lavender, bleeding heart, lupine, purple coneflower, chocolate flower, penstemon or agastache, as well as biennial snapdragon.

If you’re more interested in populating a large, sun-scorched area to prevent weeds, pick seedy characters that spread quickly. Aggressive annuals, such as California poppies, larkspur, bachelor buttons, cosmos and blue flax will sprout in your yard for years to come. You can also toss in a few strong-willed perennials, such as hardy four o’clock, with its deep-pink trumpet-shaped blooms and mint-green leaves; globe thistle with its architectural growth habit and spiky blue flowers; and knautia with its burgundy, pincushion-shaped flowers on long stems.

Broadleaf weeds or desirable perennials? These are baby soapworts, which can spread 24 to 36 inches wide and produce masses of pink flowers in spring.

Other quick spreaders include prairie winecups, Jupiter’s beard, Mount Atlas daisy, catmint, yarrow, hollyhock, rose campion, soapwort, and salvias such as May night. And don’t forget ornamental grasses, such as Mexican feather grass and little bluestem.

In the vegetable garden, lettuce is notorious for producing babies if you allow the plant to go to seed. You may also find volunteer tomatoes, spinach and purple mustard.

Check around your compost pile, too, for baby cantaloupes and other squashes that may have sprouted from seeds of decomposed parent plants. You’ll need to protect these little ones from the cold in early spring, but you can transplant them to your garden once the weather warms up.

Chives, both common and garlic, can reseed to the point of weediness in the garden. So can dill. Other self-sowing herbs are culinary sage, cilantro, some sorrels, catnip, oregano, borage, calendula, parsley and chamomile.

If you eventually discover that you have too much of a good thing, you can discourage reseeding by deadheading or yanking plants before they go to seed.

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Rabbit Resistant or Not? The Poop on 10 Perennials

Rabbits stayed away from Sonoran sunset hyssop in my garden. In general, they don't like hyssops. (Photo courtesy of Plant Select)

Rabbits stayed away from Sonoran sunset hyssop in my garden. In general, they don’t like hyssops. (Photo courtesy of Plant Select)

When I re-landscaped my front yard last September, I carefully researched lists of rabbit-resistant plants. I already knew that the plants I selected would, for the most part, be hardy and drought-resistant because I had grown several of them successfully in my old garden in Denver.

However, I didn’t have problems with rabbits in Denver. So I didn’t know which plants would really hold up against rabbit munching in my new Fort Collins landscape.

Here’s what I’ve discovered after planting the 10 perennials mentioned below.

Rabbit Food

Narbonne Blue Flax (Linum narbonense). Plant Select introduced this lovely selection in 2013, and I was eager to try it out. Narbonne reportedly has larger blooms, a fuller growth habit and a longer life that its better-known cousin, Colorado native blue flax (Linum lewisii). Unfortunately, rabbits sheared this plant to the ground within 24 hours of installation. So I may have to substitute either Linum lewisii or blue avena grass (Helictotrichon sempervirens) for a spot of blue in that part of the garden.

Orange Carpet Hummingbird (Zauschneria garrettii). It’s difficult to miss orange carpet hummingbird in a garden because of its neon orange, tubular blooms. This long-blooming, creeping Plant Select groundcover grows about six inches high and 18 inches wide. Surprisingly, the rabbits nibbled on this plant some, but didn’t eat it all the way to the ground, except on one occasion. So I think it stands a decent chance in the garden, especially because it spreads fairly easily.

Veronica (V. prostrata and V. pectinata). These two low-growing groundcovers have graced my gardens for the past 10 years or so. Because they’re evergreen, they provide an attractive organic mulch under late winter- and early spring-blooming bulbs. Then they produce their own show by carpeting the ground with small blue flowers in late spring or early summer. Unfortunately, the rabbits have taken a liking to some of the plants. I’m not giving up on veronicas yet, though, especially because they spread rapidly and may be able to outdistance the rabbits’ appetites.

Rabbit Resistant

Hidcote Lavender (Lavandula angustifolia ‘Hidcote’). I wouldn’t have a garden without lavender. It’s fragrant and evergreen, and on top of that, it produces delightful violet blue blooms. Hidcote grows about 16 inches tall and will spread as wide as two feet over time. After a few years, Hidcote will even begin producing babies that you can transplant around the garden. Munstead lavender is about the same size as Hidcote, but I prefer Hidcote because its leaves are softer-looking than Munstead’s are.  The rabbits haven’t touched my Hidcotes.

This mojave sage isn't rabbit food. Although the foliage looks green in this photo, the leaves are actually a soft blue in my garden. (Photo courtesy of Plant Select)

This mojave sage isn’t rabbit food. Although the foliage looks green in this photo, the leaves are actually a soft blue in my garden. (Photo courtesy of Plant Select)

Mojave Sage (Salvia pachyphylla). A friend of mine raved about this plant so enthusiastically that I decided to try it. I love it already, even though it hasn’t bloomed for me yet. Its leaves are a soft blue color that complement the fuchsias, oranges and purples in my garden. This Plant Select winner, which grows about three feet high and wide, has a shrubby growth habit. Mojave is a showy bloomer that produces violet-blue flowers surrounded by mauve bracts. Although my Mojaves sit close to hedge cotoneasters that provide cover for rabbits, the critters haven’t bothered these sages.

Rozanne Cranesbill (Geranium ‘Rozanne’). Five of these loose-growing groundcover plants went under my autumn brilliance serviceberry. The geranium’s purple blooms brighten the garden from early summer to frost. Rozanne grows about one foot high and three feet wide. The rabbits left these plants alone.

Sonoran Sunset Hyssop (Agastache cana ‘Sinning’ Sonoran Sunset). This compact show-stopper produces fuchsia blooms on upright stems from late summer to through fall. One of my plants was still trying to produce blooms well after frost, and all five were still producing basal foliage in early winter. A Plant Select winner, Sonoran Sunset grows about 15 inches tall and 18 inches wide. The rabbits didn’t go near it.

Sunset Hyssop (Agastache rupestre ‘Sunset’). This Southwestern native is another show-stopper with its smoky orange flowers emerging from lavender calyxes. Sunset can grow up to 42 inches tall and 18 inches wide. The rabbits didn’t like it.

Soapwort (Saponaria ocymoides). This humble workhorse is one of my favorite groundcovers. It’s evergreen, and it produces white or pink flowers that attract pollinators. I placed it along a path in front of my house to serve as a mulch between pavers. In bloom, soapwort reaches a height of about four inches. The rest of the time, this stalwart hugs the ground. Soapwort looks like a plant that rabbits would savor, but they didn’t.

Color Guard Yucca (Yucca filamentosa ‘Color Guard’). As an experiment, I installed two of these bad boys near my front porch for drama. I’ll install a third as soon as one of my existing plants produces babies, which should be soon if these plants make it through the winter. During the growing season, the plant’s spiky yellow-and-green leaves provide excitement on their own. But when Color Guard sends up stems that are three to four feet tall and produces panicles of stunning white flowers, you really begin to appreciate its architectural grandeur. Color Guard is evergreen, but in Colorado, it’s a raggedy evergreen that makes you wish the plant would just dormant altogether. The rabbits have wanted nothing to do with Color Guard.

That’s the news so far on my new perennials and their relationships with rabbits.

In another experiment, I also installed three blue panda corydalis (Corydalis flexuosa ‘Blue Panda’) bulbs for their lacy leaves and early spring blooms. Rabbits have nibbled on them some, but it doesn’t look as though blue pandas are among their favorites.

Happy New Year. May your gardening efforts be wildly successful in 2016.


Filed under Landscape Design, Plant Geekiness

Are ‘Bullet-Proof Plants’ Really Bullet-Proof?

A tiger eyes sumac, similar to the baby shown here, will be the centerpiece of my new garden.

A tiger eyes sumac, similar to the baby shown here, will be the centerpiece of my new garden.

Snow currently shrouds the carefully selected plants in my newly landscaped front yard. Bunnies have been chomping on some plants, even on so-called rabbit-resistant ones. I’m curious to see which plants survive the wildlife assaults and Fort Collins’ harsh winters to prove that they are, indeed, bullet-proof.

As promised in last month’s post, I’m sharing my plant selections with you, in case you’re looking for plants for tough growing conditions.


Autumn brilliance serviceberry (Amelanchier x grandiflora ‘Autumn Brilliance’).This multi-stemmed beauty is one of my all-time favorites, with its white spring blooms, tasty blue berries and flaming red-orange fall color. I wouldn’t have a garden without it.


Cheyenne Mockorange (Philadelphus lewisii ‘Cheyenne’). Cheyenne produces fragrant, lush white flowers each spring. This stalwart anchors a front corner of my house and will eventually reach 6 to 8 feet tall and 5 to 8 feet wide.

Hedge Cotoneaster (Cotoneaster lucidus). The home’s previous owner installed two of these shrubs, which turn an eye-popping red each fall. The shrubs are currently overgrown, but I’ll cut them to the ground this winter so they’ll emerge at a more appropriate size.

Pawnee Buttes Sand Cherry (Prunus besseyi ‘Pawnee Buttes’). I installed this woody groundcover for its hardiness, white flowers and red fall foliage. It’ll grow about 18 inches tall and 6 feet wide. The thing is, rabbits like to munch on Pawnee Buttes’ new shoots, so I’ve placed protective cages around these plants for the time being.

Regent Serviceberry ( Amelanchier x ‘Regent’). Like its cousin autumn brilliance, regent serviceberry boasts spectacular fall color. But instead of red, regent shows off stunning golden-coral autumn color. Regent also has a more compact and delicate growth habit than autumn brilliance. This colonizing shrub is a slow grower that will eventually stretch 6 feet high, but it can easily be pruned to a lower height.

Tiger Eyes Sumac (Rhus typhina ‘Bailtiger’). I’ve had my eye on this stunner for years, and finally I have a spot for it in the garden. Tiger Eyes is the centerpiece of my landscape because it’s so showy. Unlike other sumacs, Tiger Eyes doesn’t sucker insanely in Colorado unless it’s installed in heavily amended soil. I dug a circle 3-foot circle around it and shoveled in lean clay soil to discourage suckering. The shrub has lacy yellow and chartreuse foliage on rosy pink branches. Each fall, the leaves turn orange-red. Don’t over-water this baby. Right now, it’s an ugly brown fuzzy stick with buds on it. But as it matures, it will keep its branches over the winter to provide architectural interest.

Angela sedum? It's drought-tolerant and beautiful, but rabbits ate mine to the ground.  Try lemon coral sedum instead.

Angela sedum? It’s drought-tolerant and beautiful, but rabbits ate mine to the ground. Try lemon coral sedum instead.


Angelina Sedum (Sedum rupestre ‘Angelina’). Rabbits decimated this yellow/chartreuse groundcover as soon as I plunked it in the ground. So I took the crumbs from their feast and planted them elsewhere in the garden. The crumbs have taken root. But I’m concerned about this plant’s long-term survival with so many rabbits around. Last spring, Proven Winners sent me some new plants to try. One of them was lemon coral sedum (Sedum reflexum ‘Lemon Coral’), a splashy, tough Angelina sedum look-alike that stands three inches high. The rabbits never touched lemon coral. Unfortunately, this new plant is an annual in Colorado, but I’m hoping that lemon coral self-sows so that more of this wonderful plant will emerge next spring.  You’ll find lemon coral in garden centers next spring.

Valentine Bleeding Heart (Dicentra spectabilis ‘Valentine’). This newer, more compact variety of the traditional bleeding heart is a show-stopper. It will grow about 2 feet tall and wide with lovely reddish-pink flowers and the usual, attractive, deep-cut foliage. Rabbits nibbled on the bleeding hearts some, but not a lot. I’m hoping that, unlike the traditional bleeding heart, valentine will resist going dormant in mid-summer.

There are 10 more perennials in my garden. I’ll describe them in my next post.

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