Cultivate Low-Water Lushness with Drought-Tolerant Groundcovers

Soapwort flows past a boulder where Steve, my tabby, acts as overseer. Directly behind Steve, you can see bonfire euphorbia just starting to bloom with bits of yellow bracts showing. To the left of the soapwort sits Pawnee Buttes sand cherry, and in the center of the background is orange carpet hummingbird, which will burst forth with neon orange flowers in the next week or two.

While traveling through Louisiana years ago, I was amazed by the sheer lushness of the trees, grass and flowers.

Here in Colorado, I rarely spot lush residential landscapes.  What can you expect in such an arid climate?  All the same, I love luxuriant gardens in which plants simply flow into each other.

Most trees and shrubs, by their very nature, offer a degree of lushness, which is why homeowners love them.  But groundcovers can add a whole new level of richness.

I’ve been experimenting with various low-water groundcovers to create a sense of lushness in my Fort Collins landscape.  It has taken about four years to get close to achieving the sumptuousness I’m looking for, but I’m making progress.  I’ve propagated new plants from existing ones to keep costs down.

My goal has been to provide successional bloom; in other words, have something new flowering throughout the season for aesthetics and for pollinators.

Here are plants I’ve used successfully.

Spring bloomers

Woolly speedwell (Veronica pectinata).  One of my all-time favorites, woolly speedwell offers an evergreen carpet for flowering bulbs in early spring.  Then around April or May, small blue blossoms emerge on this ground hugger, creating a spectacle of color that lasts for three or four weeks.  Although drought tolerant, woolly speedwell performs best in part shade with regular watering.   To propagate it, dig up a chunk and move it where you need it.

Bloody cranesbill is one of the toughest groundcovers I’ve ever grown. It thrives in both sun and shade, offering a flush of bright fuchsia flowers in the spring.

Soapwort (Saponaria ocymoides).  This sun-loving, evergreen beauty begins blooming in late spring and continues into early summer with a profusion of perky pink flowers.  There’s a white-flowered soapwort, as well.  Soapwort reseeds prolifically, covering a significant amount of real estate in a short time.  Many web sites claim that soapwort spreads 15 to 18 inches.  Don’t believe it.  Some of my pink bloomers routinely grow 40 inches wide and eight inches high.  If you want to discourage soapwort’s spread, simply pull off the seed heads.

Candytuft (Iberis sempervirens).  Candytuft resembles a wedding bouquet with its profusion of white blooms.  The plant’s attractive deep green leaves keep their color year-round.  This underused plant begins flowering in late spring and extends well into June.  Candytuft will grow about two feet wide.  You can divide it for more plants.

Summer bloomers

Bloody cranesbill (Geranium sanguineum).  An early summer bloomer, bloody cranesbill produces bright fuchsia blooms in both sun and shade.  After its initial flush of flowers, this groundcover will continue to produce occasional blooms throughout the growing season.  It grows about 14 inches high and 36 inches wide, and is extremely drought-tolerant.  Propagate it by division.

Rozanne cranesbill (Geranium ‘Gerwat’ Rozanne).  Rozanne is Bloody’s cousin with bigger, longer-lasting blooms.  In my garden, Rozanne grows about 20 inches high and 36 inches wide, and explodes with two-inch-wide purple blossoms from June till September.  Like bloody cranesbill, Rozanne will grow in both sun and shade, and can be propagated by division.  Although drought-tolerant, Rozanne prefers regular watering.

Sumptuous Rozanne cranesbill provides purple blooms from June till September.

Prairie winecups (Callirhoe involucrata).  This hardy groundcover sends out 30-inch runners loaded with rich magenta goblet-shaped blooms.  Winecups begins blossoming in late May and keeps on going till frost.  The easiest way to propagate prairie winecups is by seed.

Bonfire euphorbia (Euphorbia epithymoides ‘Bonfire’).  I’ve loved this mounding plant ever since spotting it at the Colorado State University perennial trial garden years ago.  Its showy red/orange/purple foliage makes this plant a show-stopper throughout the growing season.  But when it blooms, whoa Mama!  Bonfire’s brilliant yellow bracts grab the attention of passers-by, who often pause and ask questions about the plant.  Although often described as a groundcover that grows 18 inches wide, my four-year-old bonfire is 30 inches wide and 14 inches high.

Meidiland groundcover roses perform spectacularly in the garden, especially in hot, dry areas. This fire meidiland, with its double blooms, is a show-stopper.

Groundcover roses.  My favorite groundcover roses are the meidilands, which come in red, pink, yellow and white.  These ground-hugging, weed-squelching stalwarts thrive in the hottest, driest growing conditions and feature stunning, deeply colored blooms.  I favor fire meidiland, in particular, with its lush double blooms, but have also grown red meidiland successfully.  Another delightful groundcover rose is seafoam, a white variety that grows in the White House rose garden.  My only caveat with white roses is that they’ll turn brown if you grow them in sun that’s too intense.  The roses bloom from June till frost.  Groundcover roses are easy to propagate by simple layering.

Hardy plumbago (Ceratostigma plumbaginoides).  This gorgeous plant will grow in sun or shade.  I like growing it under trees.  It’s drought tolerant, but grows best with regular watering.  In July, plumbago delivers striking gentian blue flowers, followed by lovely copper-colored seed heads.  Then in the fall, the foliage turns red.  Plumbago spreads readily by itself, but you can encourage it by digging up a chunk to plant where you need it.

Fall bloomers

Except for bloody cranesbill and bonfire euphorbia, all of the summer bloomers mentioned above continue flowering through the fall.  Another summer/fall bloomer is orange carpet hummingbird (Zauschneria garrettii).

Groundcovers act as organic mulches that save you time and money you might otherwise spend on wood and rock mulches.  If you haven’t used groundcovers on a large scale, I encourage you to try them.

 

 

Advertisements

Leave a comment

Filed under Landscape Design, Plant Geekiness

Chihuly on View at Kew

Chihuly’s iconic Summer Sun brightens the walkway in front of the Palm House at Kew Gardens.

During a visit to Kew Gardens near London earlier this month, I was delighted to discover a Reflections on Nature exhibit by renowned American glass artist Dale Chihuly.

Some pieces, such as the iconic Summer Sun and Red Reeds, appeared at Denver Botanic Gardens in 2014.  Those and other familiar pieces showed up at Kew, as well, along with other, newer pieces.

Besides displaying Chihuly’s work among plants, Kew Gardens presented an extensive variety of additional works in its Shirley Sherwood Gallery.

The show runs from April 13 to October 27, 2019.

Chihuly expertly weaves his Green Hornets and Gold Waterdrops sculptures among palm fronds in Kew’s Temperate House.

Blossom-shaped bowls delight visitors at Kew Gardens’ Shirley Sherwood Gallery.

 

Leave a comment

Filed under Landscape Design, Whimsy

How to Start a Strawberry Patch on The Cheap

Bare root strawberries sit in a pot in my garage, where they wait until early April, when it’s warm enough to plant them outdoors.

Who doesn’t love strawberries?  Those plump, juicy little chunks of goodness snatch our attention when we spot them in grocery stores.

Fortunately, strawberries are easy to grow in Colorado gardens.  All you have to do is clear a patch of land and amend the soil with compost before plunking those babies into the ground.

The least expensive way to start a strawberry patch is to buy bare root strawberries online or at your local nursery.  Early April is the best time to install bare root plants in gardens along Colorado’s Front Range.

I use golf tees to mark locations for the plants. Everbearing plants produce fewer runners than June-bearing plants, so I plant them 5 inches apart in rows that are 18 inches apart. Eventually, I’ll cut off the babies on runners and use them to expand my strawberry patch.

I buy my bare root plants in early March for the best selection.  Then I soak them in water overnight before planting them in potting soil in a large pot, which I keep in the garage.  I keep them moist, but am careful not to overwater them because I don’t want them to rot.  Within a week or two, the plants start budding.  Then in early April, I place them in the ground while they’re still semi-dormant.  You can also simply buy bare root strawberries in April, soak them overnight, and plant them directly into the ground.

Another option is to go out and buy potted strawberry plants for planting in late May, but for the price of one or two potted plants, you can buy 10 bare root strawberries.

Before inserting a bare root strawberry into the ground, simply poke a slit into the soil with a garden trowel and then insert the plant, snugging the soil around it.

There are three basic classifications for strawberries:  June-bearing, everbearing and day neutral.  Although June-bearing plants produce the tastiest berries, their flowers can be damaged by late spring frosts, causing low yields.  For that reason, ever-bearing plants tend to be a better choice for Colorado gardens because ever-bearers produce crops in both summer and fall.  As for day-neutral varieties, they flower and fruit more consistently over the summer.  Interestingly, though, I haven’t seen any day-neutral varieties in local nurseries, which makes me wonder if day-neutrals are as winter-hardy as June-bearing and ever-bearing plants.

Some recommended June-bearing varieties for Colorado include Honeoye, Guardian, Kent and Delite.  I’ve grown Honeoye successfully, but haven’t tried the others.  Preferred ever-bearing varieties include Ogallala, Fort Laramie and Ozark Beauty.  I grew Ozark Beauty last year and am adding more, as well as Fort Laramie this year.

The literature I’ve read indicates that strawberries need full sun to grow best.  I’ve found, however, that mine do quite well in part shade, given the intensity of Colorado’s sun.

When you plant bareroot strawberries in the ground, you may need to trim the roots back to about four inches.  Be careful not to bury the crown or leave the roots exposed.

As for strawberry planting patterns and cultivation, the directions become rather wordy, so I’ll refer you to Colorado State University’s Strawberries for the Home Garden fact sheet and Cornell University’s Strawberries fact sheet.

Concerning mulching, I tried using straw mulch, as recommended.  However, the straw produced so many weeds that I ended up donating the straw to a more weed-tolerant gardener and began using grass clippings instead.  This year, I’ll try putting down a couple of layers of newspaper (no colored inks) and leftover packing paper, holding them down with rocks until I accumulate enough grass clippings to anchor the paper.

In addition to providing fruit, strawberries function well as a groundcover to help keep weeds out of your perennial beds.

If you start growing strawberries, you may enjoy them so much that you’ll decide to branch out into other berries, such as Chester dwarf blackberries.

Leave a comment

Filed under Produce Dept.

Kick-Ass Plants for Badass Territory

Kick-ass plants can provide color and interest even when they’re not in bloom. In this fall landscape, you’ll see (clockwise from lower left) Genista lydia, fiery Pawnee Buttes sand cherry, Sonoran sunset hyssop, sunset hyssop, blue avena grass, and orange carpet hummingbird.

Unless you’re one of those rare Colorado gardeners with a shady yard, you probably have spots that get blasted by the sun—in other words, badass areas.  And you likely have heavy clay soil, too.

The southwest corner of my front yard is badass.  Besides getting hammered by western and southern sun, the area sits next to a sidewalk, which radiates heat.

So when I designed this space, I selected kick-ass, drought-tolerant plants with fall color and winter interest in mind.  I also wanted most, if not all, of the plants to attract pollinators.  Here are the plants that made the cut.

Around July, these kick-ass plants burst with color, particularly the fuchsia-colored Sonoran sunset hyssop, salmon-and-lavender sunset hyssop, and neon orange carpet hummingbird. The Genista lydia in front erupts in electric yellow flowers in the spring. Pawnee Buttes sand cherry, behind the genista, produces white flowers in the spring. Because of their successional bloom, the plants (other than the blue avena grass) provide nectar to pollinators throughout the growing season.

Lydia broom (Genista lydia). This evergreen, groundcover shrub explodes with electric yellow flowers in the spring.  Its branches are somewhat scruffy, which is probably why you can’t find it in nurseries these days.  However, there’s a new smaller cultivar with more attractive branching:  Lydia bangle broom (Genista lydia ‘Select’).  Bangle grows 12-24 inches high and 18-24 inches wide, and produces the same showy yellow flowers that Genista lydia   I haven’t seen this plant in Fort Collins nurseries yet, but The Tree Farm in Longmont sells it.  So I’m guessing this cultivar will migrate north to local nurseries before long.

Pawnee Buttes sand cherry (Prunus besseyi). In April, this low-growing shrub pumps out fragrant white flowers, followed by black berries in the summer.  In the fall, this plant’s foliage is pure magic, when sunlight catches its fiery red leaves.  Then in winter, Pawnee Buttes’ perky little branches stand at attention.  This shrubby ground cover will reach 15-18 inches high and 4-6 feet wide.  Don’t let its width scare you, though.  Pawnee Buttes responds very well to pruning if you want to keep its width at four feet or so.

Sonoran Sunset hyssop (Agastache cana ‘Sinning’). This herbaceous, woody-based perennial blooms prolifically with fuchsia flowers from early June through October.  Then in late fall, its blooms turn tan, providing winter interest.  Pollinators, especially hummingbirds, love it.  Sonoran Sunset grows 15-18 inches high and 12-15 inches wide.  If you have heavy clay soil, be sure to amend it with compost to improve drainage.  Once this plant is established, don’t overwater it.  I’ve killed a couple that way in a moister part of my yard.

Sunset hyssop (Agastache rupestris). Sunset hyssop features salmon-and-lavender blooms.  It’s taller than Sonoran, reaching 2-4 feet high by 20-30 inches wide.  So I plant it as a backdrop to Sonoran.  Agastache has a reputation for being a short-loved perennial, but all of my sunset hyssops are going into their fourth season.

Orange carpet hummingbird (Zauschneria garrettii). As the common name suggests, this plant is beloved by hummingbirds for its tubular, neon-orange blooms from June to October.  Zauschneria spreads quickly and grows 3-4 inches high by 15-20 wide.  It’s one of those plants you’ll be able to share with neighbors.

Blue oat grass (Helictotrichon sempervirens). It’s not easy to find blue plants for a garden’s color scheme.  That’s one reason I like blue oat (avena) grass so much.  Unlike many ornamental grasses, blue oat grass, doesn’t reseed and take over your yard.  This well-behaved plant delivers arching stalks of airy plumes in early summer, and grows about 2-3 feet high and wide.  This is the only plant in my badass area that doesn’t provide nectar for pollinators.

Cut the hyssops and blue oat grass to the ground in March or April as new growth emerges.

All of these plants offer nearly year-round interest except for orange carpet hummingbird, which dies back in winter.  They also bloom at different times so that pollinators have food sources throughout the growing season.

On April 14, I’ll be offering two short programs on kick-ass plants at the Sustainable Lifestyle Expo at the FirstBank Center in Broomfield, Colorado.  Colorado State University Extension agents, specialists and volunteers will provide research-based demonstrations and talks on more than 30 topics. Expo tickets are $10 for adults.  Admission is free for ages 17 and under.

Leave a comment

Filed under Landscape Design, Plant Geekiness, Shameless Plugs

Keep Your Flowers Fresher Longer

What’s the #1 longest-lasting cut flower? Zinnia. These pollinator-attracting plants reach about 1 to 4 feet tall and are available in many colors.

With Valentine’s day approaching, many of you may find yourselves with bouquets of fresh flowers.  And others of you may be cutting flowers from your gardens later this year.

Either way, you’ll want to keep those flowers fresh as long as you can.

Guess what’s the most effective method for keeping these lovelies in pristine condition.  Pennies?  No.  Bleach? Unh-unh.  Aspirin, hairspray, vodka, vinegar with sugar?  Not even close.

ProFlowers, the online florist, tested all of the methods above and then some.  The test results indicated these two methods work best:  One, refrigerate your flowers each night; and two, add ¼ cup of soda pop (preferably clear, such as 7-Up) to the vase water.  This reportedly works even better than flower food.

If you pick the flowers yourself, be sure to cut them with a sharp knife or bypass pruners in the morning or early evening rather than during the mid-day heat.  Then insert the stems in clean water right away.

Roses, such as the Fire Meidilands shown here, are stunning in cut-flower arrangements.

Whether you receive flowers as a gift or harvest them yourself, cut the stems at an angle for better water absorption, and remove all leaves below the water line to minimize bacterial growth.

Opinions vary concerning water temperature, but most sources recommend lukewarm water in the vase.  Add more water as needed, and clean the vase every few days.

Keep the flowers away from full sun, fruit, and hot and cold drafts.

Among the longest-lasting cutting flowers are zinnias, carnations, alstroemerias, delphiniums, daisies, peonies and sunflowers.  So plant your garden accordingly for bountiful blooms and durable arrangements.

 

Leave a comment

Filed under Plant Geekiness, Whimsy

Unsung Heroes Brighten Winter Landscape

Japanese barberry feeds birds and the soul with its colorful winter berries.

Easy-to-grow plants with winter interest are Japanese barberry, Angelina sedum, creeping and upright Mahonia, color guard yucca, and ornamental grasses.

Yes, I know Japanese barberry (Berberis thunbergii) is somewhat overplanted in Colorado.  But there’s a reason for that.  This sun-loving shrub is extremely hardy.  The birds love the berries, especially in winter.  And people love the berries for their brilliant red color, especially in an otherwise-drab winter landscape.  The Kobold variety even resembles boxwood—a plus for gardeners who love the look of boxwood but don’t want to deal with its inherent problems in Colorado.

Angelina sedum explodes with yellow, orange-red, purple and green foliage in the winter.   This indestructible plant will gradually spread, and babies can be easily transplanted.  In warmer months, the foliage turns chartreuse.

Low-growing Angelina sedum generates explosions of color throughout the garden.

Mahonia aquifolium and Mahonia repens always have something going on.  They hold their leaves year-round, offering deep green foliage in warm months and reddish foliage in winter.  Each spring, Mahonia produces bright yellow flowers, followed by blue berries, which birds love.  Mahonia, like Japanese barberry, is tough and drought-tolerant, but grows best in shade.

Mahonia repens takes on subtle red hues when temperatures turn cold.

Color guard yucca displays yellow-and-green-striped leaves in warm weather.  When winter rolls around, the sword-like foliage becomes even more interesting by adding a bit of coral color to the yellow and green.  I’ve grown this non-patented beauty for about three years and have divided it to propagate three more plants.  The mother plant is 16 inches tall and 24 inches wide.  I’m hoping it’ll flower one of these years.

Hints of coral enhance Color Guard yucca’s yellow and green sword-like leaves in winter.

Ornamental grasses are stalwarts that provide architectural elements in the winter garden.  Don’t cut them back until late February or early March.

Other favorites for the winter garden are Harry Lauder’s walking stick, red twig and yellow twig dogwoods, yews, pines, firs, spruces, junipers and hawthorns.

Leave a comment

Filed under Landscape Design, Plant Geekiness, Whimsy

Low-Cost Propagation Methods Can Multiply Your Shrubs

This multi-caned red twig dogwood can be propagated by using simple layering, division, runners or stem cuttings.

In last month’s post, I explained how to use simple layering to propagate shrubs with branches close to the ground.

But what about shrubs that don’t have low-hanging branches?  Fortunately, there are other propagation approaches you can use: Dividing root balls, transplanting runners, and taking stem cuttings.  Within a short time, you can have several baby shrubs for transplanting around your yard.

Dividing root balls.  There are many shrubs that don’t respond well to division because of their tree-like growth habit from a single trunk.  But there are other shrubs, primarily those that produce multiple canes, that divide nicely.  Examples include butterfly bush, rose, dogwood, spirea, potentilla, lilac and forsythia.

To propagate by division, dig up the root ball of the mother plant.  The root ball may fall apart by itself, leaving several cane clumps with roots attached.  If not, use a shovel or knife to cut the ball apart, being careful to minimize damage.  Make sure that each cane clump has a good root ball.  Then transplant the clumps to their final resting places.

Transplanting runners.  Some shrubs produce runners, called rhizomes (underground) or stolons (above ground), which create suckers.   These shrubs are called colonizers because, over time, they’ll create colonies of themselves if left unchecked.  Colonizers include serviceberry, dogwood, lilac, sumac and kerria.

If you want to propagate and transplant a baby shrub from the mother shrub, look for a branch growing several inches from the mother plant—a branch that looks like it wants to strike out on its own.  Carefully dig around that branch to see whether it’s attached to its own runner.  If you spot a runner, dig it up, coat it with a rooting hormone, such as Clonex, and gently place it in a hole in a pot or in the ground.

If you’re using a pot, mix peat moss with sand or perlite for a loose, well-draining medium.  If you’re planting the runner in the ground, dig a trench about six inches deep and fill it with sand.  You should moisten your growing medium with water, then poke a hole in the medium with your finger so you can insert the runner into the medium without disturbing the rooting hormone.  Then gently backfill the hole.  After that, just keep the runner watered the same as you would a regular plant.

Then wait about four months or so to give the runner time to develop auxiliary roots before transplanting it to its new home.

Taking stem cuttings.  This approach, in my experience, is the diciest of the propagation methods.  So if you can propagate a shrub by layering, division or transplanting runners, I suggest that you use one of those methods instead of taking cuttings.

In spite of difficulties, I have successfully propagated red twig dogwoods from cuttings.  But my success rate was only about 60 percent. Professionals have better equipment and are far more adept at propagating from cuttings than I am.

With layering and division, I’ve had a 100-percent success rate, and with transplanting runners, I’ve averaged about 75%.

If you have your heart set on propagating a shrub that can’t be propagated with the other methods I’ve described, then cuttings are the way to go.

There are three types of woody plant cuttings:  softwood, semi-hardwood and hardwood.  Softwood cuttings are taken from tender new growth in the spring or early summer.  Semi-hardwood cuttings are taken from partially matured growth in the summer.  Hardwood cuttings are taken from mature stems during the fall and winter.

Different types of shrubs root more readily from different types of cuttings.  Daphne and euonymus, for example, propagate most readily from semi-hardwood cuttings.  Viburnum, on the other hand, propagates most readily from softwood and hardwood cuttings.

To determine which shrubs require which cutting types, I check my reference book, Plant Propagation from The American Horticultural Society.

When I propagated red twig dogwoods, I took semi-hardwood cuttings in late summer and stripped off all the leaves.  Then I dug a trench, filled it with sand, and planted the cuttings the same way I did for the runners mentioned earlier.  I then mulched the cuttings with black plastic.  The following spring, I planted the cuttings in their final resting places.  Four of my seven cuttings survived the winter and transplanting.  I used rooting hormone on three of the seven cuttings.

If you want to get serious about rooting shrubs from cuttings, I suggest consulting Plant Propagation for step-by-step instructions.

Leave a comment

Filed under Garden Maintenance, Plant Geekiness