Cheyenne Garden Gossip

Gardening on the high plains of southeastern Wyoming


Ground covers

2017-8 Sweet Woodruff by Barb GorgesPublished Aug. 13, 2017, in the Wyoming Tribune Eagle, “Covers of Color, ground covers good for replacing grass or gravel, and feeding bees”

By Barb Gorges

Gardeners consider ground covers to be short plants that act as living mulch, suppressing weeds and preventing erosion.

Your bluegrass lawn is a ground cover. Because it is so popular, its growing needs are well known. You can easily find someone to grow and mow it for you. Even simpler is growing native grasses—less water and much less mowing [search “Buffalograss” at www.CheyenneGardenGossip.wordpress.com].

However, when I surveyed the Laramie County Master Gardeners for their favorite perennial ground covers, a variety of short, flowering plants were listed requiring various amounts of sun and water.

All have big advantages over mulches like gravel or wood chips. Established ground covers out-compete weeds. Rock and wood chip mulches, on the other hand, eventually fill with weeds. Plants keep the ground around themselves cooler. Rock mulch makes an area hotter. Plants recycle carbon dioxide and make oxygen. Rocks and woodchips don’t.

A blooming ground cover offers more for bees and butterflies than rock, wood or a plain lawn. You can combine plant species in a mosaic, or in what’s being called a tapestry lawn by researchers at the University of Reading in Britain.

And you are in luck, late summer is a great time to find perennial ground covers on sale at local garden centers.

Plant now, a month or two before winter weather sets in, and you should see most of your investment sprout in the spring.

How close together you plant depends on how big a hurry you are in to get an area to fill in.

When comparing hardiness ratings, keep in mind Cheyenne is rated Zone 5, but many local gardeners look for hardier varieties rated down to the colder Zone 4 and even Zone 3.

Stonecrop, Sedum hybridum, is recommended by Catherine Wissner. There are many varieties of these succulents, but this one is only 4 inches high. It produces yellow flowers in late spring and early summer. It needs full sun, low amounts of water (after establishment) and is rated Zone 4.

Birdseye Speedwell, Veronica filiformis, is another of Wissner’s choices. This Zone 3 speedwell is only 2 inches tall. Fast growing, in some climates it can invade turf. Small blue flowers with white centers bloom mid-spring.

2017-08 Turkish Veronica Mary Ann Kamla

Turkish Veronica, by Mary Ann Kamla

Turkish Veronica (or Speedwell), Veronica liwanensis, is one of three kinds of ground covers Martha Mullikin grows between flagstones. They all do well because they get the extra moisture running off the stone. This Zone 4 perennial becomes a blue-flowered carpet 1 to 3 inches tall in spring. It prefers sun with afternoon shade and a drier situation. Linnie Cough said hers blooms for two months. It is a Plant Select variety developed by the Denver Botanic Gardens and Colorado State University for thriving in western gardens.

Woolly Speedwell, Veronica pectinata, is a favorite of Susan Carlson. It is like Turkish Veronica, but the leaves are silvery instead of glossy. Both stay green over the winter.

Woolly Thyme, Thymus lanuginosus, and Lemon Thyme, Thymus citriodorus, are the other two forming mats over the flagstones at Mullikin’s. Both are good to Zone 4. Both like full sun and do well in xeric (dry) conditions. Lemon Thyme has the added benefit of being considered a culinary herb.

Red Creeping Thyme, Thymus praecox ‘Coccineus,’ listed by Tava Collins, is a red-flowering ground cover that doesn’t mind being stepped on a little. A Zone 4, it is drought tolerant once it has been established.

Mullikin is enamored with Dianthus ‘Tiny Rubies,’ Dianthus gratianopolitanus, which forms a 2-inch tall mat of leaves covered in pink flowers mid-spring to mid-summer. It prefers full sun and doesn’t mind the colder temperatures of Zone 3.

Barren Strawberries, Waldsteinia ternata, will remind you of strawberries, but the small yellow flowers (Mullikin has a variety with pink flowers) produce fruit considered inedible by people—no word on whether squirrels like them. A Zone 4, it likes full sun to part shade, and is somewhat drought tolerant.

2017-08 Periwinkle by Barb Gorges

Periwinkle, by Barb Gorges

Small-leaved Periwinkle, Vinca minor, Kathy Shreve said, “can take shade, and will grow under a limbed-up spruce tree if given enough water.” A Zone 4 less than 4 inches high, its periwinkle-blue flowers show up in May and early June. Mine, despite being in deepest shade, still plots to take over the world so I prune it when necessary.

Sweet Woodruff, Galium odorata, is another that does well in shade (it doesn’t like full sun), but I think mine would do better if I watered it more—it might reach the listed height of 6 to 12 inches. A Zone 4, its tiny white, fragrant flowers show up in May. Tava Collins said when it is stepped on or cut (or mowed), you may get the sweet smell of hay.

Hummingbird Trumpet, Epilobium canum ssp garrettii ‘Orange Carpet’ also goes by Zauschneria garrettii. Shreve reports it is a “great xeric ground cover, does not seed around indiscriminately, and hummingbirds really do love the orangey-red flowers. Also, it blooms in late July-August when most everything else has pooped out.” This is precisely when migrating hummingbirds passing through Cheyenne would appreciate it. A Zone 3, it is also a Plant Select variety.

2017-08 Soapwort Saponaria Mary Ann Kamla

Soapwort, by Mary Ann Kamla

Mary Ann Kamla recommended several plants including Creeping Jenny, Lysimachia nummularia, a Zone 3 with yellow flowers mid-summer. Mildly invasive, she keeps it contained with the edge of the patio.

Another that is doing well for Kamla is Soapwort, Saponaria officinalis. A Zone 3 with pink to white flowers, it appreciates water. Its leaves have historically been boiled to make a bubbly liquid soap.

Tava Collins is a fan of Spotted Deadnettle, Lamium maculatum. She grows two varieties: ‘Purple Dragon’ and ‘Pink Chablis,’ the names describing the flower colors. Hers bloom throughout the season, Collins said. The leaves are silvery with green edges. These varieties are Zone 4, but some others aren’t as cold hardy. Cutting back will encourage new blooms. The bumblebees love Lamium, Collins said.

2017-08 Spotted Deadnettle by Barb Gorges

Spotted Deadnettle, by Barb Gorges

Also on Collins’ list: Black Scallop Bugleweed, Ajuga reptens ‘Black Scallop.’  Ajugas are good ground covers in general. This one has leaves that look nearly black when grown in full sun. Early summer it has blue flower spikes. A Zone 3, it can be invasive in the garden.

Richard Steele simply grows clover instead of grass. It’s mowable, takes less water, he says, and it feeds his bees, which provide him with honey.

There are two ground covers I planted this year that Shane Smith, Cheyenne Botanic Gardens director, mentions in his garden tips at www.botanic.org. One is Creeping Phlox, Phlox subulata. A Zone 3, it should have no problem coming back next year, but since it prefers sunnier spots, I’ll see if it its pink and white flowers will develop in the shade.

The other is Snow-in-Summer, Cerastium tomentosum, another Zone 3, with silvery green leaves. Maybe next year it will give me more than one white flower. Patience, patience. Growing perennials is a long-term investment

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Buffalograss: less water, fertilizer and work

Brent Lathrop, buffalo grass

Brent Lathrop’s buffalograss lawn is the perfect low water, low fertilizer, low work alternative for the High Plains. Photo by Barb Gorges.

Published March 22, 2015, in the Wyoming Tribune Eagle, “Rethinking your lawn? For less fertilizing, watering and mowing, try going native with buffalograss.”

By Barb Gorges

By the end of our long winter, our thoughts may turn to excuses to get outside, even working in the yard. But it doesn’t take very long before we remember the actual drudgery of lawn chores.

If you’d rather be fishing or biking or hiking or camping this summer instead of mowing, get a tip from Cheyenne resident Brent Lathrop: buffalograss.

Kentucky bluegrass is the default lawn in Cheyenne. However, I know half a dozen homeowners like Brent who have switched to a grass species native to our High Plains.

Last fall, I went to see Brent’s backyard, a swath of buffalograss. It was heading into dormancy, turning from green to the pale straw color of the winter prairie.

Because of the covenants in his neighborhood, his front lawn must be the conventional Kentucky bluegrass.

This is the fourth native lawn Brent has established, and the most difficult because of three droughty years at the beginning.

The backyard of his new house was raw dirt when Brent seeded it in 2006 with a mix of 90 percent buffalograss and 10 percent blue grama, another native grass. By 2011, the lawn was finally looking the way Brent wanted.

Choosing to go native is a natural choice for Brent. “It’s in my DNA because of what I do,” he said. He works for The Nature Conservancy as the program director for southeastern Wyoming. A low maintenance lawn, requiring less water, fertilizer and work, is a step towards more sustainable landscapes.

Once buffalograss is established, technically speaking, it doesn’t need irrigation, but Brent waters it a couple times in the spring to help it green up sooner, to cater to his neighbor’s lawn expectations.

Last year, Brent spent only $194 on lawn watering for the entire growing season, including back and front yards, while his neighbors reported spending more than that each month.

Buffalograss closeup

Because Brent used seed to establish his buffalograss lawn, seed heads develop. Buffalograss established by using plugs or sod is reproduced vegetatively with all female plants and no pollen is produced–a side benefit for people with allergies. Photo by Barb Gorges.

Only 3-4 inches tall, buffalograss could be left unmown, but once again, Brent considers his neighbors’ sensibilities and mowed six times last year, to keep it a little less ragged.

What he would really like to do is burn the grass. It evolved with fire and can get “decadent” without it, but figuring out how to do that in a residential neighborhood with yards bounded by plastic fences is problematic.

Buffalograss appreciates a little fertilizer. Brent fertilizes once a year, mid-June, at half the recommended amount. Not bagging his clippings when he mows also adds nutrients.

Weeds are not much of an issue. Brent digs any by hand. Besides that, in my research I discovered buffalograss is susceptible to some of the common weed killers.

He will need to deal with some Kentucky bluegrass invading from other yards. But he also encourages native wildflowers to grow, just as they would on the prairie.

One of Brent’s fringe benefits during the first years of his new lawn was horned larks hanging out—and nesting.

Now that the neighbors have all fenced in their backyards, the horned larks have moved on to the still open spaces under construction in the development. But other birds still visit—and more of them are seen on his grass, his jealous neighbors complain, than on their conventional lawns.

Pros and cons of buffalograss

Buffalograss is not a perfect substitute for Kentucky bluegrass.

Buffalograss greens up later than bluegrass and goes dormant in the fall earlier.

Buffalograss does not thrive in shade lasting more than half a day. But bluegrass will.

Buffalograss does not stand up to heavy, constant traffic because it spreads by stolons, connections from plant to plant growing above ground. Bluegrass spreads by rhizomes underground.

In its favor, buffalograss has excellent heat, drought and cold tolerance and few insect and disease problems compared to bluegrass. Though if given too much water and fertilizer, buffalograss will become prone to weeds.

Buffalograss, like some of the other native alternatives, can be a little more work to establish, compared to rolling out a carpet of bluegrass sod.

Buffalograss detail

No need to remove native wildflowers invading your buffalograss lawn–they are perfectly natural. Photo by Barb Gorges.

Pick the right cultivar

Buffalograss comes in several varieties that have been developed for different areas of the country. The newer cultivars grow more densely and greener. Brent is growing one of those new ones, “Cody,” developed in Nebraska. Avoid Texoka, which is more suited to growing conditions in Texas.

Seed is available at local garden centers, but you may have to shop online some place like Stock Seed Farms in Murdock, Nebraska, http://www.stockseed.com, to find exactly what you want, Brent said.

Buffalograss is also offered as plugs and sod. These options aren’t easy to find locally. One place Catherine Wissner, University of Wyoming Extension horticulturist, mentioned is Turf Master Sod in Fort Collins, Colorado, http://turfmastersod.com.

Buffalograss plugs or sod would be worth finding if you have allergies because they are all female plants, propagated vegetatively, so they don’t produce pollen. Look for these cultivars: Legacy and Prestige.

How to plant buffalograss

The 4900-square foot buffalograss lawn cost Brent less than $500 to install by seeding, the cheapest alternative.

The best time of year to start a buffalograss lawn is mid-April to early May, according to one source, or mid-May to mid-June. But it will actually depend on when we are clear of snow. Another possibility is mid-August to mid-September.

Replacing a bluegrass lawn with buffalograss, though, means removing the old lawn. Killing it with an herbicide is not the preferred method. It can be smothered with plastic or just dug up, stacking chunks upside down in your compost area where they will decay. You may opt for replacing a section of lawn each year.

Everything you know about preparing a site for bluegrass works for buffalograss. Get a soil test to see what fertilizer and organic matter might need to be incorporated before seeding.

Remove debris, but don’t go overboard on tilling the soil—it shouldn’t be “fluffy.”

Spraying for weeds before seeding is mentioned in the handbooks, but Brent doesn’t recommend it. Instead, when the weeds emerged, he knocked them down with the mower before they went to seed. The weeds provided a kind of cover crop while the grass got established. And, remember, buffalograss is susceptible to weed killers when it is green.

How much seed do you need? For a small area with seed broadcast using a hand-operated seeder, figure 3-5 pounds per 1,000 square feet. For larger areas where a tractor can pull a drill, figure 20-30 pounds per acre.

If broadcasting rather than drilling, take half of your seed and distribute it while traveling back and forth, and then distribute the other half while traveling back and forth at a right angle. Lightly rake seed in.

To get your seeds to germinate, you’ll need to water lightly and frequently. Once they are established, you can gradually reduce watering.

If you were lucky enough to find plugs or sod, you need to water often enough that they stay moist—not flooded—especially under the sod.

Advice

There is plenty of advice about growing buffalograss—it was first used for lawns in the 1930s.

One publication that can be requested or downloaded is by University of Wyoming Extension staff, “Low-Maintenance Grasses for Revegetating Disturbed Areas and Lawns,”

http://www.wyoextension.org/agpubs/pubs/B1070.pdf. Another is “Landscaping: Turf in Wyoming,” http://www.wyoextension.org/agpubs/pubs/B1129.pdf.

For detailed information about growing buffalograss, consult the Colorado Master Gardeners Garden Notes #565, “Buffalograss Lawns,” at the Colorado State University Extension website,

http://www.ext.colostate.edu/mg/Gardennotes/565.html.