Six Native Groundcovers That Thrive in the Sun

As you think about your native landscape, taller plants are easier to plug into the design.  There are more choices from which you can add diversity, color, texture and habitat.  These taller layers are the backbone of any plan, while the edges or ground level are often overlooked.   In my opinion, the border plants are just as important because they define the edges.   The larger perennials typically overshadow these native groundcovers, but here are a few that stand out in the landscape.

Missouri Evening Primrose-Oenothera macrocarpa

In the wild, this low growing wildflower is found clinging to exposed hillsides.  If it can survive that environment, it will be a tough drought-tolerant plant for any sunny spot.  The large, showy, yellow flowers bloom from May through August, but the majority of the blooms come in April and May.  One plant can spread up to 24 inches while only reaching 6 to 12 inches tall.  Obviously, it likes it dry, so don’t over water them.  They look great along walkways or spilling over rock walls with their silver green leaves and reddish stems.

Purple Poppy Mallow-Callirhoe involucrata

Some like it hot, but these like it really hot.  The deep tap root of Purple Poppy Mallow sustains it during times of drought.  These roots are starchy and supposedly taste like a sweet potato.  (I don’t know if I am that hungry, but it may be worth a try.)  The magenta cup-like blooms appear throughout spring and into summer.  I like to interplant with low grasses or shorter perennials that bloom later in the season, such as blazing stars or goldenrods.  The stems hug the ground and ultimately spread 24-36 inches wide and 6-12 inches tall.

Blue Grama ‘Blonde Ambition’-Bouteloua gracilis

Unlike any other native grass, ‘Blonde Ambition’ will make an impact in your garden.  The eyelash-like seedheads dance with even the gentlest breeze atop the fine blue-green foliage from mid-summer into winter.  Selected for its unique habit and hardiness, it can be used in a variety of settings from clay to sandy soils.  It gets larger than most Blue Grama grass, maxing out at 24 inches.  Space them 18 to 24 inches apart for best display.  Regularly, Blue Grama is found growing with Buffalograss in the shortgrass prairie, making it an important native grass of the Great Plains.

Rose Verbena-Glandularia canadensis

This plant holds the record for most months in bloom.  I have seen it in bloom from March through December.  It is one of the first to bloom in the spring and if we get some beneficial rain in the fall, it will bloom again.  In the prairie, rose verbena can be found in open bluffs and rocky outcroppings.  It requires minimal rain and terrible soil for the best growth.  Sounds like a winner to me.  The vibrant pinkish-purple blooms will brighten any border.  Give it room to spread.  One drawback is that they are not very long lived, every few years, plants will completely die out or move.  I think that they bloom themselves to death.  Just replace with new plants and again enjoy this sun loving groundcover.

Rose Verbena-Photo courtesy of Craig Freeman

 

Stiff Coreopsis-Coreopsis palmata

Each spring, the golden yellow blooms of this prairie beauty burst open with an eruption of glorious sunshine.  The stems are lined with leaves that resemble little hands lifted skyward.  It is a favorite of pollinators as they flock to the nectar rich flowers from late spring to early summer.  I give it some room to roam since it slowly spreads to fill in an area when it is happy.  Eventually, spreading to 36 inches or more and growing 24 inches tall, this wildflower is a great alternative to its other coreopsis cousins.

Coreopsis palmata-By Frank Mayfield (Flickr: Coreopsis palmata PRAIRIE COREOPSIS) [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

Prairie Dropseed-Sporobolus heterolepis

At one time, this was one of the top selling grasses nationwide.  It is a favorite of mine because it is long-lived and tough.  It is so tough they are planted in mass in street medians.  The fine textured leaves and airy, fragrant panicles are a nice addition to any landscape.  Each clump can reach 12-18 inches wide and up to 24 inches tall.  The entire plant turns shades of orange and yellow in the fall providing multiple seasons of interest.  It is great in a border, as a groundcover, in an informal prairie setting or as an accent to other short or mid-range perennials.

 

Sporobolus heterolepis-By Krzysztof Ziarnek, Kenraiz (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

A Weed By Any Other Name

Here at the Dyck Arboretum it can be a tricky task deciding what is a weed to be pulled and what should be allowed to grow on. Many of our beloved volunteers look to me for guidance when they encounter a plant that looks out of place. What is a weed here?

Many wonderful prairie plants carry the misnomer of “weed”, such as butterfly weed, iron weed, and milkweed. These are plants that may or may not need to be pulled, depending on where they are located. I consider a few factors: does the plant belong here or fit the theme of that garden bed? Is it annual or perennial?  Will it become invasive? Is it part of a plant family that is notorious for colonizing? …and so on. Weeding will become less of a guessing game when you learn to identify some native species and  particularly those nasty exotics.

While the name ‘milkweed’ might cause you to shun this plant for your garden, think before you pull! In the right area, milkweeds may be a perfect addition. They will bloom for several weeks and add a bit of important monarch habitat to your backyard. Photos from Dyck Arboretum.

 

“Where do they come from and how can I beat them?”

Just when you think you have weeded every last square inch of your garden, here they come again.  The seed bank – dormant seed that exists in the top soil – will continue to produce more weeds as long as conditions are favorable. Seeds can lay dormant in the soil for long periods of time, waiting for adequate moisture and light levels. Bindweed seed can remain viable in the soil for up to 50 years! The seed bank is created by last year’s mature weed seeds, bird droppings, hay/manure used for mulching, and seeds carried on the wind. The good news? With regular weeding and mindful practices you will decrease your weed seed bank every year. That means pulling weeds before they seed, using carefully sourced mulch material, and disturbing the soil as infrequently as possible to reduce the amount of dormant seeds awakened by light and oxygen.

Some weeds are obvious

Bindweed with it’s morning glory bloom, Siberian Elm saplings with their small serrated leaves, and prostrate spurge with its circular, flat habit all send up the red flag. These kinds of plants look out of place right away because they lack charisma and often grow in inhospitable areas. (i.e. in driveway cracks and gravel, climbing up stems of other plants).

Some weeds are ambiguous

Virginia creeper vine seems to crop up everywhere, and are very decorative if left to grow in a good spot. But they can also be aggressive when not trimmed regularly. Similarly, a mulberry sprout (which tend to come up just about everywhere a bird flies over), could be left to grow into a nice fruiting tree if you are prepared for the berry-mess and seed spread. Plants like ironweed and Illinois bundleflower seem to pop up everywhere and, though they can be aggressive spreaders, they are also quite attractive.

Ironweed (Vernonia sp.) may at first appear as an intruder, but it produces a colorful, longlasting bloom and is a favorite of swallowtails and many species of bees.

Ironweed (Vernonia sp.) may at first appear as an intruder, but it produces a long lasting bloom and is visited by many species of bees. Photo from Dyck Arboretum.

Some weeds are not weeds at all

I always advocate for leaving milkweed in the garden as habitat for monarchs. Lucky you if a few come up!  Other species like purple poppy mallow and wild petunia that may appear weedy at first actually make well behaved native specimens. These species bloom all summer long and are extremely drought tolerant.

 

While you pull and pluck away at the weeds in the garden, remember the wise words of the poet Ella Wheeler Wilcox – “A weed is but an unloved flower”. Although weeding is the tedious task all of us gardeners must endure, you can make it easier and more productive by knowing the difference between potential friend and foe.