Groundcovers for Sun

I presented a program to the Master Gardeners of Columbia County in September. The request was for a talk about ground covers, a large topic to cover in an hour, but somehow I managed to cram in tons of possibilities. Now, on a rainy January day while daydreaming of being outside, I revisited the presentation and remembered a couple readers requested a blog post about groundcovers. Here then is Part I: Groundcovers for Sun. A separate post about groundcovers for shade is in the works.

Groundcovers are a broad topic. What makes a plant a groundcover? I think of them as broad, spreading plants. Some are aggressive and others have a clumping habit. Most are pretty low growing, although you could, for argument's sake, consider our native sword fern, Polystichum munitum, a groundcover. For example, if you've ever walked through our local forests what often covers the ground? Ferns, that's correct. They colonize under native fir trees. It's a bit subjective, so what I've tried to put together here are a group of plants that I think of as the shortest, most spreading plants that I have experience growing in my own garden and in the gardens at Joy Creek Nursery.

Benefits of groundcovers: They serve as a living mulch, preserving water in the soil by shading it. They add texture and tie a garden together visually. Many have benefits for wildlife including flowers, cover and fruits. Many are dense enough to act as weed suppressors. They also allow for another layer in your garden, the base layer, so why not have fun and get creative with what is often overlooked. 

Let us begin from the ground up with the rather low-growing groundcovers. Creeping thyme can be pretty low, although cultivars such as 'Foxley' reaches a foot or so in height in my garden. This is Thymus 'Pink Ripple' at its tallest, while in bloom. This patch took about four years total to fill in from a couple flats of 4" pots. Great drainage for these guys. I had customers at Joy Creek wonder why their creeping thyme had died until we unraveled the fact they watered them nearly every day. Don't do that.

Acaena 'Blue Haze' is a very low grower and does spread by creeping and by seed. These burs attach to everything, so not pet-friendly as they especially love fur. Nonetheless, great color and tucks in easily in well-drained sites. It is listed as best for part shade, but this patch at Joy Creek gardens is in full baking sun and I have it in the same situation at home. It seems to be adapted to many conditions.

My favorite acaena is A. inermis 'Purpurea'. It definitely likes wetter soil and will fry in full sun with dry soil. It also is more winter deciduous. Such a pretty contrasting color and not as aggressive, for me, as 'Blue Haze'.

Delosperma or ice plants are excellent spreading succulents. This is Delosperma 'Oberg'. Many more in the trade, some with vibrant orange or red flowers. I have lost some in terribly frozen winters but many are hardy for my zone 8-ish garden.

More creeping thyme around the fire pit. This has since filled in. Thymus serpyllum 'Elfin' is incredibly flat, perfect for this kind of application. It takes some foot traffic and has brilliant purple-pink flowers in summer. Little to no summer water makes it even more attractive.

There are so many sedums that I use as groundcovers, I should do a post dedicated to this genus. Pictured is Sedum album with Galium odoratum, sweet woodruff, blooming white behind it. Beyond that is Ceanothus gloriosus. This is a tough spot under an oak tree, but as you can see there is a nice carpet of green. It all stays in check as it is a difficult growing situation. Sedum album can spread rapidly - a good thing or a bad thing depending on whom you ask.

Our native Sedum spathulifolium 'Cape Blanco' at Joy Creek Nursery. A sweet spreader, not aggressive but charming and it's evergreen. Well-drained soil, yes, and also it does well in some shade. 

Sedum kamtschaticum 'Variegatum' likes well-drained hot sites. Completely winter deciduous and not super-aggressive. Below it is some form of Sedum spurium, a great fast spreader if that's what you need to cover a lot of ground.

Sedum oreganum, another native sedum with a bit of Delosperma 'Fire Spinner' that crept in. I find this evergreen sedum is excellent in a variety of locations - hot sun to part shade in any number of soil types. Very good front of the border plant that really brings on the pollinators when it blooms yellow flowers in summer.

Antennaria rosea, another native, has a petite clump of glaucus basal foliage and pretty spikes of pink flowers. Dry, well-drained sites are perfectly suited to this. It spreads to form a good wide mat of foliage in time, this plant is fairly young.

Moving up in the world to a few evergreen woody prostrate shrubs that act like groundcovers. This is Arctostaphylos 'Pacific Mist' and is on its way to taking over its territory. It gently cascades down this rocky wall (now completely obscured). With its soft coloration and elongated leaves, it's an arcto definitely worth growing if you have a site in full sun to partial shade with good drainage.

Ceanothus 'Heart's Desire' in a newer garden bed at Joy Creek Nursery. Small, evergreen leaves with prickly margins, it is a tough one once it's established in a garden setting.

Ceanothus gloriosus 'Pt. Reyes' is another ground cover ceanothus. It's great for erosion as it eventually roots where it touches the ground. It gets a foot or more tall in my garden and spreads fairly rapidly once established after a couple of years. I now have to keep pruning it back from encroaching on paths and it doesn't seem to mind.

Arctostaphylos uva-ursi, our native kinnikinnick is an evergreen spreading (slowly!) arcto that is fine in sun or some shade so quite versatile. Its rounded leaves are user friendly and its typical bell shaped arcto flowers are loved by bees. As you can see here it is on the edge of a retaining wall, so not the best drainage, and it loves it. It's low at only 7" or so tall but spreading nicely once it's established. I only wish it grew a little faster, this plant is easily 6 - 7 years old.

There are prostrate hebes out there and this is my favorite. Hebe 'Wingleteye' has rather small, blue foliage and in summer a mass of purple blue flowers. It has been amazingly tough and doesn't require any attention from me yet always looks top notch.

Rubus c. 'Emerald Carpet' is an evergreen spreader. In winter its leaves often change to shades of orange and red adding a little interest. It has rough leaves and is commonly known as creeping raspberry. Its flowers are insignificant but it's grown for foliage. Sun to part shade and good for erosion control.

A petite native evergreen penstemon, P. davidsonii is only an inch or so high and has disproportionately huge flowers in purple blue. Definitely lean, well-drained soil and full sun. I rescued this plant from the compost pile years ago and stuck it in basically gravel in a sunny site and it has grown to a handsome 3' x 3' mat of pretty foliage.

Veronica hookeriana var. olsenii (syn. Parahebe olsenii), an evergreen shrublet from New Zealand, is a sweet addition to the garden. It likes sun to dappled shade and a little extra irrigation in summer.

Our native parsnip flower buckwheat, Eriogonum heracleoides is technically evergreen but it is much denser and greener in the warm months. Very lean soil in full sun. Not a huge spreader per se, but it is fairly low and slightly spreading so I love it at the front of a bed as a small scale groundcover.

Dorycnium hirsutum, hairy canary clover, is a semi-woody sub shrub but it gets so wide it's a groundcover on the taller side of things. It has pretty soft silvery leaves and these clover like flowers in summer that attract bumble bees, especially. Full sun and well-drained soil and it seeds around in my gravel path. Having a very long tap root it survives with no summer water.

Moving on to perennial ground covers that are a little taller. Persicaria affinis is a more well-behaved persicaria species for me. It politely spreads and has not really extended past its 3' x 3' area in several years. In late summer through fall it blooms pink spikes that turn brick red as they age adding an interesting color harmony. It's pretty much deciduous (and not pretty in winter) but it grows out of it quickly in early spring. It appreciates a touch of summer water.

 Sibbaldiopsis tridentata is a spreading groundcover with charming attributes. Its leaves turn reddish in the cold and it has pretty white flowers atop wiry stems in spring. It's not evergreen for me but almost - you can detect bits of the plant but it's definitely in a dormant stage in winter. It makes a wonderful rock garden plant and is quite easy with well-drained soil.

On the floofy side of things, Erigeron karvinskianus 'Profusion' adds romance. It seeds about, yes, but it's not too difficult to remove in my garden. It's a great filler and also looks lovely in a container as a filler. I give these a good hard haircut in late winter, even if they haven't died back much the previous winter just to keep them compact for a while.

Stachys 'Helen von Stein' is a spreading, fuzzy, glaucus-leaved beauty that loves it hot and dry. It's a mushy mess in winter but, like so many other plants, grows out of it quickly in early spring. Its flowers are few which is lovely as I love it for a foliage plant, but the flowers spikes that do appear tend to attract pollinators. Grows to a height of about 12" or so with a spreading habit, but tends to run out of steam if it encounters another plant in its way.

Dianthus hispanicus in full, candy-coated bloom. These smell like cotton candy, really. With evergreen fine basal foliage, this front of the border perennial/small groundcover holds its own in no-water gardens. A good haircut post-bloom will tidy it up and maybe even provoke a second smaller round of flowers. I have several of these lining a path in the labyrinth garden. If they get too large (wide) I cut off several inches of its width in early spring.

Dianthus 'Little Gem' is another in this fabulous genus of plants, this one doesn't have the fragrance of most but it has a punch of color. Evergreen basal foliage for well-drained sunny sites.

Our native Oregon sunshine, Eriophyllum lanatum is a burst of brightness. It has glaucous evergreen basal foliage and blooms over a long period of time. It's about 2' or so tall when in bloom. I give it a haircut after flowering and truth be told, it doesn't look great for a good couple of weeks before it fills in again. Still, it attracts those tiny flying pollinators that you can barely see without glasses, so it's worth it. Full sun, well-drained soil, nothing too rich. No summer water, either.

More natives, Epilobium canum, syn. Zauschneria californica, hummingbird/California fuchsia. It's a definite spreader and completely deciduous. It blooms late in the season right up until first frost and as its name implies, the hummingbirds do adore it. Dry, well-drained soil and full sun for just about all of the California fuchsias.

For cheerful colors in full sun, you can't beat helianthemum. This is Helianthemum nummularium 'Fire Dragon', a small evergreen shrublet or groundcover with silverish evergreen foliage.

This is Helianthemum 'Henfield Brilliant', a rather orange-red flower that is great for dry gardens, although last year's super wet spring did these guys a lot of good. They'd never looked so lush.

A few ornamental grasses act as groundcovers in my garden. This is Festuca rubra 'Patrick's Point'. A West Coast native evergreen blue-ish grass, it spreads very slowly. I have it paired with Muhlenbergia rigens which gives a green/blue effect and also short/tall.

Behind the chairs is a clump of Carex flacca which is also good with a little shade. It spreads into frothy clumps. I give it a good comb out early in the season to clean them up, but that's about it. They are spreaders, although not obnoxious in my experience.

More grasses, this is Carex comans in spring mixed with our native annual Limnanthes douglasii, Douglas' meadowfoam. When the meadowfoam goes to seed and dies, the grasses cover what's left, obscuring any brown bits.

Carex comans a little later in spring looking greener and fuller. It does seed around a lot, however its roots are very shallow and easy to remove with one good yank. I think it seeds a lot in my garden because gravel is an excellent medium for germinating seeds.

Another shot of Festuca rubra 'Patrick's Point' earlier in the season before the flower spikes emerge. It's such a pretty and soft color. It also gets the comb treatment in late winter to help remove dead bits and allow for new growth to shine.

Tying it all together: Pictured is Sedum spurium, Epilobium canum, Armeria maritima, Acaena inermis 'Purpurea' and Arctostaphylos 'Pacific Mist'. All are used as groundcovers and all do best with full sun, although a bit of high overhead shade passes through here in late afternoon.

Pictured is Acaena 'Blue Haze', Arctostaphylos uva-ursi, Sedum 'Angelina', Sedum spurium and Sedum oreganum. They all just battle it out, creating a tapestry atop a short retaining wall. I like to think of it as my waist-level eco-roof planting.

My garden is actually very ground-cover heavy, I love having plant material cover the ground so I use them extensively. Sedum spurium is a very fast spreader that is a go-to for filling in blank areas, but use anything with a fast growth habit with a bit of caution - I also rip out a ton of it every year. Sedum 'Angelina' and other ruprestre forms are equally as aggressive. For some situations that's what you want, but if you have a small garden it might take over. Epiliobiums do that, too. I had E. canum in the old garden that I had to move after just a year in the ground, it was just too much for a small space. I saved it in a pot and took it with me here where it's allowed to spread to its heart's content. 

That was a lot to go over and there are so many others not covered here. This is merely a sampling to get us all excited for spring planting and to think of those bare areas under plants that could be planted up with some pretty groundcover or another. So, tell me, what is your favorite groundcover for sun and why? Let's get this going! That's a wrap for this week at Chickadee Gardens. As always thank you so much for reading and commenting, I love hearing from you. Stay tuned for: Groundcovers for Shade next time.