Take Five: Groundcovers

Short plants that spread. That is how I think of groundcovers. They fill in the blanks, knit it all together, they soften edges and suppress weeds. With two acres to fill I have a special love for groundcovers. There is such variety that I indulge in, so much so I've been accused of being a groundcover gardener. I don't know that I agree with that entirely, but these solution plants play a vital role in this garden.

While working at the nursery it was always a fun challenge to find a customer the perfect groundcover based on their list of requirements, i.e., sun, shade, slope, flat, wet, dry, tall, short, flowering, variegated, bees, no bees, scent, dark foliage, aromatic foliage, spread not too fast, spread really really fast, orange flowers, pink flowers, no flowers, soil erosion! Oh my, you get the drift. We could nearly always come up with something, testament to the huge variety available at the nursery (especially with a little creative thinking). I mean, wouldn't you rather see a plant instead of blank soil or even worse - weeds? More plants are better.

Any plant could technically be called a groundcover, but for this particular post I've chosen five that spread easily, are fairly low-growing and are reliable. They just so happen to (mostly) be drought adapted. It was incredibly difficult to winnow this post, I had some 20 different plants with their photos ready to go and kept deleting to keep the length of this reasonable and readable. Ouch, editing is hard. OK, here are the finalists for groundcovers that deliver:

Ceanothus gloriosus 'Point Reyes' is a fine plant to begin with. It is an evergreen prostrate shrub with small-toothed, opposite leaves. It is native to the West Coast of California and Oregon, especially coastal areas.

Once it gets going it readily spreads (much more than I had anticipated), eventually rooting where it touches soil so it is particularly useful for soil-erosion issues. In spring it is covered with very pretty light blue flowers and is well visited by bees. I planted several at about 4' centers and in about three years they covered the Himalayan mounds (as we call them) pretty much completely. So much so that I have plans to move a few plants that have effectively been smothered by the ceanothus to better locales. I do cut it back a little here and there when it encroaches on a path.

Here it is behind Buddha mixing with an unknown purple-leaved ajuga. This is under an Oregon white oak, Quercus garryana, where it actually does quite well. The only issue here is after the leaves of the oak fall for the year it is very messy to clean up out of the spiky foliage of the ceanothus. The leaves eventually decompose and fall onto the soil below, but it takes a while.

Ceanothus gloriosus 'Point Reyes' is an evergreen prostrate shrub that is hardy from about zone 7b to zone 10. It grows beautifully in well-drained, sunny sites or well-drained part shade (as I have it in this last photo under the high shade of an oak). It is useful for soil erosion and can be lightly pruned after flowering. It reaches about 2' tall at the highest points in my garden and about 8' wide. Water well to establish then leave it be. This is on my drought-tolerant list, definitely.

Epilobium (syn. Zauschneria) spp. are excellent groundcovers for sunny well-drained sites. Affectionately known as California fuchsia or hummingbird fuchsia, they do attract hummingbirds when in bloom from mid-summer into autumn. They are deciduous perennials reaching about 10" or so high (some taller, some shorter) and completely die back in winter. The only real maintenance is cutting them back.

Once established they require no summer water, another handy addition to the list of drought-adapted plants. It is a native of the West Coast. Pictured is Epilobium canum, syn. Zauschneria californica.

Here is pretty foliage of a pink flowered form called 'Solidarity Pink'.

This is a rather gray form whose species and name I have lost. I include it to illustrate there are a lot of options out there when adding this spreader to your dry garden.

Epilobium 'Bowman's Hybrid' is more upright at about 24" tall and spreading. 

Flower color of 'Solidarity Pink' in front of one of its rather un-pink seedlings.

Epilobium is a terrific solution plant for hot and dry aspects with average soil, although if it receives summer water it certainly won't complain. It does spread by underground runners but tends to weave its way around plants that are taller than itself. True to its common name hummingbirds do flock to this West Coast sun-loving native. Typically growing to about 10" tall and spreading, they are good for hellstrips and difficult sunny areas that might be out of reach of the garden hose. Most are vibrant orange to red flowers but a few softer colors are on the market such as this soft pink and a white form. Late blooms mean the season is extended. Hardy from about zones 7 - 10. As a side note, they always look crummy in a nursery pot - don't worry, place it in the ground and water it. Chances are it will be gorgeous in no time.

Erigeron karvinskianus 'Profusion' is quite charming, indeed. However it does have the reputation for being one of those plants that seeds in cracks in walls and old masonry, not to mention garden soil. Nevertheless, this post is about groundcovers that are easy and this certainly fits the bill. Commonly known as Santa Barbara daisy, it comes from Mexico.

It is a clumping perennial, sometimes evergreen in my climate if the winter is mild, but I do cut them back in early spring every year regardless if they are ratty or not just to control their size. They spread by seed and seedlings are easy enough to remove. Their petite daisy like flowers are a blend of soft pink to white with a yellow eye. Here it is pictured with Thymus 'Pink Ripple' on the right (before its annual bloom cycle) for a sense of size.

While they don't spread indefinitely, they tend to fill in blank spots and thus act as a groundcover. They bloom over a very long period from spring right through to frost and if I look outside now, I'll likely see a few rogue flowers going in mid-January. They are a romantic, floofy plant that does meet a need, even if they are a little more robust than I would like. Imagining them growing in cracks in masonry evokes a very British garden kind of vibe, one I rather appreciate actually.

It reaches about 10" tall by about 3' wide and grows more profusely with summer water. I don't give it any and it still seeds about a bit, so one to watch if you have a small garden. It is hardy in zones 5 - 8 and is a deciduous perennial but can persist year round in milder climates. Erigeron 'Profusion' could also make a decent container plant. 

Saxifraga is a diverse and fascinating genus of plants. Many species we grew at Joy Creek Nursery were well-suited for rock gardens and trough gardens, some do particularly well as ground covers. The two I list here are in dappled shade, not sun lovers per se but I've seen them listed as such. Pictured is Saxifraga x urbium 'Variegata', a large leaved (for saxifrages) variegated variety that spreads nicely, forming colonies well-suited to the front of the border. In spring its long wiry stems hold pretty star shaped flowers in loose clusters that last for a very long time. It is evergreen and pretty darned tough, spreading nicely and easily propagated by sticking a broken off piece in the soil in the same manner as you would sedum.

This is Saxifraga x geum 'Dentata', another evergreen spreader that has toothed margins on spoon shaped leaves. In spring it too has stems with small star shaped flowers that create a cloud-like effect when in full bloom. It spreads nicely once established to form large colonies in a part shade to shady area with moderately moist soil. This patch is so large now that I dug up clumps and spread it around the shade garden as it performs rather well.

Bonus photo of a few favorites: Saxifraga x geum 'Dentata' to the right of the hosta, Oxalis oregana behind it, below the hosta Austroblechnum penna-marina and intermixed with that is Asarum caudatum, our native wild ginger. All these groundcovers are in the shade garden and pretty much fend for themselves.

Bonus photo of Austroblechnum penna-marina (syn. Blechnum penna-marina), water fern. This lovely little fern is only a few inches high and, oh my, does it spread to form little colonies. Nice groundcover for moisture-retentive soils in shade.

Geranium macrorrhizum may seem boring but, hey, it's one of my top 10 plants ever. Why? It's so easy and is a problem-solver being a great option for underplanting maples and other large trees.

It is evergreen (although new foliage growth in spring rises above older foliage and looks fresh), has spicy-scented aromatic foliage when touched (I love it, other people have said they do not), spreads politely forming impenetrable colonies that suppress weeds and doesn't mind competing for water with big leaved maples or fir trees. That means when I look out my window in mid-January or July to the very tree heavy shade garden, I'll always see some green.

The flowers are in shades of pink, purple and white, mine tend to be in the purple range.

The flowers are insignificant to me (although bees do visit them), it's the fact that they are evergreen, scented and tolerate tough conditions while asking nothing in return that attracts me. I don't even cut them back in spring. They transplant fairly well to get colonies started in other areas of the garden.

Geranium macrorrhizum is an adaptable plant taking sun or shade with little to no water once established. They tolerate a wide variety of conditions, including humidity better than other species of geranium. They stand at about 12" - 15" tall and spread by rhizomes that store water, aiding in their drought tolerance. I do get seedlings in the gravel path which are very easy to remove if desired. They often have brilliant red tones to the foliage if grown in sunny areas and are hardy in zones 4 - 8 (possibly hotter?). There are many fine cultivars of this species, 'Bevan's' is a particularly lovely one. This is just the straight species pictured in my garden.

Knitting it all together: Bonus photo of a few favorites on the edge of the shade garden - Geranium macrorrhizum on the left, Oxalis oregana center and the white flowers are Pachyphragma macrophilla (one of the earliest plants to bloom in mid-late winter).

Oxalis oregana (and Vancoveria chrysantha on the right), both native Pacific Northwest shade groundcovers. Let's talk more about groundcovers that do well under trees. It's one of the most frequent questions asked at the nursery: What can I plant under trees? I usually reply with something along the lines of "Take a cue from nature - from our local forests" - and by golly, Oxalis oregana is one that fits that bill. Our native redwood sorrel is a lovely evergreen (to semi-evergreen) spreading groundcover readily found in our local forests. It does bloom with white to pink flowers; however, it is primarily grown for its foliage. 

It spreads well on slopes, too - covering the ground with fresh green foliage. Here it is pictured with our native sword fern Polystichum munitum and Juncus effusus, a native grass. This is on what was rather bare soil a few years ago, now covered with this somewhat aggressive groundcover. If you don't have space for such a plant, I get it, but it's such a useful addition to the shade garden. If you don't water it in summer the spread slows - so perfect for those hard to reach areas under large trees that receive little water in summer.

It is lovely and serves an important purpose in my large garden. The darker leaved form on the right is Oxalis oregana 'Klamath Ruby' with darker foliage and a much pinker underside to the leaf. This is not as aggressive as the straight species in my experience. The flower color is also pinker in my garden.

It's a charmer! Great for creating a soft green carpet in dry shade. It looks lovely with a little summer water but definitely does not require regular moisture. The leaves fold up when in sunshine.

Oxalis oregana is about 4" high x spreading (via rhizomes), evergreen to semi-evergreen (dies back some in severe drought or freezing events in my experience), makes a great carpet in a woodland or shade garden, is visited by pollinators when in bloom, is a West Coast native and one of those great solution groundcovers. It is aggressive when it's happy, but we are looking at easy groundcovers in this post, so I include it here as one of the best for shade.

As it turns out, this selection of groundcovers is entirely drought adapted (save for the Austroblechnum penna-marina and maybe the saxifrages, although I don't particularly water either in summer) and all are easy, forgiving, spreading, solution plants. Of course, last week's post included creeping thyme and Eriophyllum lanatum, (both of which I categorize as groundcovers) which are both extremely drought adapted, so don't forget those. Another worth mentioning is Dorycnium hirsutum, hairy canary clover that forms a low, wide sub-shrub but looks like a groundcover at about 2' high x spreading. Check that out if you have a lot of sun and well-drained soil.

OK, what's next, good garden people of the world? What shall we cover in the next Take Five post? Ideas are welcome!

That's a wrap for this week at Chickadee Gardens. As always thank you so much for reading and commenting, we love hearing from you! Happy gardening!