Groundcovers

Posted by on November 10, 2008 in Uncategorized | Comments Off on Groundcovers

The hot topic of conversation among gardeners this year
seems to be the future of the American lawn. Does it make sense to water and
feed that stretch of grass in front of the house during summer droughts? Are
chemical fertilizers, pesticides, and nematocides safe for children and
pets? Does anyone really have time to
mow and edge and weed? And what about providing a habitat for birds and
butterflies? The typical lawn may be home to a few earthworms and a couple
species of ants, but that’s about all. For more and more gardeners, groundcovers are an attractive alternative.


But
groundcovers aren’t just a substitute for lawns. You can have your grass and
groundcovers, too. They work well in
shady areas or under trees where grass won’t grow; they can help stabilize
slopes and erosion-prone areas; they can fill in gaps around patios, decks, and
walkways, where grass would be difficult to mow; and they can provide a
transition between the more manicured sections of a garden and wilder areas.

The first
step is to decide what works for your space. Do you want a small, low-growing creeper that will tolerate a little
foot traffic? Or are you looking for something more like a low-growing shrub
than a grass substitute? Are you
willing to spend a little time every few months deadheading, trimming, and
cleaning up a plant that would otherwise spill into pathways or get shaggy and
overgrown? What about water and sunlight? And will the plant have to be vigorous enough to out-compete the weeds,
or are you planting on a blank slate?

We’ll get
to some suggestions in a minute. But first, it’s important to invest a little
time in ground preparation. If you’re
removing an established lawn, it may be a fairly simple procedure to rent a sod
stripper or to simply peel back sections of lawn with a shovel. Lawns can also be smothered with one to
two-inch layers of damp cardboard or newspaper topped with compost, grass
clippings, dried leaves, and mulch. Built up a thick enough layer of organic
matter, and you can usually give it a few weeks to settle and then plant
groundcovers right into it. The
newspaper or cardboard will break down gradually and smother the grass and
weeds while the new plants get established.

What if you
are battling an existing groundcover, like invasive Himalayan blackberries or
English ivy? Take comfort in the knowledge that you’re not alone. Many homeowners have had to dig out
pernicious weeds before they got a new groundcover established, but the effort
is well worth it.  Some gardeners hire a
crew to cut back vegetation, dig out roots, and level the ground. One couple I know rented a large chipper
shredder about once a month to shred the bramble they were removing and turn it
into mulch. One word of caution: if the
plants you’re pulling out are diseased or tend to produce a lot of seed, you
won’t want to add them back to your garden as mulch. But in many cases, the shredded remnants of your old landscape
can decompose for a few months and become an excellent soil amendment.

Once the
existing plants or weeds are removed, water the ground well and wait a few
weeks to make sure nothing else sprouts. Ideally, you may wish to repeat this process for a few months, as plant
roots regenerate and try to take hold again. And although most native groundcovers do well in poor soil, it never
hurts to work in a few inches of compost before you plant.

Some people are tempted to add a
permanent layer of plastic landscape cover at this point. I recommend against it; if your goal is to
create a natural environment, it’s important that the soil not be buried under
a layer of plastic. Birds foraging for
bugs and worms will want to be able to dig around in the dirt, and as your
groundcover sheds leaves and berries, that organic matter should come in
contact with the soil so that it can break down and help support plant
life. Finally, many groundcovers
reproduce by sending out runners, so covering the soil with plastic will keep
the plants from getting established.

And now for
the fun part– choosing what to plant! Walk around your neighborhood and look
for groundcovers that are doing well. If you’re not sure what a particular plant is, snap a few pictures and
take them to the nursery for identification. Notice what groundcovers are growing well in parks and wildlife areas
near your home. Finally, check with
your local native plant society and get some recommendations. Be sure to ask them what groundcovers not to
plant. Some of the most popular
groundcovers for sale at garden centers are also the most invasive. While you want a groundcover that gets
established quickly and fills in thoroughly, invasive plants will not only take
over the rest of your garden (and your neighbor’s!), they may move into fragile
ecosystems as well.

In California,
where the arrival of autumn also means the end of the summer drought, this is
the best time of year to plant new groundcovers. They will spend the winter
putting down roots in getting established, which will help get them through
next year’s dry summer. However,
remember that even native plants will need supplemental water during their
first year.

Some of my
favorite groundcovers and lawn alternatives include:

Beach
strawberry (Fragaria chiloensis) This California native puts out runners
and quickly scrambles over slopes and across sandy areas. The leaves may turn red in winter, but are
usually not bothered by frost. You’ll see small, white flowers in spring, and a
few berries in the fall, which are attractive to birds but not typically as
large and juicy as commercial strawberries. Beach strawberry thrives with no care at all once established, but if it
starts to get woody, you can mow it once in spring or simply run a rake through
it to remove dead vegetation.

Thyme (Thymus
spp.
) Thyme makes a wonderfully fragrant groundcover and can tolerate a
little foot traffic. Just remember that many varieties bloom and attract bees,
so run across it barefoot at your own risk. Most varieties of thyme grow slowly and can become woody after a few
years, so it works best as a groundcover in small spaces and in between
stepping stones, as opposed to a large-scale lawn substitute. Thyme prefers full sun, but will take a
little shade in hot summers. Experiment with different varieties to find the
one you like the best; the most popular groundcover options are wooly thyme, or
T. pseudolanuinosus, or creeping thyme, T. drucei. If you want some for your kitchen, mix in a
few culinary varieties of common thyme, T. vulgaris.

Junipers (Juniperus
spp
.) There are dozens of low growing junipers available as
groundcovers. Colors range from bright
chartreuse to silvery gray to dark green or almost blue. In fact, you can
choose a few different colors to create a mosaic effect. If you do mix
varieties, make sure that they have a similar growth habit so one does not
overwhelm the rest. Some junipers produce berries that are attractive to birds,
and they all provide excellent cover for foraging. Many are slow-growing, so
plan on giving them a year or two to get established.

Ceanothus (Ceanothus
spp
.) Ceanothus are primarily native to California and the western half of
North America. They produce beautiful blue or lilac clusters of flowers are
very attractive to bees and butterflies. Some varieties grow into shrubs or small trees, but you can find a
surprising amount of variety among the low-growing groundcovers. Some of the groundcover varieties grow to
two or 3 feet tall, but there are several that hug the ground and reach only 6
inches in height. It’s an excellent plant
for slopes or erosion-prone areas.

Cotoneaster (Cotoneaster spp.)
Cotoneasters are popular groundcovers shrubs because of their striking foliage
and brilliant red berries. However,
these plants are native to Asia, and a few varieties do have invasive tendencies,
so be sure to check with your local native plant society before choosing a
variety. Having said that, these low
growing, spreading shrubs provide erosion control, choke out weeds, produce
lovely small pink or white flowers in spring, and light up the winter garden
with their red berries.

Manzanita (Arctostaphylos spp.)
What’s not to like about manzanita? This is another California native that thrives in poor soil and demands
just one watering a month during hot summers. Manzanitas do require a little pruning to encourage new growth, but the
effort is worth it. Many manzanitas are shrubs and small trees, but the low
growing groundcovers like ‘Emerald Carpet’ form dense mounds and produce pink
flowers in spring.

California fuchsia (Zauschneria
californica
) This silvery, drought
tolerant native produces red, trumpet shaped flowers that attract hummingbirds
like mad. Some varieties grow as much
as two or three feet tall, but many remain compact and will scramble over
slopes and spread up to four feet wide. This is a delightful plant that requires very little care. To keep them from getting too woody, cut
back leggy growth in the fall and let them renew over the winter. If you’re worried that this will leave a few
holes in your garden, scatter some California poppy seeds to fill in the gaps.