Perennials for winter? No, I'm not suggesting that you travel
to a warmer climate to see these at gardens (not a bad idea, though).
Nor am I suggesting you try growing them indoors overwinter although
some you can, especially if you have a cool space like an unheated
bedroom or hallway with light.
What I am suggesting is that you consider choosing some perennials
now, to buy and plant this next season, to give nice effects in
the winter garden.
Of course, you won't have blooms on perennials in winter this
far north, but the spent blooms and flower spikes can be quite attractive,
especially rising up through the snow. The foliage of many ornamental
grasses can be beautiful as well, especially covered with frost
Perennials with tall spikes, especially those that bloom in mid
to late summer, often hold up well into winter. For shorter (one
to two foot) perennials, consider the speedwells (Veronica).
These are quite popular now, and generally hardy in the north.
Depending on the variety, these range from six inches to three
feet tall. One I particularly like, and have had good luck with,
is called 'Sunny Border Blue' (named after the wholesale nursery
in Connecticut that developed it). It has six-inch flowers on spikes
about two feet high that last several weeks. Even as a cut flower
they can last up to two weeks in a vase.
Ligularia 'The Rocket' has tall yellow spikes midsummer, about
three to four or more feet high. They keep their shape well after
bloom, adding structure in fall and winter to the back of a border.
These like moist feet, even wet at times, so place appropriately
in your landscape.
The plume flower, or Astilbe, has many cultivars, most reaching
around two feet high. In midsummer the thick plumes of astilbe are
generally red, pink, purple, or white. They have a nice tan or brown
color into fall and winter. Astilbe cultivars range from six inches
to three feet tall (usually the purple flower varieties). The taller
cultivars of astilbe like 'Superba' and 'Purple Candles' generally
bloom later in summer, and again, last nicely into winter.
Then there are the other flower forms to consider for a winter
garden. The golden black-eyed daisies, such as the Rudbeckia 'Goldsturm'
have nice small cones on one to two foot stems in winter. Similar,
but a little taller, are the coneflowers (Echinacea). These
may be pink/purple or white and bloom later in the summer.
They can self-seed in the garden, so keep this in mind when deciding
where to plant. Self-seeding is nice if you want a whole bed of
them, or don't mind hoeing the seedlings out each year.
Helenium, or Helen's flower, is another good choice. Helenium
grows to heights of four or five feet with orange to red or yellow
flowers in early fall.
Other perennials you might consider are the Joe-Pye Weed (Eupatorium
'Gateway'), which has five to six-foot purplish flowers in late
summer with lasting bloom. Black snakeroot (Cimicifuga) has
spikes six to eight feet tall. It produces white flowers in late
summer, which will last into winter.
Some of the purplish leaf forms like 'Hillside Black Beauty'
also are quite popular now. Or try perennial sunflowers (Helianthus),
such as the common 'Summer Sun' or the new double 'Bressingham Doubloon.'
These have golden yellow flowers in late summer. They grow three
to four feet tall, forming large spreading clumps. They are sometimes
self-seeding and will provide winter structure in the mid to back
My favorites for the winter garden, however, are the ornamental
grasses. Some, such as the Foxtail grasses (Pennisetum),
are generally not hardy in our colder climate. Others, like the
many Maiden Grasses (Miscanthus), may be marginally hardy
in our area, depending on the year and cultivar.
One that seems quite tough ,though, is the purple-leaf variety
(Miscanthus purpurescens). It forms a clump, which gets bigger
but doesn't spread, and grows to four to five feet high. The silver
plumes of Miscanthus purpurescens open in late summer and last all
winter, with the purplish green foliage turning russet orange in
fall then a nice brown through winter.
One Miscanthus to avoid, as it is totally invasive by its roots,
is Miscanthus sacchariflorus. Once you have it, you may have
it for life! You may read elsewhere that this genus of grasses is
seed invasive. However, in the north, with our cooler climate and
shorter season, these never seem to get the chance to go to seed,
so seldom are a problem in this respect.
Other hardy favorites include the Moor Grasses (Molinia)
with their tall, narrow spikes waving in the breeze. The Switch
grasses (Panicum) are upright clumps, with one cultivar having
reddish leaves ('Rotstrahlbush') and other new ones with bluish
leaves (such as 'Cloud Nine' and 'Prairie Sky').
The Tufted Hair Grass (Deschampsias) form a mound of foliage
about two feet high and across, with even taller arching spikes
coming out late summer and turning a nice light brown through winter.
These remind me of a fountain or exploding fireworks.
These are just a few examples of the many perennials to add to
your garden for a four- season effect. Check with the experts at
your local nursery or garden center for other suggestions.
Dr. Leonard Perry, Extension Professor