Nigella is a half-hardy annual that self-sows readily and emerges early.
Erica Browne Grivas
There’s no need to have a bare garden in winter — especially in Seattle. As gardeners, we are fortunate (at least on this side of the Cascades) to enjoy relatively mild winters. For me, that’s relative to other states I’ve lived in, namely, New York, Connecticut and Illinois.
To create a garden that looks great more of the time, design it using sound principles: include plenty of evergreens for stability and seasonal changes for excitement. You don’t get a pass on that. However, our weather gives Seattle gardeners an extra tool — a design cheat code, if you will: half-hardy plants that can take a few degrees of wind chill, enabling them to stay late and return early. These plants can give your garden a shot of adrenaline in the shoulder seasons when most are going to sleep in fall or waking up in spring. They are the first to come to the party and the last to leave.
I’ve discovered many of these by accident, nearly stepping on nigella seedlings emerging in my parking strip in January, or sheer laziness, from not trimming back a hanging basket to find the trailing verbena is all leafed out again in December. They fall into three categories: half-hardy annuals and semi-evergreen (for us) annuals and perennials.
Half-hardy annuals
Half-hardy annuals are plants that fulfill their life cycle from seed to flower in one year, just like standard annuals, such as cucumbers or sunflowers. Where they differ is that they will often set seed in fall that can happily snooze in the ground over the winter, sprouting earlier than you will find them at the nursery. So even if the plant you planted is gone, there is still a crop of newcomers in the general area. In fact, in my yard, although not considered half-hardy annuals, both sunflowers and tomatoes have sown themselves for the next year, emerging around April.
For some half-hardy annuals, an especially balmy winter lets the individual plant live on for another season or two, like the snapdragon (Antirrhinum majus) in the pot by my door right now that shocked me by being alive in December. There’s another in a large clay pot about to bloom as I write this in February.
Some examples of half-hardy annuals to play with include calendula (pot marigold), nigella (love-in-a-mist), cerinthe major (honeywort) and annual poppies from papaver somniferum (breadseed) to P. nudicaule (Iceland) and P. rhoeas (Shirley), not to mention California poppies, which are botanically eschscholzia californica. Given proper conditions and encouragement (watering), they can persist for years.
Other half-hardy or hardy annuals worth trying include alyssum, amaranth (which includes edible quinoa), ammi, borage (edible blue flowers), bupleurum, cardoons and artichokes, callistephus (China aster), centaurea (bachelor’s buttons), and consolida ajacis (Larkspur). It’s worth double-checking each plant’s cold-hardiness and sowing directions.
Calendula is especially long-blooming, especially with dead-heading. Nigella and annual poppies benefit from repeat sowing every three weeks or so to keep the show going. Many can be direct sown in fall, or even earliest spring while there is still a chance of frost.
‘Regular’ annuals with staying power
While there is much that looks toasted or melted in my garden in February (I’ve left a lot of stalks up for insect cover and bird nutrition), there are some delightful surprises which likely would not be visible in New York or Chicago at this time.
Several annual primroses have made it through winter unscathed, and one in a 1-gallon plastic pot is even blooming. I’ve noticed that often here, the driest, most well-drained situations are the best for these borderline plants, including dahlias, echinacea and more. My south-facing sandy hillside can be counted on for a few primroses, but the wetter area by the fence has led to more than one demise, even though it faces west.
Perennial strawberries are showing their charming trefoil leaves both in the pots and planters and running amok on that same hillside.
The biggest surprise, by far, is the geum. Besotted by their ruffled flowers in sunset colors, I’ve planted many, but it wasn’t until I tried them in pots (drainage) that they lasted a year — this year two varieties in two different pots and locations. And they’ve not only stayed completely evergreen but have put out occasional blossoms regularly since fall.
For undaunted staying power in the winter, look to stalwarts like carex, heuchera (most) and especially hellebore, which come into their own with weatherproof blossoms that fade on their stalks for a two-month show at minimum. The beds at University Village are lined with these for good reason — it gives a standing backdrop for a seasonal show of shrubs and perennials that come into bloom and fade away.
Need more ideas? Take a walk and take note of what’s looking good in the neighborhood from groundcovers to trees, and you’ll create a garden that inspires you year-round.