Spring is sprung and the buying, planting and blooming frenzy just begun.
Cold-tolerant flowers that you can plant this week:
If you just can’t wait until mid-May when our night time temperatures warm up, then grow these “almost frost-tolerant” annual plants that are safe to plant into the garden right now. Remember to harden off any plant you bring home from a warm greenhouse by letting it sit outdoors under the protection of a roof or overhang for a few nights. As with any newly planted annual, run outside and cover the young things with an old sheet or newspaper tents if frost is predicted. These three bloomers can handle our cold spring nights but not freezing temperatures.
Butterfly flower or schizanthus: For some reason this colorful annual, also called Poor Man’s Orchid, is hard to find at garden centers but local nurseries know how it can tolerate our cool, April weather and are now offering it to their more knowledgeable customers. The orchid-like blooms come in brilliant combinations of pink, crimson and violet with rich gold veins in the flower petals. All this color makes schizanthus a spectacular annual for hanging baskets, window boxes and container gardens. If you’ve been impressed with the full and flowery hanging baskets in Victoria, B.C., then you’ve been impressed with schizanthus. The reason to buy it now is because it loves our cool, damp weather, especially when protected by frost and rain by an overhanging roof or when grown close to the house.
The garden gossip on this exotic show-stopper is the length of the show. Schizanthus have a short life span so it is difficult to keep this plant in flower until September. I plant it in April, enjoy it until July and then when the weather finally heats up I just replace these Butterfly Flowers with coleus, zinnias or some other heat-loving annual. Did I mention how much the hummingbirds love it?
Lobelia – grow in shade, sun or part sun: I’ll always have a soft spot in my heart for lobelia as it was one of the first flowers I ever grew from seed as a nerdy 12-year-old. I started the seeds under the light of my fluorescent desk light. Although lobelia seeds are super tiny, they are surprisingly easy to grow.
Look for some intense new colors of lobelia available this spring at local nurseries. Deep purple, lavender, pure white and the ever-popular navy blue lobelia come in compact forms, trailing varieties and edging varieties perfect for bordering a walkway. Like schizanthus, this annual thrives in our cool spring weather and will take full sun or partial shade. Unlike schizanthus, lobelia plants can be kept in bloom a full six months if you keep them fertilized and well-watered. I like to use the pure white varieties next to the intense colors of begonias in a window box that gets very little sunlight. The white flowers really light up the shade and put brighter colors in the spotlight.
There are two newer lobelias available this year from Proven Winners. Heavenly Lilac is a deep purple while the more compact Lavender Bush is lighter in color with a more tidy growth habit. Both tolerate full sun and warmer days than previous lobelia varieties making them perfect for mixed baskets that are shaded in the morning but then get blasts of hot afternoon sun.
Lobularia: Snow Princess is the new queen of the container kingdom.
The classic lobularia or sweet alyssum is another cool-weather favorite that will reseed and also tolerates hot, dry summer conditions in Western Washington. I let sweet alyssum reseed itself each spring in the gravel courtyard of my English-style garden – but be warned that although you may purchase sweet alyssum in shades of purple, lavender and pink, it reverts back to white when allowed to drop seeds and resprout.
This year there is a much-larger, much-improved and much-better lobularia on the market. It is called Lobularia Snow Princess. An international winner of innovation awards for new plants, this super alyssum from Proven Winners is sterile, which means instead of putting energy into making seeds, it funnels all its growth into flower production. But this ambitious bloomer is no princess when it comes to growth habit. She’ll elbow her way over smaller plants, stealing real estate in pots, baskets and flower beds with an abundance of pure white blooms from April until October. Just one plant filled a large pot on my patio last summer and I never had to deadhead, prune or fuss with the frilly cloud of white flowers. Give Lobularia Snow Princess plenty of room and water and you’ll love this low-maintenance plant. Does well in full sun or partial shade and you can plant it outdoors right now as Lobularia is more cold-tolerant that other annuals.
Marianne Binetti is the author of “Easy Answers for Great Gardens” and eight other gardening books. She has a degree in horticulture from Washington State University and will answer questions from her website at www.binettigarden.com.