The last week of March is a call for color as blooming shrubs and flowering trees burst on the scene. Add to this show the emerging buds of tulips, iris and rock garden plants and the stage is set for the grand performance of a Northwest spring.
Here are the most-asked questions about the most popular plants this time of year:
When should I fertilize my roses? They are showing lots of new growth and have been very healthy, but I noticed fewer flowers last year. These are the tough shrub roses that turn into large shrubs in my garden. – P.G., Auburn
Your roses are waking up and starving right now. Heavy feeders like roses need more than just compost or manure to keep them happy. Use an all-purpose rose food or a complete fertilizer with numbers like 5-10-10.
I have over-wintered some geranium plants indoors, and they survived, but are leggy and rather pale. When can I move them back outdoors? – T.T., Tacoma
Geraniums, fuchsias, tuberous begonias and other frost sensitive plants that survived the winter indoors or inside a garage or basement cannot go back outside unprotected until all danger of frost is past. I know they look like ugly ducklings right now, but leggy geraniums can be cut down by one third this month and placed near a bright window. Fertilize at half the strength recommended on the label to wake up your geraniums slowly. You don’t want to encourage a flush of quick growth while the plants are still stuck indoors. In a few weeks, begin to harden off the tender plants by moving them outdoors during the day and then bringing them in at night.
I have a lilac bush that suffered in the windstorm and is split almost in half. I never got around to pruning off the damaged branches. Now to my surprise the branches are sprouting. Should I not prune it after all? Will it bloom even though the branches are broken? – A reader, via email
Spring is a series of small miracles and sometimes even downed trees will bloom in a final gasp at life. I would wait and see if your broken lilac branches flower, then enjoy them as cut flowers. Once the plant is finished blooming it will be ready for a trim or drastic makeover with the pruning saw. Lilacs are one of the flowering shrubs that can be pruned to within a few inches from the ground and will sprout with fresh growth. You can also prune back forsythia, quince, spiraeas, buddleias and smoke trees to within a few inches of the ground. It may take a few years before heavily pruned shrubs bloom again.
When should we start seeds indoors and which ones do we start? – R. D., Buckley
Each variety is different, so there is no easy answer here. Read and follow the instructions on the seed pack using May 10 as your date for when “all danger of frost is past” and April 1 as your date for “when soil can be worked” and count backward or forward as the instructions suggest. For more specific information about your gardening question, contact me by going to my website, binettigarden.com.
Marianne Binetti is the author of “Easy Answers for Great Gardens” and eight other gardening books. She has a degree in horticulture from WSU and will answer questions from binettigarden.com.
9 a.m. March 31, Windmill Gardens, 16009 60th St. E, Sumner.
Topic: “Color, Color, Color,” learn how to plant 4 seasons of color. $5.
Go to windmillgarden.com or call 253-863-5843 for more information.