June is the month of roses. The rose is still America’s favorite flower, even though the formal rose garden featuring demanding hybrid tea roses with long stems has been replaced by more disease-resistant landscape roses with a more shrubby growth.
Here are some things to know about growing roses in Western Washington:
You can grow roses in partial shade: Roses do best in full sun, but there is a dark pink, fragrant roses called Zephirine Drouhin that tolerates shade. I ordered this old-fashioned climbing rose years ago from a mail order company and it blooms each June entwined with a Nelly Moser clematis in a part of my garden that receives only a few hours of afternoon sun. As a bonus, it has a strong, sweet fragrance and — to make a painless point — this climbing rose is thornless.
You can add new roses to your garden in the summer months: Nurseries now offer more roses for sale potted up in containers and this means you can see them in bloom before you buy and transplant them from the pot into your garden all summer long. If the rose for sale at the nursery is growing in a container 5 gallons or larger, you can enjoy it as a potted patio plant all summer or transplant it into the ground any time of year.
Our cool climate is picky about petal count: Many rose varieties will list the number of petals per flower — this is because in cool, wet climates such as Western Washington a low petal count is best, to avoid balled up blooms that fail to open. In dry climates more petals are better as the bloom will last longer.
Groundcover roses will block weeds on slopes but also grow great in containers: Low-growing roses (under 3 feet tall) can spread out with enough vigor and disease resistance to block weeds and cover slopes, but these sprawling roses also do well in large containers as patio plants that will bloom for years in the same pot. The most common groundcover rose is the Flower Carpet series that is available in a rainbow of color choices. In our climate, the coral variety of the Flower Carpet line seems to do the best in Western Washington, and the soft pink variety called Apple Blossom also blooms well.
Not all roses need constant feeding: The traditional hybrid tea rose is a hungry, greedy devil and should be fertilized several times during the growing season to keep the blooms coming. Many of the old roses, the shrub roses and the species roses can thrive without annual fertilizing. All roses do best with at least one application of fertilizer each spring. A slow-release plant food such as Osmocote can be applied once in May for yearlong feeding. Dehydrated alfalfa and fish fertilizer are other options for fertilizing your roses.
You can control rose diseases with good cleanup and pruning: In our climate, black spot and powdery mildew are the fungus among us that most often infects rose plants. Pruning back old growth in early spring and raking up fallen leaves and adding fresh mulch on top of the soil is an effective way to control overwintering disease spores. In the summer, remove infected or yellow leaves immediately before they get a chance to spread spores all over the plant.
You can improve your sad or ugly roses with compost — but you don’t have to keep the divas: The secret is the soil when it comes to growing happy, healthy rose plants and you can hit the refresh button on your rose plant by piling on the compost, moo doo or old manure every spring then poking deep holes around the root zone. Compost is not a substitute for fertilizing, so feed your roses even as you improve the soil. Ugly roses can be pruned back hard — to about 2 feet tall in the early spring when you see daffodils blooming. If a sickly roses does not respond with healthy new growth and satisfactory blooms after a year of pampering, then get tough and yank the ungrateful diva out of your garden. A fresh start with a new rose plant is a great way to celebrate summer.
June is the month to visit the rose display gardens at Point Defiance park in Tacoma, the Schmidt Mansion in Tumwater or the Woodland Park Zoo in Seattle and look for a new variety of rose for your own garden.
Marianne Binetti has a degree in horticulture from Washington State University and is the author of several books. Reach her at binettigarden.com.