The second week in June means your roses have bloomed and are looking for more food for the second wave of flowers. Fertilize roses, perennials and annuals this week. Anything growing in a container, from lettuce to petunias needs, fertilizer this month as the days are longer and the plants are working overtime producing new growth.
This also is a good week to pinch back any leggy petunias and prune back sedum “Autumn Joy” plants to one-half their size. By pruning succulents such as sedum now, you will encourage branching and more upright plants that will not need staking. Shear back rock-garden plants such as creeping phlox, basket-of-gold and candytuft that have finished blooming. If foxgloves or delphiniums have bloomed, cut back the main stalk now, and the plants will send up side shoots for an encore of color.
And now some good news: New hydrangeas work like magic in Western Washington gardens.
Cool, wet summers are perfect for the new reblooming hydrangeas, and the fact that you can harvest and enjoy the first June blooms and be rewarded with even more flowers all summer long makes hydrangeas a shrub of incredible value.
No other plant will give a landscape more flower color in shaded areas year after year without replanting. The breeding breakthrough that made hydrangeas the comeback kids of the summer scene is the fact that once you remove one of the balls of bodacious blooms, it tells the entire shrub to get busy and make more flowers.
All this snipping and picking also keeps these new hydrangeas more compact so they can be enjoyed in containers and close to the house without blocking the light from first-floor windows. Check nurseries this week for the new dwarf hydrangeas, Pee Gee hydrangeas and reblooming hydrangeas.
Do’s and don’ts for happy hydrangeas:
Do choose from the reblooming varieties. “Endless Summer” is the brand name that started it all, but you also can find big-leaf hydrangeas recommended by the gardening gurus Proven Winners (provenwinners.com). Those reblooming varieties come with names such as “Let’s Dance” (buds are extra cold-tolerant), “CityLine” (compact plants for smaller yards), “Edgy” (variegated or bi-colored blooms) and “Abracadabra” (magical black stems).
Do choose a location protected from the hot afternoon sun. Heat will wilt these shrubs even if there is plenty of moisture in the soil.
Do harvest or remove the blooms if you want more new growth and late summer color.
Don’t fret about the confusing choices and varieties of hydrangeas. They all do well in our climate. Big-leaf hydrangeas or hydrangea macrophylla give the most color.
Don’t forget that hydrangeas can be used for a summer screening hedge. Choose one of the “bracted” hydrangeas such as “Little Lime” or “Limelight” with pale green and white blooms on more upright plants. These large hydrangeas are more tolerant of winter cold and summer heat than the big-leaf hydrangeas.
Don’t plant your hydrangeas in deep shade if you want maximum blooms. On the north side of a house, your hydrangeas will look healthy but produce few flowers. On the east side of the house or in a woodland garden where the shrubs get four to five hours of filtered sun, that same plant will be covered with blooms.
Don’t forget to water your hydrangeas during droughts and improve the soil with organic matter when you add them to the garden. Hydrangeas need the most water the first summer after you plant — this is when they are building a root system.
Don’t expect your big-leaf hydrangeas to be the exact same color as they are at the nursery. The more acidic your soil, the more blue the blooms. Our soil is naturally acid. Adding aluminum sulfate to the soil around your hydrangeas will turn them pink or purple, but this might take several seasons to work.Marianne Binetti has a degree in horticulture from Washington State University and is the author of several books. Reach her at binettigarden.com.