At this time of year when many shrubs are blooming or just past their bloom cycle, gardeners are wondering how to care for them, when or if to prune them and more.
You’ll find answers to these questions and many more in Marianne Binetti’s book, Tips for a Carefree Landscape. Here are a few of the most asked questions about Flowering Shrubs along with her helpful answers for more easy-care gardening.
Q: I bought a hydrangea bush when it was in bloom, and the flowers were pink. Several years have passed and now the flowers are blue. How can I get back my pink hydrangea blossoms?
A: Hydrangea definitely have a problem with gender identity. In acid soil, they bloom a bold and masculine blue, but put the same plant in a more alkaline soil and it takes on feminine traits and turns pink. If you really want to have a pink bloomer, sprinkle dolomite lime around the lime around the roots this fall. Use one shovelful of lime for a 4-ft tall hydrangea shrub. It may take several years of lime treatment before it turns pink. At least your blue hydrangea has taught you something about your soil. Now you know that you garden with soil that is naturally acid. Plants like azaleas and rhododendrons thrive in acid soil.
Q: Do I really have to pick off all the dead flowers from my rhododendrons, lilacs and other flowering shrubs?
A: No. Your shrubs will still bloom if you don’t get around to removing all the spent flowers. You may not get as many blooms or as much new growth, but I’ve never noticed a big difference between rhododendrons that were cleaned up after blooming and rhodies that went natural. Removing the old flowers is not only a tiresome, messy job, but unless you do it carefully, you could break off the new tip growth along with the spent flowers. If your shrubs are large and viewed from a distance, the fading flowers should be left alone to die a quiet death. Save your precious time and energy for more crucial gardening tasks.
Q. When should I prune my flowering shrubs?
A. As easy rule of thumb is: If it blooms in the winter or spring, prune it soon after the flowers fade, or if you need cut flowers, go ahead and trim it up when it’s blooming. If it blooms in the summer or fall, prune in early spring. Then the shrub will have plenty of time to form new buds before bloom time. NOTE: one exception to this are the repeat-blooming hydrangeas such as Endless Summer. Those should be pruned in late summer to allow time for new growth. Otherwise, if you wait until spring, you may end up cutting off new blooms.
A few other pruning tips from gardening expert Marianne Binetti . . .
- Look for thick stems emerging from the center of the shrub. Remove a third of the thickest branches, cutting as close to the ground as possible. This will encourage fresh side shoots to pop up with more energy
- Clean up any small, weak shoots that are growing toward the center of the shrub.
- If you need to severely cut back a shrub because it’s taking over the space, the best time to cut them right back to the ground is in late winter when the shrub is dormant. Don’t expect instant recovery when you massacre and overgrown shrub though. It may be a year or two before it begins to bloom again.
If you have other pruning or landscape related questions, send them along! In the meantime, check out Marianne Binetti’s website for more helpful tips, tricks and ideas.