Grumpians are well aware of the many over-the-top promises made every day on TV, radio, newspapers, and our beloved spam. That’s why I’m so happy to be continuing that fine tradition right here. I can’t answer ALL of your questions in one blog, obviously. But if a misleading title can trick you into reading further, you just may find out what’s gone wrong with your crepe myrtle, your lawn, your roses, and the old lady next door who’s always dancing by herself.
With the possible exception of why rosarians shouldn’t garden in the nude, no garden issue consumes us more in the summertime than crepe myrtles. Almost everybody has them. Almost everybody has questions, like these:
“When standing under my crepe myrtle, it sounds like rain is falling, but the sky is blue. Why is that?” – Neil
Grumpy says — Well, Neil, the first thing I’d check is whether your crepe myrtle is planted under the open window of a second-story bathroom. If that’s not the case, what you’re probably hearing are drops of sweet honeydew secreted by aphids sucking juice from the leaves. When this honeydew accumulates on the leaves, ugly black mold often grows on it. A safe way to give aphids the heave-ho is to spray the undersides of the leaves with all-season horticultural oil or insecticidal soap.
“Your Excellency, I live on the beautiful inland sea of Puget Sound [near Seattle]. My ‘Zuni’ crepe myrtle is planted in a container on a sunny spot on my deck. It’s about 4 feet tall and looks healthy, but has no blooms yet. Will it bloom next year?” — Susan
Grumpy says– Gee, thanks, Susan, for making us the rest of us feel cursed and inadequate. Do you fly in planes with Richard Branson and lunch with Michelle Obama too? ‘Zuni’ is one of the Grump’s favorite crepe myrtles, forming a vase-shaped shrub to 10 feet tall with gorgeous lavender-purple blooms. Look at it here in Helen Yoest’s garden in Raleigh. When a crepe myrtle blooms depends on two things — genetics and temperature. Some types, like ‘Natchez,’ bloom quite early. Others, like ‘Watermelon Red,’ bloom later. High summer temps speed up blooming. If it doesn’t reach 90 degrees in lovely Puget Sound until July, your crepe will bloom later. Strangely enough, when I was in Seattle a few weeks ago, it was 103. Now you know how the rest of us live.
“My fairly young ‘Natchez’ has flowers so large they bend the spindly stalks nearly to the ground. It’s worse once they’ve gone to seed. Any suggestions?” — Lalagigi
Grumpy says — Oh, named after a Pacific island, are you? Flower heads bending over spindly branches usually results from improper pruning, called “crepe murder,” in which an uninformed yet well-meaning person with absolutely nothing else to do goes out in winter or spring and cuts the trunks into ugly stubs. Each stub then sends out a forest of long, whip-like branches too weak to hold up the flowers. The solution is to stop murdering your myrtles. Don’t cut back the main trunks and the blooms will be held high. You can cut off the seedheads if you wish.
“Yo, Grump, got these low-to-the-ground, brown mushrooms in my yard. I didn’t plant them and I don’t want them! What are your suggestions for ridding my lawn of these fungi?” — Rick
Grumpy says — Well, you could black-top your yard. That’d solve the problem for sure. Mushrooms are the only visible sign of active fungi in the soil that decompose organic matter, like dead tree roots. There is nothing you can do to get rid of the mushrooms until they’ve fully digested the organic matter — unless you love the smell of black-top in the morning.
“Now that the blooms of my French hydrangeas have faded, should I cut them off? There is new growth on the plants.” — Julia
Grumpy says– Yes, it’s OK to remove the spent blooms. But don’t cut back the new growth. Many hydrangeas produce flower buds for next year on this growth. Cut it off now and no flowers later. Exceptions are repeat-bloomers like ‘Endless Summer,’ ‘Pennymac,’ and ‘All Summer Beauty.’
Gourds and Pumpkins
“Is it too late to plant the decorative gourds and pumpkins? I don’t have any seeds, but I guess I can get them at the nursery.” — Sylvia
Grumpy says — No, you can’t, because it’s too late to plant them now. Pumpkins and gourds require a long growing season to produce. You’ll have to wait to plant next spring. In the meantime, wait until it’s dark and swipe some pumpkins from your neighbor’s garden.
Shrubs for Screening
“I need a plant that would make a good screen between two homes. My driveway and the neighbor’s driveway have 5 feet between them. I would rather not look into his garage every time I leave the house. Do you have any suggestions for this spot that gets full sun?” — Jenny
Grumpy says– I believe it was Robert Frost who wrote, “Good hedges make good neighbors.” Since you live near Nashville, you need evergreen shrubs that like your climate and also take pruning and shearing quite well, so that you can control their size. Here are some suggestions: ‘Hicks’ Japanese yew (Taxus x media ‘Hicksii’); ‘Nellie R. Stevens,’ ‘Needlepoint,’ ‘Robin,’ ‘Sky Pencil,’ or ‘Oak Leaf’ holly; ‘Gray Gleam,’ ‘Skyrocket,’ or ‘Spartan’ juniper; and ‘Bright ‘n Tight’ cherry laurel.
“I had a recipe for a spray to control mildew on roses, but my grandson used a hole punch on it and now I can’t see all the amounts. How much baking soda do I use?” — Denise
Grumpy says– A common recommendation is to add 1 tablespoon of baking soda to a gallon of water. The alkaline nature of the baking soda makes leaf surfaces inhospitable for the fungus. You may also want to to mix in 1 tablespoon of horticultural oil to help the spray spread evenly and stick.