Q: Can you cut back a bleeding heart after it has bloomed? It starts to turn yellow and gets somewhat yucky looking as the summer goes on, but I'm afraid to cut it and ruin it for next year.
A: Yes, you can certainly cut back a bleeding heart as soon as it yellows, but I must admit, this is a little early for that to be happening. Usually they last until the heat of July sets in. Whenever it gets unsightly, feel free to clean it up. Cutting it back won't harm next year's growth or flowering.
Q: My hibiscus plant needs help. It has been exceptionally beautiful and prolific for about six months, and I have enjoyed every lovely blossom. Lately the leaves begin to turn yellow and eventually drop off. Soon, if this keeps up, I will have no leaves at all. Those that I still have, however, are dark green and healthy-looking.
Twice I have sprayed the plant with insect spray, giving it a good soaking. I continue to see leaves turning yellow, although not at quite as fast a rate.
Please help me and tell me what I can do to preserve this plant that brings me such joy.
A: Hibiscus leaf yellowing is normal for us Northerners who must keep their hibiscus plants indoors over the winter.
Are you giving the plant enough direct light? The plant needs four to six hours a day, and the sun has been moving higher in the sky since mid-December.
Winter is the time for some rest after blooming so well. In winter, don't fertilize as much and cut down on watering.
Begin a spring into summer care program now. The plant will bloom on new growth, so if you have any pruning to do, do it carefully with that in mind.
Start a regular fertilizing schedule. Every week at half-strength is fine. Use a blooming houseplant fertilizer that has a low-nitrogen formula. High nitrogen will grow beautiful green leaves, but not promote flowers.
If repotting is needed, spring is the time to do it. You want to do it when the plant is growing, not dormant.
Give the plant a shower bath once a week if you can. It really will revive the plant. Cover the pot with aluminum foil or slip it into a plastic bag so the soil doesn't splash out of the pot, and shower the plant with barely warm water.
If you have a hand-sprayer, be sure to wash the underside of leaves. (In summer, you can do this outside, but in cold months, do it in the tub or shower.)
You certainly could have bugs, but you didn't mention any damage. The usual culprits on hibiscus are spider mites and mealy bugs; both can be fought with an insecticide with soap, repeating spray every 10 days to attack the pests as they hatch. Safer's makes a good spray for indoor use. Look for a slight webbing or rusty powder on the underside of leaves. Safer's Soap Insecticide is great for indoor or outdoor use.
A thorough spraying with cold water will dislodge them, too. Hose the hibiscus down every week. Undersides of leaves are the usual hiding places for these bugs, so spray thoroughly.
When night temperatures are consistently 50 degrees, you can gradually take the plant outside, where it can remain until the temps drop in the early fall. Spraying outdoors in summer is much easier than doing it in the bathtub.
Q: I transplanted three lilac plants (one is an offshoot of my grandmother's) four years ago. They all bloomed the first year but then never again. Last year, after consulting the local nursery, I pruned them down only to get two blooms this year. I am pretty sure I didn't prune them after blooming their first year here, because I wanted them to grow taller, quickly. I am assuming that is why they didn't bloom the following years. How and where should I prune them now to generate blooms for next year?
A: Don't worry, be patient. Lilacs are worth the wait!
No lilac will bloom before its time, and most varieties won't bloom until they reach at least 3 to 6 years of age. The first three years are spent growing and developing and adjusting to the shock of being uprooted and replanted. Only then (and only when they are good and ready) will they produce their first blooms. When they finally do bloom, the first few years can be far less than spectacular.
Plant them in full sun for the most spectacular blooms.
Pruning should be done, if ever, right after bloom. Midsummer is too late because the plant is already setting buds for next year's blooms on the old wood. Be patient and go easy with the pruners.
Q: I have a gravelly slope at the top of my driveway where pricker bushes are growing. Eventually I hope to terrace the area to grow blueberry and raspberry bushes. I have cut and pulled at the prickers to no avail and would like to know how to get rid of them. They are starting to poke up through the asphalt driveway. I am leery of using a weedkiller if I want to grow other plants there. Also, they are near the septic system and I don't know if weedkillers would affect that.
A: Those pricker bushes are devilish things to get rid of, but I'm afraid that a weedkiller (such as Roundup Grass and Weed Killer) would be your best bet since you have already tried cutting them back.
I called the nice people at Scott's, who make Roundup, and they say that if you use one of their slightly milder weed and grass killers, not the heavier brush killer or concentrates, you would be safe in replanting the area with eatables after waiting three days. Use with caution and read the caution label completely before using.
Scott's says the septic system isn't a problem. They would be worried if there were a water source, like a well, near an application area. Spring is a good time to use a product as the weeds are growing well. Keep after them, as some weeds root below the surface and may not be killed on the first try.
This week's dirt
A Fourth of July hint — keeping bugs at bay: Look what Bounce laundry softener sheets can do for you besides softening clothes in the dryer. Tie a sheet of Bounce through your belt loop when outdoors during this terrible mosquito season — kids, too! Try it tied on the dog's collar to keep him bug-free, too.
Put a sheet of Bounce in your pocket when gardening or working out in the yard to keep yellow jackets away. Yellow jackets will just steer clear of you.
Bounce will also chase ants away when you lay a sheet near them. Try it in the kitchen.
Bounce won't kill bugs, but bugs do avoid it, and it's safe around kids and pets and foods. It's also cheaper than the insect repellents you spray on the skin.
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North Shore Gardener by Barbara Barger of Beverly is a feature of Friday's Lifestyles section. Reach Barbara by e-mail at nsgardener@comcast.net or write to her c/o Salem News, 32 Dunham Road, Beverly, MA 01915. Previous North Shore Gardener columns can be found at www.nsgardener.com.
