Q: Do you know reasons why my gladiolus flowers would come up fewer and fewer each year? I was expecting them to multiply! Niecey Rogers, email
A: In my observation, it's usually it's because there's too much competition from new bulblets (technically they are cormels) around the original bulb. It's best to dig gladiolus bulbs each fall and separate the bulblets that cluster around the mother bulb. Of course the bulbs could be growing in wet or hard soil, which would also cause their numbers to diminish.
Q: Could you please tell me how to kill weeds in a moss bed? Chris Blount, email
A: Pulling them individually is the only option. I spoke to a gardener recently who tried spraying glyphosate (Roundup, etc) on weeds in his moss bed. He reported that the non-selective weedkiller killed his moss just as quickly as it destroyed the weeds.
Q: I’m growing potatoes in a wire cylinder that I gradually fill with layers of compost and shredded leaves. As the shoots appear above the mix, should I completely cover them with another layer or should I let them grow a little taller and put the mix around the stems? Chuck Rigdon, Lithia Springs
A: Growing white potatoes above ground is an easy way to garden in spring. To your question, you need to leave some of the leaves uncovered. I usually cover the stems with loose compost but leave the top four leaves uncovered. Details on the technique at bit.ly/potatotire.
Q: We bought a ‘Biloxi’ crapemyrtle last fall. It has four stems and is seventeen feet tall. How should it be trimmed? David Massey, Canton
A: 'Biloxi' crapemyrtle has pretty lavender flowers and the exfoliating bark is beautiful in winter. It's one of the larger crapemyrtles, eventually growing to twenty feet tall. If it were mine, I'd keep the four vertical trunks and prune away lower limbs up to eight feet. You can then allow the top limbs to grow however they wish without needing to prune them again.
Q: What is the best systemic insecticide for ambrosia beetle control on crepe myrtles? I was using Isotox but my bottle is all gone. Rick Parks, email
A: Systemic insecticide will not kill ambrosia beetles. The female beetle bores through the bark and into the heartwood of crape myrtles. Though systemic insecticide may be in the cambium layer of the plant, the beetle does not ingest this vascular tissue: she quickly bores through it and is not exposed to enough insecticide to hurt her. The best way to protect crape myrtles from ambrosia beetle attack is to thoroughly spray the bark with cypermethrin, permethrin or deltamethrin four times at two week intervals in spring. Beetles begin to be active in February so don't delay your sprays.
Q: When is the best time to scalp zoysia lawn after winter? Shawn Malone, Dekalb County
A: You can hasten the greenup of bermuda and zoysia lawns by removing the dead leaves after vigorous growth has begun. When your lawn is at least 50% green you can set your mower to cut the grass a half inch below the normal cut. Do not scalp a lawn that is not showing lots of green.
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