Poison sumac is not common in Georgia

A: I bet it is false oleander scale. This sap-sucking insect attacks boxwood, magnolia, aucuba, oleander, ivy and many other plants. Heavy infestations can cause leaf loss and general decline of the infested plant. Since immature crawlers are present throughout the year, this scale does not have an optimal timing for insecticide applications. Several applications of horticultural oil or other insecticide may be necessary to reduce heavy populations. My advice is to be hawk-eyed and prune out any affected branches on your boxwoods. With luck, you can control the pest without resorting to spraying.

Q: I planted some dahlia tubers late in May. They came up but were leggy and fell over. I staked them but wondered if I planted too shallow. John McIntosh, Atlanta

A: Dahlia tubers have a remarkable ability to anchor themselves even if planted too high. The question now, though, is whether they survived the cold weather this winter. Wait until mid-April to see if any growth appears. If you see greenery, you can stake them or replant a bit deeper.

Q: I planted four hibiscus sabdariffa plants last year. They got much larger than I expected but I propped them up with stakes and twine. They are now either dead or dormant. Do I pull them up? Sherry Bilodeau, email

A: Hibiscus sabdariffa, aka roselle or Red Zinger hibiscus, is not cold-hardy in Atlanta. Our cold weather has probably given the stems a big whack, but they MIGHT sprout again from the roots. Cut them back to a foot tall and cover each one with a cardboard box. Put a rock on the box to hold it down until things warm up in late March. Uncover the plants and see what happens.

Walter’s email address is georgiagardener@yahoo.com. Listen to his comments at 6:35 a.m. on “Green and Growing with Ashley Frasca” Saturday mornings on 95.5 WSB. Visit his website, www.walterreeves.com, follow him on Twitter @walterreeves, on Pinterest, or join his Facebook Page at bit.ly/georgiagardener.

ncG1vNJzZmivp6x7orbCZ5qopV%2BhtqexjqGmpp1dnK6zsMSnZqmnmai8r3nSrqSam12ewG66zq1knKedoryvecinZKCdn6e0qq2OjIGAiWd%2Fg5qatX17f3yHi5iHpLODhpKFf4J8