Friday, April 20, 2018
Home and Garden

Ask Dr. Hort: Pesky leaf-eaters feast on bougainvillea

Pesky, pesty leaf-eaters feast on bougainvillea plant

Q: Could you tell me how to deal with something that is eating the leaves of my bougainvillea please? The plant is well established but has not been cared for by the previous owners. It is flowering well but some of the stems are now devoid of leaves. I would be grateful if you could tell me how I can eliminate the pest. Also, some tips on pruning this prickly customer would be useful. Julia Harris

A: Your bougainvillea, Bougainvillea spectabilis, is in need of some work, but it is a fast grower and blooms all year on new growth so pruning it way back now — perhaps to 3 to 4 feet — and fertilizing with a quality 10-0-10 should eliminate the pest problem for now and reshape your plant for the flowering season ahead. The photos of the chewed leaves show signs that one of three weevils have been feasting: The Sri Lanka weevil is white, Diaprepes is black and brown, and the blue-green root weevil is about 1/2 inch long with a curved snout. The adults lay eggs on leaves; the maggots hatch and drop to the ground, where they burrow and feed on roots, pupate (rest) and molt into adults to infect your plant or tree around April and May as you have witnessed, chewing the leaves from the outside in. So if they return, contact sprays of Conserve (spinosad) early in the morning will kill the adults. Next year, ground applications of Bayer Advanced Tree & Shrub granules (imidacloprid) applied under your tree or shrub, where the maggots would fall, will kill the adults as they emerge, hopefully finishing off the population.

Don't break your back pulling bamboo; try chemicals

Q: Recently bought a home in Dunedin and have started to put in some plants. The previous owners had planted the invasive type of bamboo, and it is sprouting all over the back and side yards. I tried pulling, digging, etc., but nothing seems to work. They are actually impossible to pull out of the ground. Linda Robertson

A: You've got a whale of a problem on your hands. Running bamboo lives up to its name, and it just can't find the finish line. The tips at should give you a plan of attack, except in and around flower beds where Roundup may kill surrounding plants. In that case substitute Fusilade II, a selective weed killer specific to grasses (bamboo is a close relative). This is a professional-use chemical you will have to purchase at John Deere Landscapes, not Lowe's or Home Depot. Roundup Pro (41 percent glyphosate) may also be purchased there. These products are fairly pricey, but they cost less than back surgery. No matter what the combination of strategies is, you will have a two- to three-year battle on your hands, but one that you can win.