Print

Email story

Comment

Letter to the editor

Asian pest decimating the sago palm

By Yvonne Swanson, Special to the Times
Published February 23, 2008

It's surprising that many bay area garden centers are again stocking sago palms, those deep-green cycads that look so lush and exotic in the landscape. Before you invest in one of these expensive tropicals, heed the warning of horticulture experts: Don't buy it!

King and Queen sagos are the target of Asian cycad scale, an airborne insect infestation that traveled from Thailand and southern China, possibly through imported cycads. It was first discovered in the mid 1990s in Miami, and has moved rapidly throughout the state.

The scale insect will cover a plant, insert its strawlike mouth into the flesh and start a feeding frenzy. A white covering or scale forms over the insects, which can completely coat a medium-sized sago in just a few months. Left untreated, the plant will die within a year.

"It's such a horrible death. They get sucked to death, covered in scale," says Jane Morse, a Pinellas County commercial horticulture agent. "I would never recommend putting them in the landscape."

Treating a sago is no easy task. There can be layer upon layer of up to 3,000 scales per square inch of the plant, and the scales can cover roots as deep as 2 feet into the soil.

You can use a strong spray of water to slow infestation on small sagos, but it's more likely that you'll need to use a commercial product every other week to keep the scale under control.

Numerous horticultural oils and pesticides/insecticides are available, and the garden center where you purchased your sago will probably be happy to sell them to you (don't forget to buy a sprayer, too).

Officials are hoping that a predatory beetle and wasp, which are being released into the environment, will attack the scale, but this biological approach will take years. In the meantime, be prepared to provide lots of TLC and chemicals if you have sagos in your yard. If you're still thinking of buying one, consider yourself warned!

Yvonne Swanson is a freelance writer in St. Petersburg and a master gardener for Pinellas County.

[Last modified February 21, 2008, 18:06:49]