Monday, October 23, 2017

Sweetgrass - Mealy Bugs

Horticulture Hotline 10/23/17
By Bill Lamson-Scribner

Question: Bill, I have a white, sticky, fuzzy fungus on my Sweetgrass plant. What can I do? I am retired now and my wife expects me to help her keep a nice yard when I’m not fishing or emailing my friends.

Answer: Congratulations on your retirement! Good luck with your fishing!

Your Sweetgrass plant most likely has a soft body, sucking bug called a mealy bug attacking it. Mealybugs are like aphids, scale, white flies, the “nasty rascal, the chinch bug”, lace bug and other sucking bugs in that they suck plant juices or sap from the host plant.

I was surprised when I first saw mealybugs on Sweetgrass. I usually associate mealybugs with plants grown inside buildings, homes (interior plantscapes) or greenhouses. I usually think of ornamental grasses as being pest free – wrong!

As with any sucking bug, you want to get the situation under control fast, or you will have the secondary problem that looks way worse than the fuzzy, airy mealybugs. The secondary problem is the dreaded sooty mold.

Sooty mold is the black mold that grows on the excrement (poop) of certain sucking bugs. Have you ever seen a black gardenia (from white fly poop) or crepe myrtle (from aphid poop)? Certain insects have a very short digestive track and they are drinking sap from a plant that is pressurized. The sap goes in their mouth and out their behind very rapidly covering the plant with a sugary substance (often called honey dew) that this mold grows.

In human terms, if you could connect your mouth to, let’s say, a keg of beer or maybe a soft serve ice cream machine at some point the beer or ice cream would be coming out of somewhere (nose, ears, …) leaving a mess. Insects have hardly any digestive tract to slow things down.

A very effective way to control these mealybugs, while not hurting the beneficial insects, is to use an insecticidal soap. Also drench the area around the Sweetgrass with Dominion.
Dominion is a long term systemic insecticide that will free you up for more time fishing.   

Always read, understand and follow product label. The product label is a Federal Law.
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Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations 481 Long Point Rd in Mt. Pleasant (971-9601), 3325 Business Circle in North Charleston (760-2600), or 606 Dupont Rd, in Charleston (766-1511). Bring your questions to a Possum’s location, or visit us at You can also call in your questions to “ The Garden Clinic”, Saturdays from noon to 1:00, on 1250 WTMA  (The Big Talker).