Does your sago palm have some white stuff on the fronds? Some have described it as a "snow-like dusting" or even "a white fungus-like film." In most cases, the problem is an insect called cycad scale.
Cycad is the scientific name for sago palms. The technical name of this troublesome insect is Cycad aulacaspis scale, also known as Asian cycad scale.
These insects were inadvertently brought here from Thailand and were first found in Florida in the early 1990s. In Texas, cycad scale problems emerged in 2001. When I discovered the insects on my sagos, I treated the condition by using malathion on the entire plant. I haven't seen the problem since.
Cycad scales are easily controlled with insecticidal sprays or a homemade organic scale control. However, the average homeowner, often fails to notice the condition and take action before the infestation is beyond repair.
If you have serious infestation, prune off fronds that are heavily coated with cycad scales. To help prevent re-infestation, dispose of the cuttings in double-sealed plastic bags. For the earliest onset of these pests, chemical controls like malathion work wonderfully. Other products for control are acephate or carbaryl (Sevin).
Organically, there are two ways to get control. You can use a dormant oil spray in December and January, or you can use our homemade version. The formula listed below came from our friends J.C. and Carter at Condon Gardens Landscaping.
Mix in a gallon sprayer:
- 1 ounce of molasses (Medina & GardenVille molasses are great examples)
- 1 ounce of garlic oil (Garlic Barrier is the most widely recognized)
- 1 ounce of liquid seaweed (GardenVille Liquid Seaweed is well known)
- Then fill the rest with water.
If you have an inordinate amount of insects, such as aphids or whiteflies, you can also mix in a couple of ounces of liquid pyrethrum and keep the spray organic, but create an instant "knockdown" of heavy infestations.
J.C. and Carter both agree that if you just use the mixture occasionally, not only do you keep any insects from generating damaging populations, but you get some natural disease control on landscapes with the garlic oil and seaweed. If you were wondering about the need for the agricultural types of the garlic and molasses, the reason is pretty simple: The agricultural ones haven't been overly processed, and all the natural sugars and microbes are still there ... they're needed in the overall scheme of organic controls.
Obviously, you are not going to find all these products at your average garden center, mass merchandisers or big-box store. I've listed below some of the many independent nurseries and garden centers that carry all of these products. If any of them don't have one of the noted products on the shelves, they can easily get them in a matter of days from local distributors.
- RCW Nurseries (on Highway 249 at Beltway 8)
- Southwest Fertilizer (on Bissonnet at Renwick)
- Cornelius Nurseries (any of three locations)
- ABC Country Store (near Katy High School)
- Buchanan's Native Plants (on 11th St. in The Heights)
- Maas Nursery (5511 Toddville Road in Seabrook)
Licensed applicators, such as pest control companies or certified landscaping services, can also apply products containing dimethoate, pyriproxyfen and dinotefuran.
The best way to prevent cycad scale infestation is to check your sago palms every week or two. Look for anything out of the ordinary, and catch these pests in their earliest stages.