Kimas Tejas Nursery

Control Those Grasshoppers Organically

Gardening in Texas can be challenging. We can go for months without rain. This lack of rain can be accompanied by searing heat that’ll make all living things seek out the shelter of shade. These two things, when combined, create the conditions for that which quivers a Texas gardener’s soul, a dreaded grasshopper infestation. Urban gardeners, while they can experience the damage of these little devils, know nothing of the heartache wrought country gardeners by the grasshoppers moving in from surrounding fields.

There are over 150 species of grasshoppers in Texas, with five species causing 90% of the damage to Texas agriculture. The Differential grasshopper is the “common” grasshopper we see the most in Texas. A lack of rain, coupled with warm temperatures is the perfect precursor to a grasshopper population explosion. Colder winter weather really does nothing to quell the grasshoppers. The ground would have to freeze three inches deep to kill their eggs that they lay underground in the fall. Two things naturally keep the grasshopper population in check. A wet spring encourages bacteria and fungi that are very hard on young grasshoppers, known as nymphs. A cold, short, and wet fall shortens the egg-laying season and allows the same bacteria and fungi to consume the grasshopper’s eggs over the winter. Since 1996, much of the state has seen below normal rainfall, leading to just the right conditions for grasshoppers to explode in population.

What’s an organic gardener to do? Even multiple sprayings of toxic pesticides will not do much to slow grasshoppers as they are migratory in nature and will only move back into the landscape after spraying. There are, thankfully, several things that the home gardener can do to protect the landscape and the vegetable garden.

• Nosema locustae – A naturally occurring spore that is coated onto bran flakes and dispersed in the landscape. The grasshopper ingests the spore when eating the bran flak. Young grasshoppers will die soon with older grasshoppers becoming lethargic and losing their appetite. Healthy grasshoppers eat the dead and dying infected grasshoppers, extending the effectiveness through the season. It’s sold under the brand names GrassHopper Attack and Nolo Bait. One pound runs around $16-18 dollars and covers one acre with 6-8 grasshoppers per square yard. Heavier infestations require more per acre with possible multiple applications. Most folks get some respite by using the N. locustae, but some say that it doesn’t work, probably because of a heavy infestation and too little spore applied.
• Surround WP – This is a highly refined kaolin clay based product. It is OMRI registered for use on Certified Organic farmland. Mix one-half pound of this very fine dry material with one gallon of water and spray on the plants. This coating on the plants makes them unattractive to insects, discouraging the insects from chewing on the leaves. It’s effect not only for grasshoppers, but other leaf-chewing insects as well. Other healthy benefits for Texas gardeners include reduced sunburn and heat stress for plants. Unfortunately, licensing for anything less than a 25-pound bag was given to Gardens Alive, a mail order company that is charging extremely high prices for this product. However, your local garden center can order some for you. A 25-pound bag will cost around $30. If interested, have them call the nursery at 512-303-4769 and I’ll give them the contact information on where to order.
• Floating Row Cover – This product is very thin spun polyester sheeting that works by providing a physical barrier around the plants. You use this cover to make a “tent” over your vegetable plants, being careful to secure the edges so the grasshoppers cannot crawl underneath. While not attractive for your ornamentals, it is very effective in the vegetable garden. Sunlight and water comes through, but the bugs stay out. For ease of watering, consider installing drip irrigation. The cost is around four cents per square foot, available in widths up to twelve feet.
• Insecticidal Soaps – For a more immediate kill of young grasshoppers use this product. The fatty acids of these soaps dissolves the exoskeletons of young grasshoppers. Please note that these soaps also kill beneficial insects, so use sparingly.
• Birds – For those of you in the city, encourage a healthy bird population in your landscape. For you country dwellers, chickens and guineas are grasshopper-eating machines!