Whether your lawn plants cover yards or a few square feet on the deck, then they are exposed to thrips infestations. Thrips are slender, winged insects with the nasty habit of piecing plant tissues to suck their mobile contents, including chlorophyll. Affected leaves develop a tell-tale silvery sheen and dark speckling in the insects’ waste. Removing thrips does not remove the sheen in an infested plant, however it will not prevent the wind in spreading the insects. Although chemical insecticides are largely ineffective against thrips, several organic alternatives control them fairly well.
The Cold Water Treatment
If your lawn is small, removing thrips may be as simple as turning your hose’s spray nozzle into its finest spray atmosphere and washing the pests from your plants. Do this early in the morning, once the water is still cold and the insects are lethargic. Direct the spray in the undersides of their leaves, where the pests normally feed, and then continue till the plants are dripping. For the best results, repeat the treatment on three consecutive mornings. If that’s impossible, aim for every other morning.
Organic Pyrethrum Spray
Organic, ready-to-use pyrethrum spray contains pyrethrins extracted from dried Dalmatian chrysanthemum (Chrysanthemum cinerariaefolium) blossoms. Use this organic insecticide to eliminate heavy thrips infestations. Spray a calm early morning or late night when no bees are foraging and the fever is between 50 and 75 degrees Fahrenheit. Dress in protective clothing, including a long-sleeved shirt, long pants, closed-toed shoes, safety goggles and a hat, and coat your crops till they drip. Because pyrethrum loses its effectiveness within one day, two follow-up software spaced three weeks to kill newly hatched larvae and any survivors are wise.
Lacewings and Pirate Bugs
Enlist support from green lacewings and minute pirate bugs, two notable thrips predators. Should you employ this tactic, however, keep in mind that pyrethrum eliminates the predators as well as the pests. Attract the beneficial insects into your garden by planting shallow-flowered, pollen- and nectar-producing plants such as variegated bishop’s weed (Aegopodium podagraria “Variegatum”) or sweet alyssum (Lobularia maritima), perennial in U.S. Department of Agriculture plant hardiness zones 4 through 9 and 5 through 9, respectively. Periodically rinsing dust from your plants additionally makes your lawn more inviting for all these beneficial bugs.
Spinosad Spray
Organic spinosad spray — a bacteria-based insecticide — contains neurotoxins that disrupt thrips’ nervous systems. As soon as they ingest it, then the insects stop eating and generally die within two days. To protect honeybees, apply spinosad just to plants which are not in bloom. Dress in protective clothing and mix 4 ins, or the manufacturer’s recommended number, of the spinosad concentrate in 1 gallon of water. Pour the mix into a hand-held, backpack or hose-end sprayer, and treat your crops at the early morning or at night, when no honeybees are energetic. Repeat weekly for up to five more weeks prior to the thrips are gone. Always follow the label’s instructions when working with any insecticide.