White Flies
Are white flies out of control on your plants? Are you wondering where they came from? Do you need solutions?
This time of year, when it’s hot and dry, plants are stressed and more prone to attack by all kinds of insect pests.
White flies often hitch a ride to your garden on plants you buy. Always inspect plants before bringing them home! White fly eggs and larva can lurk in potting soil, too. It’s wise to quarantine new plants for a week to 10 days for that reason.
White flies, like many pests, home in on plants by smell. When plants are stressed, white flies find them more attractive. Healthy plants are more resistant to pests.
You may think you are promoting plant health by boosting fertilizer applications. But be cautious with nitrogen! An excess of nitrogen makes plants more attractive to white flies! Know your soil through testing and don’t fertilize blindly.
So how can you deal with white flies if they invade your garden?
Early in the season, reflective surfaces such as aluminum foil or Mylar sheets placed under plants confuses white flies reducing their ability to find your plants. Don’t use this approach in direct sun or hot weather!
Hosing plants with water will dislodge white flies and their nymphs. Follow this with a spray of soapy water. Don’t apply soapy water in hot weather.
Neem oil can also be used as long as temperatures don’t rise beyond the mid-90s.
White flies are attracted to yellow. You can purchase or make yellow sticky traps. A mixture of equal parts Vaseline and liquid laundry detergent spread on yellow cardstock or yellow plastic cups will attract white flies and they will be stuck in the mixture. A product called Tanglefoot is a very effective coating for traps.
A handheld vacuum can be effective in removing white flies and their eggs and nymphs. Just don’t let them escape when you empty it!
Encourage beneficial insects such as ladybugs, parasitic wasps, and dragonflies for white fly control. Avoid pesticides as white flies are highly resistant, but beneficial insects will be killed.
The best approach is vigilance. Take care to avoid bringing white flies into your garden, maintain plant health, and encourage beneficial insects.
Happy gardening!
