I’ve noticed tiny holes all over my baby lettuce and spinach. I’ve also seen small black bugs in my raised garden bed. Is there anything I can do to save my homegrown food?
— Finn, Silverthorne
This year, Summit County experienced an infestation of flea beetles that wreaked havoc on leafy vegetable seedlings. These small, shiny beetles chewed holes in the leaves of young spinach, radishes, broccoli and salad greens. The damage may have stunted growth and made our chard look like Swiss cheese, but it’s nothing a healthy garden can’t recover from.
At the same time, we already have a short growing season, cool nights and mountain dryness to contend with. Do we really need to add to the challenges of growing food at 8,000 feet? So what can we do about garden pests like flea beetles, aphids and powdery mildew?
These bad bugs can definitely frustrate the enthusiastic gardener. Beyond healthy soil and plants, there are several homemade recipes that can fend off some of these pesky pests. The first step before control is prevention. You can often prevent pest issues like flea beetles by using barriers such as row covers to protect your plants early on. My favorite row cover is Reemay, which comes in a variety of densities, from frost cloth to shade.
Since we are already midway through our growing season, we’ll focus on natural insecticides and repellents. Even if you are just now developing your green thumb, these are easy non-toxic recipes that anyone can replicate.
Neem oil: Neem comes from the neem tree and acts like a repellent for flea beetles, aphids and mites and as a fungicide for powdery mildew. It does not harm the beneficial bugs, so the butterflies, bees and spiders are safe. The oil is mixed with water (follow directions on the bottle) and applied as a foliar spray. It should not be applied in direct sunlight or extreme heat. (It’s best applied in the evening.) Also, it must be reapplied often to be effective.
Garlic spray: Garlic is general purpose insecticide and fungicide, so it should be used with caution on outdoor plants because it can kill the beneficial insects as well as pests. To make your own brew, mix a teaspoon of crushed garlic (or garlic oil) with water and spray the plants. The recipe works on aphids, flea beetles and powdery mildew.
Diatomaceous earth: To control ant damage or other creatures with an exoskeleton, sprinkle diatomaceous earth (purchase “food grade” only) into your garden bed. It’s an off-white, chalky powder that is the fossilized remains of marine phytoplankton. It’s safe for children and dogs. It’s also known to work for aphids, slugs and flea beetles.
Soap and oil: Mix 1 cup vegetable or white mineral oil with 2 cups of water and 2 teaspoons of bleach-free dish soap. Spray infected plants in the early morning or evening to avoid burning the leave. Great for aphids!
Spinosad: A fermented byproduct of actinomycetes (a good bacteria found in the soil), spinosad is very effective for many pests like flea beetles and aphids. Bugs must eat the spinosad for it to work, so it doesn’t harm the beneficial insects. However, do not use spinosad when flowers are in bloom because it may hurt honeybees.
If you’re looking for more tips and tricks for vegetable gardening, join us for “If Your Garden Could Talk” troubleshooting workshop on Thursday, July 11, from 5 to 7 p.m. at Colorado Mountain College in Breckenridge. Learn how to prevent disease, stunted growth and pest problems. Find out about mid-summer garden issues, soil needs, feeding, thinning, harvesting and other challenges. Bring your garden blunders and enigmas and have garden experts determine healthy solutions. The cost of the class is $25. To register, please contact CMC by calling (970) 468-5989.
Stand strong backyard gardeners! Take pride in knowing that if you can garden here, you can garden anywhere.
Ask Eartha Steward is written by the staff at the High Country Conservation Center, a nonprofit organization dedicated to waste reduction and resource conservation. Submit questions to Eartha at firstname.lastname@example.org.