Beating the Bugs
by VCE Agent Kirsten Conrad
The information here was originally published in a monthly column on pest control in Between the Rows – A Guide to Vegetable Gardening published by VCE in collaboration with MGNV.
Don’t miss Kirsten’s in depth online class:
What’s Eating My [Cucumbers, Tomatoes, Eggplant, Beans, Squash]? :
Insect Pest Management for the Vegetable Garden
Pests of Cool Season Plants – Lettuce, Radish, Leafy Greens
In March, thoughts turn to delicious memories of early spring delicacies from the garden, and, truth to tell, these are some of the easiest, fastest, and most pest-resistant crops to grow. But there are challenges to growing radishes, lettuce, and other leafy greens as early spring crops.
Pest management starts with proper culture and stress avoidance right from planting. With radishes and leafy greens like spinach and kale, simply sow the seed directly on finely raked sandy loam garden soil and cover lightly to a depth of ½ inch. For lettuce, avoid covering the seeds, which need sunlight to germinate. For a spring crop, all of these early vegetables like full sun but will tolerate part shade. Soil testing in the fall allows you to have the preferred pH for your garden crops at about 6.5–7.0, and, like the rest of your garden crops, these spring plants appreciate a small amount of balanced fertilizer for healthy growth, plus a side dressing of compost as a nutrient source after 30 days.
Radishes and lettuce will mature in 30–50 days and chard, kale, and spinach in 40–70 days. Thinning is an essential task. Be sure to give radishes plenty of room by spacing them no closer than 1 inch apart in rows about 12 inches apart. Lettuce plants should be spaced 6–12 inches apart depending on the variety and will appreciate mulching to keep leaves off the soil. The spacing of chard, kale, and spinach depends on the size of the mature plant. As a general rule, space them far enough apart that the outermost leaves are touching when they are nearly ready to harvest—about 4–6 inches for spinach and mustard greens and 12–24 inches for kale and collards.
You may see problems from pests that like cool, moist conditions like slugs and snails, and you may also see overwintering harlequin bugs, flea beetles, aphids, leaf miners, and early cabbage looper larvae. Crop rotation is a great way to fool these insects, and, since all of these overwinter in the soil or on plants left in the garden in the fall, one of the best ways to prevent heavy infestations is to do fall garden cleanup and tilling. Floating row covers provide protection from insects, rabbits and deer, and late cold snaps. Consider interplanting with flowering herbs and annuals like tansy, marigold, chives, mint, thyme, nasturtium, and rosemary known to repel insects. Check out these publications for more information:
- Beneficial Insects in the Garden
- Home Grounds & Animals: 2022 Pest Management Guide – Vegetable Insect Section (see info beginning in section 2-1)
Your best bet is to keep your plants growing vigorously and attract beneficial predators that include lacewings, damsel bugs, parasitic wasps, birds, toads, spiders, ground beetles, and lady beetles.