How to prevent pests from eating lettuce?
Written by
Benjamin Miller
Reviewed by
Prof. Martin Thorne, Ph.D.Growing lettuce pest-free involves being deliberate with multiple strategies. For example, I mix physical barriers and biological controls in my urban garden. The marigold borders repel nematodes while a garlic spray deters aphids and other pests. I make a habit of inspecting the leaves of lettuce weekly - it was that habitual inspection that led to catching an infestation of aphids early last season on my buttercrunch.
Physical Barriers
- Floating row covers block 90% of flying pests
- Copper tape repels slugs within 6" (15 cm)
- Diatomaceous earth dusting stops crawling insects
Biological Controls
- Ladybugs consume 50 aphids daily
- Nematodes target soil-dwelling larvae
- Companion plants emit pest-repelling compounds
The health of soil affects pest resistance. I use a combination of 40 % compost and 20% worm castings. It helps provide plants with immune strength. If you have not already done so, check your drainage - the water should absorb in 8 seconds. Slow drainage promotes a population of fungus gnats - simply adding perlite will help. Fast drainage? Add coconut coir for moisture retention.
The timely application of pesticide applications enhances effectiveness. Spray neem oil when beneficial insects are at rest at dusk. Apply diatomaceous earth after the dew has dried - it can lose its abrasive quality in the morning humidity. Reapply again after rainfall. I use a moon phase calendar to help me monitor the best times for treating pests, which results in a benefit of 25% ease of application.
The practice of companion planting provides living barriers to pests! I stagger every 18" (45 cm) row of lettuce with rows of garlic. The sulfur compounds repel aphids and also sweeten the taste of your soil. I plant radish seeds every 3' (90 cm), using them to lure leaf miners away from my delicate greens.
Read the full article: How to Grow Lettuce: Expert Tips for Every Gardener
