Spiders are nature’s insecticide.
October 28, 2024 - With Halloween coming up, I thought it would be a good time for some spider talk. I have always been a spider fan and certainly tossed my fair share of helpless insects into Argiope garden spider webs as a child.
Spiders are one of the garden’s most effective allies in controlling pests. Many common garden insects, such as aphids, caterpillars, beetles, mosquitoes, and flies, make up the majority of a spider's diet. Without spiders and other beneficial predators, many of these pests would thrive unchecked, damaging plants and crops. By naturally reducing pest populations, spiders help gardeners minimize the need for chemical pesticides, supporting a healthier, more balanced garden environment.
Different types of spiders specialize in catching different prey. Orb-weaver spiders, for example, build large, circular webs between plants to trap flying insects like flies, moths, and mosquitoes. Other spiders, like wolf spiders and jumping spiders, are active hunters that patrol the garden floor, pouncing on insects hidden in leaves and mulch. These hunters are quick and stealthy, often capturing pests that are too small to be noticed by gardeners.
While it is natural to feel uneasy around spiders, most garden spiders are harmless to humans. They are generally shy creatures that prefer to avoid contact with people. Spiders are far more interested in catching pests than bothering gardeners. In fact, if you encounter a web in your garden, it is best to leave it undisturbed—the spider is hard at work protecting your plants.
Creating a garden environment that welcomes spiders can enhance natural pest control. To attract spiders, avoid using broad-spectrum insecticides, which not only kill pests but also harm beneficial creatures like spiders. Leaving some leaf litter, mulch, or stones around the garden provides habitat for ground-dwelling spiders, while dense plants or shrubs give web-builders a place to set up shop.
Spiders are especially active in the fall as they prepare to lay eggs for the next generation. Just in time for Halloween, orb-weavers and other web-spinning spiders become more visible, their webs shimmering in the morning dew. While some gardeners may be tempted to clear away webs, leaving them intact can allow the spiders to continue catching pests during the final months of the growing season.
Spiders are an essential part of a healthy garden ecosystem, helping to maintain a natural balance between plants and pests. Their presence is a sign that your garden is thriving, full of biodiversity and life. By welcoming spiders into the garden, you can enjoy the benefits of natural pest control while reducing your reliance on chemical treatments.
Other than in the movies, I have never seen a human stuck in a spider web waiting to be devoured and I am quite sure that I never will. Remember, spiders eat insects and nothing else.
Greg Grant is the Smith County horticulturist and Master Gardener coordinator for the Texas A&M AgriLife Extension Service. He is the author of Texas Fruit and Vegetable Gardening, Texas Home Landscaping, Heirloom Gardening in the South, and The Rose Rustlers. You can read his “Greg’s Ramblings” blog at arborgate.com, read his “In Greg’s Garden” in each issue of Texas Gardener magazine (texasgardener.com), or follow him on Facebook at “Greg Grant Gardens.” More science-based lawn and gardening information from the Texas A&M AgriLife Extension Service can be found at aggieturf.tamu.edu and aggie-horticulture.tamu.edu.