Beneficial Insect: Spiders

Garden Spiders: Friend or Foe? (Spoiler: They're Friends)

Few people have neutral feelings about spiders. Some are repulsed by their spindly legs, numerous eyes, and venomous bites (though most are harmless to humans). Others are fascinated by their artistic web designs and their wide range of shapes, sizes, colors, and behaviors.

But even if you fall in the first camp, you should know that spiders are tremendously beneficial to gardens. Many of the bugs they capture and eat are pests that harm garden plants, including aphids, beetles, and caterpillars. For you, that’s free natural pest control.

Spiders also provide indirect support for pollination, mainly by preying on insects that damage plants. Healthier plants are more likely to produce vibrant flowers that attract pollinators like bees, butterflies, and birds. And because spiders help control pest populations naturally, they minimize the need to use chemical pesticides. That creates a safer environment for pollinators, which can be sensitive to chemicals.

So, if you spot spiders in your garden, consider yourself fortunate.

Understanding spiders

While there are more than 45,000 known species of spiders, some are bigger fans of garden settings than others. Some of the most common garden spiders include:

• Garden spiders (Argiope): These striking spiders often build large, conspicuous webs in sunny areas with lots of insect traffic. Many display striking colors and patterns, including the black and yellow garden spider and the banded garden spider with its bands of black, yellow, and white.
• Jumping spiders: They’re recognizable by their short, stocky build and talent for jumping long distances. Jumping spiders are active hunters that don’t rely on webs to catch their prey. Instead, they stalk insects on plants and soil.
• Wolf spiders: These ground-dwelling spiders are also active hunters that chase down their prey rather than catching it in webs. If you spot one, it probably will be running across the ground.

Not-So-Welcome Guests: Spiders to Watch Out For

While most spiders you'll encounter in your garden are harmless and beneficial, a few species warrant caution. It's important to be able to identify these spiders and take appropriate precautions if you encounter them.

• Black Widow: This notorious spider is easily recognizable by the red hourglass marking on its abdomen. Black widows prefer dark, secluded areas and are usually found in woodpiles, sheds, or under rocks. While their venom is potent, they are not aggressive and will only bite if disturbed.
• Brown Recluse: This spider is more challenging to identify because its brown coloration can blend in with its surroundings. Brown spiders are usually found in undisturbed areas like closets, attics, and woodpiles. Their bite can cause a necrotic lesion, so it's important to seek medical attention if bitten.
• Crab Spiders: These spiders are named for their crab-like appearance and sideways movement. While they don't spin webs, they ambush their prey, including beneficial insects like bees and butterflies. Their bite is typically mild for humans, but it's best to avoid handling them.

To manage these less-than-desirable spiders, keep your garden areas well-maintained and free of clutter where spiders might hide. Regularly check and clean out sheds, woodpiles, and other undisturbed areas. Wearing gloves and long sleeves while gardening can provide an extra layer of protection.

If you encounter a potentially dangerous spider like a black widow or brown recluse, it's best to contact a pest control professional for safe removal.

Because spiders do such a great job controlling garden pests, it’s still worthwhile to encourage beneficial spiders to visit your garden.

Attracting beneficial spiders 

How do you do that? Start by growing a diverse mix of plants including flowers, shrubs, and ground covers. That will provide habitats and attract a variety of insects that spiders can eat.

It’s also helpful to offer open areas where orb-weaving spiders and garden spiders can build their webs. Spaces between plants, trellises, and fences are ideal.

Keep in mind that spiders need water to survive. You can help by providing a shallow water source, like a small dish of water, to attract spiders and other beneficial insects.

One thing to avoid, or at least reduce, is the use of outdoor lights at night. Artificial lighting tends to deter spiders and attracts pests that can disrupt the spider's hunting activities, like moths or flies.