Not all spiders are bad. Just like Charlotte saved Wilbur, several harmless spiders can save your garden from insect pests. Instead of swatting away the spider webs outside, learn why spiders are good for your garden.
But watch out! Some spiders can be dangerous – although the ones you have to worry about usually won’t take up residence in your garden. Along with explaining the benefits of garden spiders, we’ll highlight a few friendly and not-so-friendly species of spiders to help you identify them.
3 Benefits of Spiders in Your Garden
Many spiders are practically harmless to humans but deadly to the insects that torment you and your plants. These are the best things about spiders gobbling up all the other bugs in your yard:
1. Get Rid of Pests
Do mosquitoes bite you every time you step outside? Are your prize flowers covered in aphids? Good news: Spiders eat both mosquitoes and aphids. In fact, spiders will eat pretty much any insect they can catch. That includes other common garden pests like beetles, flies, wasps, moths, leafhoppers, leafminers, caterpillars, and spider mites.
Whether the pest sucks the life out of your plants or tries to bite or sting you, spiders can get rid of it. The more of these voracious predators you let live in your garden, the fewer pests you’ll find.
Most spiders have perfect timing. They start hunting in early spring, right at the beginning of the growing season and the same time most pests become active.
2. Minimize Risk of Plant Diseases
If eating your plants wasn’t enough, pests can also spread the fungi and bacteria that cause plant diseases such as powdery mildew and black spot. Plus, when your plants are weak from pest attacks, they’re more vulnerable to those diseases.
So, when your eight-legged garden helpers reduce the number of pests in your garden, they also reduce the odds that your plants will become diseased.
3. Reduce Chemical Use in Your Garden
Spiders are the organic gardener’s best friend. By preventing pest infestations and plant diseases, they take the place of harmful insecticides and fungicides. That means spiders are especially good for fruit and vegetable gardens where you don’t want to spray chemicals.
2 Drawbacks of Spiders in Your Garden
No, we don’t count your arachnophobia as a reason to get rid of spiders in your garden. Even though they look creepy-crawly, most spiders are nothing to be afraid of. Even the ones with toxic venom prefer to hide away and keep to themselves rather than attack (the brown recluse spider is called that for a reason).
Still, there’s a price to pay for letting spiders hang around your garden. These are the drawbacks:
Danger to Pollinators
Remember when we said spiders will eat anything they can catch? That includes pollinators and other beneficial insects such as bees, butterflies, and ladybugs. You may have to choose between a thriving pollinator population and your own personal army of pest-killing spiders.
Unless you’re the kind of person who likes year-round Halloween decorations, you’re probably not crazy about the idea of spider webs covering your plants or your lawn. In addition to making your yard look messy (or haunted), those webs can actually block your plants’ and grass’s access to sunlight if they get too thick.
The good news is that not all spiders spin webs. Hunting spiders – explained in depth in the next section – offer pest control with no silk strings attached.
3. Most Common Types of Spiders in Lawns and Gardens
There are around 3,000 species of spiders living in North America, and any one of them could conceivably find its way into your lawn or garden. But you’re more likely to encounter some types of spiders than others.
These are some of the most common spiders found in lawns and gardens, split into three categories based on how they catch their prey.
1. Orb-Weaver Spiders
Orb-weavers are the spiders you’re probably most familiar with. They weave the classic spiraled, circular webs you see most often. These spiders lie in wait until the sticky strings of their webs catch insects for them.
You can expect to find these species of orb-weavers helping out in the garden:
- Garden spiders: Scientific name Argiope aurantia; yellow and black spiders that grow up to about 1 inch long; found throughout North America; bite is harmless to humans.
- Banana spiders: Scientific name Nephila clavipes; yellow, black, orange, brown, and white spiders that grow up to 3 inches long; found in the southeast U.S.; bite is harmless to humans.
- Joro spiders: Scientific name Trichonephila clavata; yellow and silvery-gray spiders with red markings on their underside that grow up to 8 inches wide; new invasive species currently found in the southeast U.S. but expected to spread up the East Coast and possibly across the whole country; bite is harmless to humans.
2. Funnel-Weaver Spiders
Funnel-weaver spiders still spin webs, but they operate a little differently. Their webs form a kind of mat along the ground, a tree, or a bush. One end of the web (the “funnel”) is a retreat where the spider hides from unsuspecting prey. Their webs aren’t sticky, but to make up for it, funnel-weavers are very fast. As soon as an insect wanders into their web, they pounce.
Grass spiders (scientific name Agelenopsis spp.) are the most common funnel-weavers. They’re light brown with darker brown stripes, and they grow up to about 1 inch long. You can find grass spiders throughout North America. As their name suggests, they often live in tall grass, but they can also make themselves at home in trees or bushes. Grass spiders’ bites are harmless to humans.
3. Hunting Spiders
Hunting spiders are the best at pest control because they don’t sit around waiting for prey to come to them. They travel through your grass and plants – anywhere they can find sufficient cover – and “hunt” down all kinds of insects. Since they’re always on the move, hunting spiders don’t weave webs that blemish your landscape.
These are some of the most common hunting spiders found in lawns and gardens:
- Wolf spiders: Members of the Lycosidae family; brown spiders with paler markings along their backs (colors vary by species) that grow up to 2 inches long; found throughout the U.S.; bites may be painful because of wolf spiders’ large mandibles, but the venom is harmless to humans.
- Crab spiders: Members of the Thomisidae family; spiders of varying colors with wide, flat, crablike bodies that grow up to ½-inch long and walk sideways and backward like a crab; found throughout North America; most crab spiders are too small to pierce human skin, but even the larger ones have venom that is harmless to humans.
- Jumping spiders: Members of the Salticidae family; appearance varies by species but often features bright colors and striking patterns and ranges from about 1/10-inch to just under 1 inch long; found throughout the U.S.; bite is harmless to humans.
Dangerous Spiders to Watch Out For
Spiders are just as scared of you as you are of them, and even the dangerous ones would prefer to avoid you. But if you step a little too close or brush up against their hiding place, spiders can feel threatened and attack.
So, if you suspect the spiders in your garden (or home) are the kind with toxic venom, it might be best to try and exterminate them, especially if you have kids or pets that tend to get into trouble. The pest control benefits aren’t worth risking your family’s health and safety.
Watch out for these spiders whose bites can potentially cause serious damage:
- Brown recluse: Scientific name Loxosceles reclusa; brown spiders with a violin-shaped marking along the back that grow up to just under 1-inch long; found from Texas to Florida in the South and from Nebraska to Ohio in the North; bite may cause fever, muscle pain, convulsions, nausea, itching, or, in rare cases, open skin lesions.
- Black widows/brown widows: Scientific name Latrodectus spp.; brown or shiny black spiders that grow up to ½-inch long with various red or red and white markings on the back or underside; different species found throughout the U.S., bite may cause severe muscle pain, cramps, spasms, extreme sweating, or increased heart rate that can last anywhere from a few days to several weeks.
- Yellow sac spiders: Scientific name Clubionidae mildei or Clubionidae inclusum; light yellow or pale beige spiders that grow up to about ¼-inch long with a dark, lance-shaped marking along the back; found in the eastern U.S.; bite may cause intense burning, rash, blistering, fever, muscle cramps, or nausea (although symptoms are usually less severe than black widow or brown recluse bites).
Despite common misconceptions, severe illness from spider bites, even brown recluse or black widow spiders, is rare. Extreme symptoms are most common in small children or elderly people. Symptoms may also be bad if you have an allergic reaction to the bite. Spider bites almost never result in death.
Another common misconception says that the hobo spider, common in the Pacific Northwest, is dangerous. But hobo spiders are no longer considered dangerous or toxic to humans.
How to Attract Spiders to Your Lawn and Garden
The best way to attract spiders is to give them lots of places to take shelter and build their webs. Insects in your yard already provide an ample food supply.
Some ways to provide shelter for spiders:
- Fill your garden with thick trees, bushes, and flowers where spiders can remain hidden.
- Leave grass clippings on the lawn and add mulch to garden beds to provide cover for ground hunting spiders such as wolf spiders.
- Don’t cut your plants back in winter so the spiders have shelter to overwinter in.
- Install permanent garden structures such as arbors, trellises, light posts, fencing, or statues.
- Try no-till gardening so you don’t disturb the spiders’ hunting grounds.
Whether you want to believe it or not, you’re never too far away from a spider. It’s pretty much guaranteed that there are already some living in your yard. But providing shelter makes your yard more hospitable and encourages your friendly neighborhood pest-killers to stick around and multiply.
FAQ About Garden Spiders
Garden spiders – the yellow and black ones most commonly found in gardens – usually leave humans alone but may bite if you run into their web or otherwise provoke them. Even if they do, the bite won’t cause any more harm than a bee sting (unless you have an allergic reaction).
Clean the bite with soap and water as you would any small wound. If it stings, itches, or swells, you can reduce these effects by applying a cold compress and elevating the affected area. Over-the-counter pain relievers (such as Tylenol) or antihistamines (such as Benadryl) can also help.
If the bite looks infected, or you develop more severe symptoms, seek help from a medical professional.
The effects of spider bites on cats and dogs are similar to their effects on humans. Potential symptoms include redness, swelling, muscle pain or cramping, tremors, vomiting, diarrhea, blistering, or pain in the abdomen.
Dogs and cats rarely die from spider bites, but animals with compromised immune systems may suffer kidney damage. Vets also say that if your pet eats a spider, it’s unlikely to cause any lasting issues. Still, if a spider bites your pet or your pet takes a bite out of a spider, monitor them closely for a few days and call the vet at the first sign of severe symptoms.
Yes, spiders are vital members of their local ecosystems because they help control insect populations. That’s not just good for your plants – it’s also a necessary part of the circle of life.
J. Jonah Jameson thinks Spider-Man is a menace even though he keeps the bad guys at bay. In case you’re of the same mind about actual arachnids, here are some steps to get rid of spiders if you find it absolutely necessary to do so:
— Control insects in other ways so spiders have nothing to eat. Use pesticides or eco-friendly integrated pest management strategies to reduce pest populations in your yard.
— Use spider repellents, which include scents such as peppermint, lemon, citronella, and rosemary.
— Keep plants neat and trim so spiders have fewer places to hide.
— Clean up litter such as fallen leaves, grass clippings, or mulch that may provide cover for spiders.
Keep in mind, it’s almost impossible to get rid of all the spiders in your yard. But just like our tips for attracting spiders make your yard more hospitable for them, these tips make your yard less appealing so it’s less likely to attract eight-legged menaces.
Other Beneficial Bugs
Spiders aren’t the only creepy crawlies that are good for your garden. Many other bugs are beneficial, including:
- Pollinators such as bees and butterflies help with the production of fruits and veggies.
- Predators such as ladybugs, praying mantises, and assassin bugs (along with spiders) feed on pests that would plague your lawn and garden.
- Parasites such as parasitic wasps kill common lawn and garden pests by laying their eggs inside the larvae before they can grow into full-blown pests.
- Decomposers such as earthworms and pill bugs break down decaying plant and animal matter to add nutrients to the soil and boost healthy plant growth.
These helpful bugs and others like them are why you should avoid pesticides at all costs. Most pesticides are indiscriminate, killing the good bugs with the bad. In the long run, this harms your lawn and garden more than getting rid of pests helps them.
When spiders aren’t enough to control your lawn and garden pests, call a pest control professional for help.
Main Photo Credit: dirtdiver38 / Pixabay