Most garden spiders eat common garden bugs such as bees, flies, cockroaches, mosquitoes, crickets, other spiders, beetles, butterflies and other small bugs. Spiders will usually eat anything that gets caught in their web.
Garden spiders are extremely beneficial in controlling pest populations in gardens. They frequently eat flies, gnats, aphids, mites, and any other little nuisance to your plants. Resist the urge to relocate or kill them--their benefits outweigh the creepiness of seeing them.
garden spiders eats the leaves of our plant.it will affect the growth of our plants.to avoid this there are some measures like anti-garden spider liquid.we can use these like liquids to protect our plants from garden spiders.