Spiders are predators, and their presence in the garden is a response to two fundamental needs: a reliable food source and suitable shelter for web-building or ambush hunting. Plants do not contain a chemical signature that spiders seek out. Instead, they create a beneficial micro-environment that these arachnids readily exploit by providing cover and concentrating prey.
Understanding the Attraction Mechanism
Spiders are drawn to plants indirectly because plants act as hosts for their insect prey. The primary motivation for a spider to inhabit a specific plant is the population of small arthropods it supports, not the plant’s leaves or flowers. If a plant harbors a large number of aphids, gnats, or flies, it becomes a profitable hunting ground. This explains why spiders are found on both healthy and stressed plants. A healthy, flowering plant attracts pollinators that web-building spiders capture, while a stressed plant may be infested with pests like whiteflies, which are food for hunting spiders.
Plants That Attract Spider Prey
Plants that concentrate insect prey often have dense foliage, high nectar production, or specific chemical cues that insects find appealing. Heavily flowering annuals and perennials, such as sunflowers and chamomile, are prime candidates. They attract large numbers of flying insects, including bees and flies, which orb-weaving spiders target. Sunflowers offer tall, stable stalks that provide ideal anchor points for large webs designed to catch flying prey. Plants suffering from common pest issues also inadvertently attract spiders, such as citrus trees and tomato plants struggling with high populations of aphids and whiteflies. Furthermore, plants with sticky exudates, like glandular trichomes, can trap small insects, providing an inexpensive food source that draws specific spiders, such as those from the Peucetia genus.
Structural Features Spiders Seek for Shelter
The physical structure of a plant determines its desirability as a spider habitat, independent of food availability. Spiders require stability and secure attachment points for web construction, favoring tall, unyielding structures. Plants like corn stalks, foxglove, and pole beans offer straight, strong stems that resist wind movement, making them perfect foundations for webs. For spiders that do not build webs, such as wolf spiders or crab spiders, the structure must provide ample cover for ambush or shelter. Dense vegetation that creates shade and humidity, like thick shrubs or ground cover, offers a perfect hideaway. Plants with layered leaves, deep crevices, or rosette-shaped growth, such as bromeliads, provide protected microhabitats against predators and weather.
Plants That Can Help Deter Spiders
Some plants are cited for their potential to discourage spider presence due to the strong volatile organic compounds they release. These plants belong to the mint family (Lamiaceae), including peppermint, lavender, and basil. The theory suggests that the pungent, aromatic oils, such as linalool in lavender and menthol in peppermint, may interfere with a spider’s chemoreceptors or mask the scent of prey. Scientific testing has shown that certain substances, including peppermint oil and volatiles from chestnuts, can strongly repel some spider species, such as the Latrodectus geometricus. Conversely, other cited repellents, like lemon oil, have been found to have no significant effect. Planting aromatic varieties near entry points or windows is a popular, low-impact strategy to create an undesirable environment for many common garden spiders.