The more closely you look at a healthy garden, the more likely you are to notice the plethora of insects and spiders that keep it in balance. Take a close-up picture of a flower, and when you look at the photo on a bigger screen, don’t be surprised if someone you hadn’t noticed is lurking.
A healthy garden needs beneficial insects and spiders to pollinate, control insects that damage plants and aid decomposition. Of the million species of insects, approximately 99% are beneficial or benign.
Spiders are especially beneficial in the garden. Crab spiders sit at the edge of a flower, often blending into the flower’s color, as they lay in wait for their next meal.
The spiders commonly found in California are not harmful to people, with one exception: a female black widow spider will bite if provoked, so be careful when rearranging wood piles or rummaging in dark corners of the garage or yard.
Creating the proper environment
Welcoming the tinier, less obvious beneficials to your garden is not that different from welcoming birds, butterflies and pollinators: They need food, shelter, places to raise their young and water. In addition, avoid using pesticides or bug zappers, which will also kill beneficials.
• Food. Although many beneficials are predators that consume insects that munch on your plants, they also eat nectar and pollen. Having a succession of native plants in bloom year-round encourages them to stick around. Tolerating a small colony of aphids early in the season can attract the predators that will keep them in check the rest of the year.
• Shelter. A variety of habitat levels in the landscape can encourage a diverse array of beneficials. Trees, shrubs, grasses, perennials and groundcovers all provide floral resources as well as different ecological niches.
Maintain a healthy layer of leaf litter for predaceous ground beetles. Leave bare patches of earth for ground-nesting bees.
• Places to raise their young. Learn to recognize the eggs and larvae of beneficials. Lady beetle eggs are yellow-orange clusters on the undersides of leaves, often seen where aphids are prevalent. Green lacewing eggs are laid on stalks so that the newly hatched larvae don’t immediately eat each other. The little white dots on some caterpillars are eggs laid by tiny parasitic wasps. On hatching, the larvae eat the host caterpillar from the inside out.
• Water. Small, shallow mud or water features enable beneficials to take a drink without drowning. Set up a shallow dish with plants and rocks, or a saucer with sticks and rocks. To prevent mosquitoes, flood the dish daily until it overflows.