ON THE GARDEN PATH by Carolyn Herriot

It is sad to think how often gardeners overlook the crucial role of wildlife in their gardens, when countless hours of toil could be saved. The key to attracting and keeping beneficials around is simply to grow a diversity of plants, with a focus on scent, and to provide the essentials of water, habitat and food.

Ponds or birdbaths provide water; you can also simply place shallow dishes around the garden. Water attracts frogs, salamanders and dragonflies and provides an oasis for thirsty insects and birds in hot summers.

The Lorquin’s Admiral and the Anise Swallowtail are the most prevalent species of butterfly in my garden. Swallowtails lay their eggs on fennel and dill, which are host plants for larval food. The Lorquin’s Admiral needs species of Salix (willow), Populus (cottonwood, poplars), Prunus (cherries), Spiraea (spirea) or Pyrus (apple) to complete its life cycle.

One of the best natural predators for aphids is our native ladybug (Hippodamia convergens). Ladybugs eat aphids in both their adult and larval stage; adults consume up to 5,000 aphids during their lifetime. It is important to recognize the larval stage of the ladybug so it is not mistaken for a pest. Larvae look like six-legged crocodiles, dark brown in colour with bright-orange spots on the back of their lumpy bodies. A mature larva can eat as many as 50 aphids a day, and between 200 to 500 aphids in its three-week lifespan. Ladybugs produce up to six generations a year, which accounts for a lot of aphids!

Dry-laid stone walls or log piles with turf incorporated can attract a wide range of fungi and insects as they biodegrade. These provide habitat for a range of creatures from snakes to mason bees and bumblebees, all of which like to nest in cavities. By simply piling up rocks, you can create a den for garter snakes, which I appreciate for being efficient slug predators.

Ornamental grasses provide excellent summer shelter and overwintering sites for slug-eating ground beetles, ladybugs and other beneficials. Seedheads of grasses provide useful winter insect habitat as well as dramatic winter interest in the garden.

Winter is the harshest season for birds; protection from cold and access to food become imperative for survival. Nesting boxes and evergreen trees and shrubs provide shelter for birds at this time. Feeders are helpful, as are plants that bear berries or hips. Cherries, crabapples, hawthorns, Amelanchier spp. (saskatoon or serviceberry), Ribes spp. (currants) and roses are all good food sources for birds in winter.

Gardening with wildlife has opened my eyes to new ways of enhancing the health of my garden. Broad-spectrum insecticides can be fatal to wildlife, but encouraging healthy populations of beneficials in the garden makes it unnecessary to use such products.

Plants that lure beneficials:

Achillea filipendulina (Fernleaf Yarrow) attracts lacewings and ladybugs. Agastache foeniculum (Anise Hyssop) has nectar-rich flowers that are very attractive to both butterflies and pest-eating beneficial insects. Anthemis tinctoria (Golden Marguerite) produces bright-yellow daisies, which are very attractive to five key kinds of beneficials: ladybugs, lacewings, flower flies, tachinid flies and mini-wasps. Borago officinalis (Borage) has bright-blue clusters of edible, cucumber-flavoured flowers. Common green lacewings have a strong preference for laying their eggs on Borage. Centaurea cyanus (Cornflower or Bachelor’s button) has nectar highly attractive to ladybugs, lacewings and beneficial wasps. Foeniculum vulgare (fennel) has flowers extremely attractive to nectar-feeding beneficial insects such as parasitic wasps, lacewings and hoverflies. Lobularia maritima (Sweet Alyssum) is highly attractive to syrphid flies, whose larvae eat dozens of aphids daily. Phacelia tanacetifolia (bee friend) has lovely purple-blue flowers irresistible to hoverflies and bees. Salix spp. Pussy willows are especially valuable because they produce pollen early in spring, when many beneficials are just emerging.

References
Garden Insects of North America by Whitney Cranshaw; The Organic Gardener’s Handbook of Natural Insect and Disease Control, edited by Barbara W. Ellis and Fern Marshall Bradley; Attracting Backyard Wildlife by Bill Merilees.

From A Year on the Garden Path: A 52-Week Organic Gardening Guide by Carolyn Herriot. Second edition $24.95. Available from your favourite bookstore or order online at www.earthfuture.com/gardenpath

Carolyn Herriot is author of A Year on the Garden Path, which talks you through growing food year-round and seed saving. Check out the weekly progress of The New Victory Garden in Victoria by following Carolyn's blog on www.gardenwise.ca