Reprinted with permission from the Permaculture International Journal” (PIJ) #61 Dec – Feb 1997 page 17
Butterflies inhabit the earth for weeks at the most. Their existence is fragile but enormously important to the earth, from which many of their species are disappearing. Claire Hagen Dole enters their world to explain how we can create butterfly havens that enrich the planet and bring beauty to our gardens.
Photography: Craig Mackintosh
Have you ever noticed a colourful swallowtail butterfly gliding through the boughs of your apple tree? Have you watched a Painted Lady sipping nectar from a blackberry blossom. Like the industrious honeybee, these enchanting creatures are also pollinating blossoms as they move from plant to plant.
Throughout history, butterflies have been a subject of fascination; in some cultures, they’ve been equated with the human soul. Indeed, except for a few over wintering species, most adult butterflies inhabit the earth for a mere few days or weeks. Invite them into your garden; focus your gaze on their incredible journey from egg to larva to chrysalis (pupa) to winged adult. These life stages are so different that early naturalists thought they represented different animals.
The Very Hungry Caterpillar
Consider the second stage, the larva or the caterpillar. Who hasn’t plucked a caterpillar that is voraciously feeding on a desired plant? Some butterflies (like the widespread European Cabbage White) do cause damage to monoculture crops, but many caterpillars feed on weeds like nestles, thistles, or mallows. The spectacular Monarch (Danaus plexippus), which migrates from Canada to Mexico and ranges as far afield as Europe and Hawaii, lays its eggs on milkweed (Asclepias spp.). In addition, only one in ten insects found in the order Lepidoptera are butterflies; the rest are moths.
Should you find a bunch of caterpillars devouring a garden plant, try to identify them in a guidebook. Look in the host plant index and, if possible, for characteristics of the caterpillar: smooth, hairy, branched spines, etc. (Warning: larvae go through four or five stages which can look very different from each other and from guidebook illustrations.) An agricultural extension agent or entomologist may be able to help you.
Is there a benefit to leaving caterpillars to their feast? Insects form a large part of the food chain; only a small percentage of hatching larvae will survive to adulthood. You will see more birds in your garden when it’s populated by a diverse crew of crawling, bark-boring, and leaf-eating bugs.
Arguably, even the leaf-eaters can benefit both plant and soil by pruning heavy growth and dropping nutrient-rich frass (excrement) on the ground. Considering that larvae may bulk up to a thousand times their weight before pupating, that’s a lot of frass!
Of course it’s also a lot of leaves. How does a plant respond to this kind of stress? Some gardeners swear that letting a caterpillar devour leaves forces the plant to put its energy onto producing fruit. Plants can also emit chemicals that attract parasitic wasps; they may even be able to arrest their own development to wait out an insect’s life cycle.
Certain butterflies are widespread because they’ll lay their eggs on a vast number of plants. The painted lady (Vanessa cardui) is named after the thistle genus Carduus because it uses the spiny weed as a larval host plant. However, more than a hundred other plants, including borage and sunflower, will also fit the bill. Organic artichoke growers sometimes plant thistles among their rows to lure the painted lady to its favourite plant. Because it’s so common and nonspecific in both nectar and host plant choice, it’s the butterfly sold in caterpillar rearing kits.
The related Red Admiral (Vanessa atalanta) is another “weedy generalist who chooses fewer host plants, but ones that are widespread and opportunistic. In the mining spoils of Wales, barren soil supports two hardy plants that meet the Red Admirals needs – nettles (Urtica dioica) for its larvae, and butterfly bush (Buddleia spp.), a native of China that is named for its attractive nectar.
Most butterflies have narrower habitat and feeding requirements, making them vulnerable to development pressures and loss of host plants. Great Britain’s picturesque hedgerows, meadows and copses have sheltered butterflies and other wildlife for centuries, while preserving plant diversity. As they’ve been bulldozed for agribusiness, with its heavy pesticide use, butterfly populations have plummeted. Five species have become extinct and half the remaining 55 have reached dangerously low numbers, prompting a new project called Action for Butterflies.
Your Part in Saving the Butterfly
How can such damage be reversed? For many species on the verge of extinction, it probably can’t. But simple actions can aid local butterflies, as well as the many other creatures who inhabit your region. Think of your garden as a link in a wildlife corridor, part of the diverse canopy of grasses, flowers, shrubs and trees (both deciduous and evergreen) that feed and shelter them.
Enlist other members of the community to reduce lawns, stop pesticide use and choose a variety of plants that produce first nectar and then seeds. Think of native plants first, because they’ve evolved with local insect and bird species. Devote one corner of your lot, next to your neighbour’s corner, to providing the habitat that wild creatures need.
Butterflies are so sensitive to chemicals that scientists view them as indicator species for pesticide overuse. Hand pick pests when possible; even B.T. (Bacillus thuringiensis var. kurstaki), considered a safe organic pesticide, kills butterfly larvae along with targeted species like the Gypsy moth.
The Butterfly Garden
What special considerations will make your garden a haven for butterflies? You needn’t redesign the yard; start by incorporating a few nectar and host plants into your food garden.
Pick a sunny, sheltered spot. Large rocks or a stone wall make great basking spots for these cold-blooded insects. Block the wind with lattice or hedgerow. It’s a plus if you can put your butterfly garden near a kitchen or living room window for better viewing.
Fragrance and colour will draw in a passing butterfly; plant flora in masses for greatest effect. Access to the nectar is important – showy double blooms and hybrids don’t provide good perches or feeding sources. Some longer lived butterflies supplement their diet with decayed fruit, tree sap, animal scat, even carrion.
Butterflies frequent the edge between habitat zones, like the spot where a meadow meets the trees. The males, patrolling for a mate, can dart into the shrubbery for safety. Wood or brush poles also give shelter in bad weather or during winter months.
Provide a patch of wet sand or dirt for male butterflies, who gather to sip mineral-rich water – a behaviour called “puddling”.
Which plants bring in the butterflies? Try observing in your area, local guidebook in hand. Or plant Buddleia in a sunny spot, watch to see what butterflies show up and then plant their host plants, along with some bright nectar-producing flowers.
Butterfly pleasers include red valerian (Centranthus ruber) pin-cushion flower (Scabiosa spp.) Mexican sunflower (Tithonia rotundifolia), verbena, wallflower (Erysimum spp.) zinnia, marigold (Tageres spp.) orchid primrose (Primula vialii), cosmos, phlox, milkweed (Asclepias spp.) aster, coneflower (Echinacea spp.) yarrow (Achillea millefolium), and thistle (several genera including Cirsium and Cardus). Some exotic species of thistle are formidably invasive; make sure you choose a benign native variety.
Members of the family Umbelliferae, like fennel, dill and parsley, attract a variety of beneficial insects. Butterflies appreciate umbels, sturdy flower heads, where they can perch to sip nectar from one blossom after another. In North America, these plants are used as larval hosts by black and Anise Swallowtails. Plant enough to share with their attractive caterpillars, which are patterned in green, yellow and black stripes and spots.
A garden full of humming, buzzing, chirping wildlife, punctuated by the flutter of colourful butterflies’ wings, never gets boring. The more I learn about these amazing insects, the more I’m in awe of the complex web of life we all share. And I plant another marigold among the peas and tomatoes.