As summer brings warmer temperatures and some sunny afternoons, one of the most enjoyable sights in the garden is a variety of butterflies flitting from plant to plant, seeking nectar and egg-laying opportunities. Look for butterflies congregating in open, sunny spots with some wind protection.
To make garden areas more attractive to butterflies, plant some of their favorite nectaring flowers. Butterflies like flat-topped flowers formed from many tiny florets. Many flowers in the daisy family fit this profile. Daisies form a great landing platform for butterflies, and each daisy flower is formed from multiple tiny cone and ray flowers, each with its own miniscule nectar source. Butterflies can land in comfort and take advantage of many nectaring opportunities at once. Other examples include verbenas, buckwheats, lantanas, and yarrows, as well as plants in the parsley family. A well-planned butterfly garden will include a sequence of bloom, so that as one flush of flowers fade, it will be replaced by the next wave of blooms.
At the Garden for the Environment, the Water-wise Demonstration beds near the south gate provide a good demonstration of many butterfly plants. In fact, butterfly enthusiasts often drop by on a still, sunny day to spot many of our local butterflies feeding here. In these beds you can see three different yarrows, (Paprika, Moonshine, and our native millefolium) blooming along with Astericus maritima and Erigeron glaucus from the daisy family. Look also for Verbena rigida and Verbena bonariensis. Later in the summer, milkweed, Lobelia laxiflora, lantanas, and Eriogonum giganteum, (our native buckwheat “St. Catherine’s Lace”), will replace these flowers with fall-blooming butterfly snacks.
In addition to the flowers which provide food, butterflies need water. But they can’t drink out of deep standing water, such as a bird bath. Butterflies can be seen clustering where puddles form in damp sand or gravel. They can insert their straw-like mouth parts into the wet sand and suck up water along with dissolved minerals from the mud and sand. Butterfly fans call this behavior “puddling.” Butterflies will be attracted to puddles in sunny, wind-protected spots. You can even create a puddle for butterflies by putting a layer of sand or gravel with a little soil in a shallow dish with some water. Choose a sunny, flowery spot in the garden for your “puddle.”
At the GFE, butterflies, along with other beneficial insects such as honeybees, can be seen puddling near our grey-water demonstration area. In the heart of the garden, opposite our small greenhouse, our kitchen sink drains right into the soil above the exterior border. Here in a rock and gravel basin, water drains from the sink after hands or vegetables are washed, or watering cans are filled. These frequent small gushes of water support a planting of creek monkey flower and our California native columbine, as well as providing a puddling opportunity for our honeybees and visiting butterflies.
If you provide the right flowers and puddling opportunities, and attract butterflies to your garden, then naturally they will lay eggs and your garden will soon have caterpillars. Some caterpillars, like the cabbage looper, are destructive to food crop plants. But most caterpillars don’t do significant harm to garden plants, although they do feed on some leaves. Caterpillars are just baby butterflies, and we can’t have one without the other. Don’t kill caterpillars unless you can definitely identify them as a crop pest. Avoid the use of the pesticide “Bt.” Although Bt is a less-toxic (to humans) pesticide, it is fatal to all caterpillars, not just pesty ones. Bt is suspected as a factor in the decreasing number of monarchs.
A few chewed leaves is a small price to pay for the pleasure of seeing these colorful floating beauties flitting through the garden.