July 12th, 2007
Yesterday, robin from Dharma Bums commented:
Someday, if you haven’t already done so, maybe you could tell us what you planted to attract all these incredible spiders into your spider garden. You do have such an inspiring diversity of species there.
Shortly after I began this blog, I wrote a post entitled Thirty Years Later that does explain how our land has changed over time. Sometime very soon – perhaps next week, I’ll post some photos taken at various locations around the property to give some idea of the habitat here. However, today, I thought it might be useful to write something about how one could go about creating biodiversity in a garden. This is just something short and more a starting point than a how-to-do-it treatise.
When I first began photographing insects, I didn’t pay a great deal of attention to the plants where each one was found. I believe I may have thought that it was just “luck” that I found a certain insect. It took at least a few weeks before I realized just how strong the connection was between plants and insects, and that I could make use of that connection when searching for a particular creature. Insects that are found around a particular plant are called “associates”. They may be attracted to it because they feed upon it, but they might just like to perch or hide on it, or perhaps it’s where their favourite prey hangs out. In any case, it really was an earth-shaking moment for me as I realized just how important it was for me to understand the connection between plants and insects.
As described in the Thirty Years Later post, we didn’t really do much in the way of plantings other than trying to plant a good variety of trees. Instead, we let the old fencerows around the farm grow wild, and didn’t do too much cutting of the pastures after we stopped growing hay and grain for our horses and a large herd of dairy goats (now long gone). When planting trees, we left many areas of pasture open as there are certain birds and insects that require the habitat of grasslands or oldfield pastures. In the gardens around the house, we have a mix of cultivated plants, and of native and non-native “wild plants”. Of the cultivated plants, they include mainly rugosa roses, day lilies, peonies, a variety of perennials such as phlox, delphiniums, and pink turtlehead, hostas, and bushes such as hydrangea, lilac, highbush cranberry, and elderberry. Of the wild plants (native and non-native), the most useful for attracting insects are Common Milkweed, Goldenrod, Queen Anne’s Lace, Daisies, Black-eyed Susans, Asters, Mullein, Virginia Creeper vines, Wild Cucumber, and a few different species of ferns. By far and away, Common Milkweed (Asclepias syriaca) is the best plant I can think of to attract an amazing variety of insects and spiders. I’m just now beginning to try to create a list of all of the creatures I commonly find on milkweed, but I can already tell you that it will be a very long list. As well, Common Milkweed is a critical plant for Monarch butterflies (Danaus plexippus), so that alone is enough reason to have some in your garden if you’re interested in wild plantings.
Returning to the idea of “plant associates”, I try to read up on certain insects that I would like to see, and then look on the plants where they are likely to be found. If I wanted to see a certain insect — say, a certain species of butterfly or moth — then I’d be sure to plant its larval food somewhere in the garden. For example, Black Swallowtail butterflies (Papilio polyxenes) larvae eat parsley, dill, carrot, and Queen Anne’s Lace, so I would be sure to plant those if I wanted to see the butterflies around my garden. As far as reference material goes, good insect field guides should provide information on food plants for each species. Those interested in Lepidoptera (butterflies and moths), should consult David Wagner’s Caterpillars of Eastern North America. He provides plenty of information on the food plants of almost all species covered in the book. Likewise, The Butterflies of Canada by Layberry, Hall and Lafontaine, describes both the habitat of each species, along with typical foods (see the “Early Stages” entry for each species). For those who are truly interested in learning about plant and insect relationships, there’s a very nice series of books written by John Eastman and illustrated by Amelia Hansen — these are simple field guides with ink drawings of plants, shrubs and trees. There’s an “associates” section for each plant. I’ve found the books quite helpful, particularly in the case of figuring out which larvae, eggs, galls, etc.. are found on a particular plant. Unfortunately, these books are intended for use in Eastern North America, but I’m guessing there are equivalents for other regions as well. A couple of their titles on my own shelf are The Book of Forest and Thicket and The Book of Swamp and Bog. I’ve been meaning to pick up a copy of The Book of Field and Roadside. I expect that last one might be very useful to someone attempting to create an oldfield type of garden. That’s pretty much what my own garden is — a sort of “oldfield meadow” which surrounds our house, and is bordered by conifers. Again, I’ll try to put together a post that is sort of a “grand tour” of our gardens very soon.