Many people love butterflies and want them in their garden. But if you ask, "do you want caterpillars chewing on your garden plants?" you may get a different answer.  The truth is, butterflies (and all moths -- butterflies are day-flying moths) have different food requirements as they develop through the stages of egg, caterpillar, pupa and adult. Most caterpillars are specialized feeders on fresh green leaves, and feed on only the leaves of a few native plant species they coevolved with. If we want our native butterflies to thrive, such as the beautiful Monarch butterfly pictured, we must include the food plants of their caterpillars in our gardens. In the case of Monarchs, the food plants for the caterpillars are various species of native milkweeds, e.g., common milkweed, Asclepias syriaca, or butterfly milkweed, Asclepias tuberosa. Once the caterpillars grow up and metamorphose into adult butterflies, they become pollinators and drink nectar from many different kinds of flowers, native and non-native. But only native plants provide food for the larval, or caterpillar stage. Plant native plants and start your biodiversity garden today! The photos for this post were taken in our Biodiversity Garden in London, Ontario, in mid-August 2022.

I had a fantastic experience being interviewed by Dr. Tony Weis, geography professor at Western University, for a project of the Rachel Carson Center. Read the article here: Overcoming the Fear Factor: Teaching and Learning about Insects and Biodiversity.

Need a little inspiration to start your native plant garden this spring? This coming Thursday evening, May 2nd, at 7:00 pm I will be speaking on biodiversity gardening at the  Wolf Performance Hall, London Public Library, in downtown London, Ontario.  This event is free and open to the public. 2 hours free validated parking in City Plaza during Library hours. See you there! (photo: Bloodroot, "Sanguinaria canadensis" taken several days ago in our biodiversity garden in London).

I took the photographs above on 14 June, and posted the top one on Twitter shortly after.  I observed the male red-bellied woodpecker drumming just before I took the photo (top).  There were multiple snags.  The pair of flickers (below) were engaged in courtship. Yes, these are common species, but they are beautiful nonetheless.  They have value. 

About a week later I discovered that the snags had been cut down and removed.  It is possible they were determined to be a hazard to people, but I doubt it, given the location and the project going on. Even if they were deemed a hazard, could the design have been altered to keep the people and the other species' homes safe?

If a tree must be cut down, don't remove it.  Leave it on the ground, if possible.  But please try to keep dead trees standing by designing people-spaces around them.  Let dead trees be.  They are home for other species.  ​

Many gardeners dutifully plant nectar sources for adult butterflies. But they may not be aware of the details of the life cycle of butterflies.  Most butterflies require native plants in order to reproduce. Butterflies start out in life as eggs, then hatch into caterpillars.  Most caterpillars are specialist feeders, and eat only a few species of native plants they coevolved with.  Butterflies will only lay their eggs on their native host plants; caterpillars will eat only these same host plants.  The typical North American garden full of alien plants such as periwinkle, hostas, Norway maple, etc., and even the so-called butterfly bush, will not feed our native caterpillars.  If you want butterflies, you've got to have caterpillars, and caterpillars require the fresh green leaves of native plants.  And, the flowers of native plants are excellent pollen and nectar sources for all pollinators.  Most of us are aware that the monarch butterfly requires native milkweeds for its caterpillar.  It is no exception.  If all gardens had host plants for caterpillars, butterflies might not be in decline.