A wildflower section in Phil Thomsen's Whanganui garden. Photo / Phil Thomsen
A wildflower section in Phil Thomsen's Whanganui garden. Photo / Phil Thomsen
The role of insects in Whanganui gardens By Phil Thomsen
In an earlier Conservation Comment article, I discussed the topic of encouraging native birds in gardens. Some of these birds feed on insects. For instance, korimako (bellbird), waxeye and tui frequently forage for them. One can never tire of the delightsof watching the antics of piwakawaka (fantail) as they catch flying bugs. So is there benefit in encouraging insects too?
Flowers are one of the main ways to attract insects. People often assume that these insects are bees; however if you inspect them or watch their behaviours, many are in fact beneficial flies or wasps. The mere mention of these causes most people to reach for the bug spray. However, the vast majority of these wasps don't sting, and are often predatory or parasitic on pests. Some flies are the same – hover flies are so named because they hover stationary in the air. These flies are also predatory of pests, and are another pollinator of flowers.
In my garden, I have thyme, lavender and other herbs, which can sometimes be difficult to weed around in the middle of the day, being so popular with bees! One of my favourite herbs is borage, which flowers profusely and self-seeds readily, and is a member of the Echium family, a drawcard for many insects. Berries, for example raspberries, also have a long flowering period and again draw copious insect pollinators.
Another popular garden style is wildflower gardening. Packets of mixed seeds can be bought for this purpose. However, my approach is simply to find an attractive flower that grows and seeds well in my area, and spread the seed around. This way, I know I'm on to winners (see the picture). In my particular garden, the flowers I encourage this way include poppies, verbascum, purple linaria, and spur valerian. Plus the borage that I mentioned above. When they finish flowering I pull them up and spread the plants as mulch. More insects work to break them down, adding to the organic matter in the soil and providing further food for birds!
There are far more kinds of insects in the world than there are all other life forms combined and they have the ability to fill many habitats and evolve rapidly. However, it is sobering to find that the number of insects globally is declining, owing to human pressures. So it is great if we can make a small difference in our gardens.
Phil Thomsen is a life-long gardener and conservationist.
