Growing Green, A Family Gardening Series: Week 6

In this week's blog: Managing Pests

By this time in the growing season, you have probably suffered some plant damage from pests. Let me start by saying: it’s pretty much unavoidable. You will never get rid of all pests – and if you did manage, you could be getting rid of another being’s food source! The goal with gardening, in my opinion, should be to manage pests for an acceptable loss (I don’t want to lose an entire crop, but I could handle the sacrifice of one-tenth) and to promote biodiversity to spread out risks and encourage beneficial species that will help ward off or fight pests. In order to do this, I also use safe pest controls when I use them at all (sparingly) – no chemicals that might negatively affect soil, water, or non-target insects.

There’s a certain amount of ickiness in dealing with (and googling) some pests, and this is a great chance to help your kids to learn to appreciate and value insects so they do not turn out like my teen, who will not dig in the garden for fear of uncovering earthworms. Too late for me! 

Work with your child’s natural curiosity and model the behaviour you’d like to see. Insects truly are fascinating, and they are also small, catchable, and easy to find.

This video for young children is a great example of how to encourage children’s interest and interaction with insects.

Minibeast Adventure with Jess- Bugs in the Garden (Video by Wizz)

They can hone their observation skills, and through that, learn to appreciate nature. They may even help in getting rid of pests. A penny per potato bug caught helped me overcome some of my squeamishness as a child!

The three basic pests in my garden, in increasing order of severity, are rodents, birds, and insects. You may find that these are more or less serious for you where you live. My sister in Quebec, for example, had serious groundhog damage before she put up a chicken-wire fence around her garden, but we don’t even have groundhogs where I live. The rabbits that come into our yard tend to prefer the clover I’ve planted for the bees and the dandelions I can’t get rid of, to any of my vegetables or flowers. And I have such a jungle of plants and shrubs that the ground squirrels that infest the schoolyard behind me don’t enter my yard: they like to be in a well-mowed place so they can see predators coming. However, I have had trouble with birds eating my beet and swiss chard leaves, complaints which I haven’t heard from other people. And everyone I talk to about gardening suffers from flea beetles.

There are a few main approaches to dealing with pests. The first is to prepare a garden that does not appeal as much to them (as mine doesn’t appeal to ground squirrels). You can try to choose varieties that are resistant to pests – for example, deer do not like to eat irises or most herbs. Healthier plants will also survive attacks of pests that prey on the weakest. You can also plant ‘companion plants’ that may repel pests. For example, marigolds are reputed to repel certain harmful insects. 

Another approach is to use physical barriers. I use bird netting to keep birds from my cherries and swiss chard. Small rocks painted red (this would be a fun craft for kids) placed in a strawberry patch helps deter birds from eating the strawberries after they get a beakful of rock instead. I have used plant collars made from aluminum cans (this video shows the method with other materials) to block cutworms from cabbages and tomatoes. The main barrier I use in my garden, and would never want to do without, is row covers. These are light fabrics that are permeable to sunlight and water that keep off flea beetles and cabbage butterflies, which are so rampant in our area because they feed on the dominant canola crops. I couldn’t grow healthy kale, cabbage, broccoli, or any other brassica without them. And as a bonus, they can also be used as frost covers when you are trying to save plants from a light frost.

This cherry was attacked before I put the bird netting on the tree.

A time-tested physical control is hand-picking, and here is where I admit to some squeamishness. Although there are some insects I’m happy to touch, I will only knock “gross” bugs like slugs, cutworms, or potato beetles into a paper bag with a stick! This is where I could really use a curious kid who revels in squishing bug eggs or collecting insects. It is also a good idea to pick off parts of plants affected by insects and destroy them – not only are they weak parts of the plant, but they may also have the insect or eggs still on them. This is my method of dealing with leaf miners, which actually burrow inside the leaf.

There are some fairly harmless insecticides such as BT and pyrethrin that target certain pests. In all use, follow the guidelines very carefully. Always spot treat rather than spraying a wide area, don’t spray between sunset and a few hours after dawn, and never spray while in bloom because that could affect pollinators.

Finally, I try to attract beneficial insects such as parasitic wasps that prey on damaging insect larvae. This is where having a range of flowering plant types and suitable living conditions helps – and the next blog post on pollination will go into detail on these!

Naomi Beingessner has lived and gardened in the Prairies for most of her life. She has two children, an enthusiastic gardener and an enthusiastic eater. She was a high school teacher and is now back in university studying food sovereignty. Her favourite vegetable is green beans but she finds that the most significant taste difference between store-bought and home-grown is in tomatoes.