Consider adding one more to your list of new year’s resolutions – reduce your use of lawn and garden pesticides. Most prairie gardeners are aware of their negative impact on our environment. The great majority of insecticides are broad-based rather than specific. They target the “good guys” as well as the pests, upsetting the natural balance of pest, predator and parasitoids that would normally exist in our landscapes. Many pesticides are also toxic to pets and people. They can enter our food web and our ground water. As well, insects and diseases have a remarkable capacity for adaptation and often develop resistance to these products, rendering them ineffective.
As gardeners, we want to create a pleasing outdoor environment. We’re also pressured by our neighbours and by the persuasive and pervasive marketing of the manufacturers of these products to have an immaculate lawn and garden.
One of your objectives in managing pests in your gardens should be to gain a satisfactory level of control with the least harm to the environment and the least risk to your family, neighbours and pets.
So how does one balance these competing goals? Begin by simply resolving to “reduce” their use for 2017, and as it works, take the concept further.
Here are some strategies:
1. Keep plants healthy
Like people, healthy plants are less vulnerable to disease. Give them the conditions in which they will flourish. Some prefer full sun, others shade. Some are drought tolerant, while others need an even moisture supply. Do your homework. This may be as simply as reading the plant tag and following its advice.
Ensure your plants have adequate fertility. Do not over fertilize, especially with nitrogen. Too much nitrogen produces lush succulent growth that is vulnerable to insect and disease attack. It also reduces air circulation, so foliage takes longer to dry out after rain or irrigation. Wet foliage is a perfect home for disease organisms.
Water early in the day so foliage dries out quickly. Where possible, it’s better to use drip irrigation or soaker hoses than overhead irrigation to avoid wetting the leaves. Water is applied directly to where it is needed by the plants’ roots.
2. Provide optimal spacing
Most plants do better if they have adequate spacing, letting them get enough light as well as water and nutrients from the soil. Plants that are crowded and lack good air circulation or are planted in poorly drained soil are more likely to succumb to disease. Think about the tomatoes that were devastated by late blight during the summer of 2010. Those grown in well-drained soil in full sun with lots of space fared much better.
3. Use resistant varieties
Choosing insect and disease resistant and tolerant varieties is such an easy way to avoid problems. Plant breeders have worked hard and diligently to select these plants, so let’s take advantage of their work and use them. Here are just a few examples.
If fireblight has been a problem, select a Thunderchild flowering crabapple. Dropmore linden is resistant to the leaf gall mite that causes the little bumps on linden and basswood leaves.
Some cabbages have greater resistance to flea beetles. Try Copenhagen Market, Early Jersey Wakefield or Mammoth Red Rock. There are also broccoli varieties with flea beetle resistance: Atlantic, Coastal, Gem and Italian Green Sprouting.
Anthracnose can be devastating to cucumbers, but you need not ever have to deal with it if you use resistant varieties: Dasher II, Diva, Fanfare, Sweet Slice and many more.
Sara is the author of numerous gardening books, among them the revised Creating the Prairie Xeriscape. And with Hugh Skinner: Gardening Naturally; Trees and Shrubs for the Prairies, and Groundcovers & Vines for the Prairies. Expect Fruit for Northern Gardens with Bob Bors in November, 2017.
— This column is provided courtesy of the Saskatchewan Perennial Society (www.saskperennial.ca; hortscene@yahoo.com; www.facebook.com/saskperennial). Check out our Bulletin Board or Calendar for upcoming garden information sessions, workshops, tours and other events.
