Timing is everything. It’s just as true in gardening as in the rest of life. Unfortunately, good timing is not my forté.
There’s a right time to plant certain seeds. On that odd nice spring day, though, I’m likely to be impatient to get things going. I’ll plant seeds in the too-cool soil hoping to get a jump on the season. Instead of getting a quick start, If I’m lucky those seeds will just sit round waiting for the earth to warm up. Often, however, they mold in the cold, damp soil, and I have to start all over.
Similarly, proper timing is important if you’re dealing with insect or disease problems. The right solution applied at the wrong time doesn’t do a dang thing. Usually, that right time has passed before I even notice the problem.
So how’s a gardener to know when the time is right? Phenology. Phenology is a nifty concept that relates the stages in plant development to the development cycles of insects, diseases and other plants. It works because of the way these organisms respond to temperature. A harsh winter, an early spring, a late freeze have a similar effect on the development of plants, insects and diseases.
Happily, some common plants provide a handy guide to when to take action. They’re called indicator plants. For instance, when saucer magnolia flowers start to open, that’s the time to spray trees for eastern tent caterpillars. When the petals are dropping, it’s time to spray your pines for Eastern pine sawfly.
The best time to plant tender vegetable crops such as beans, cucumbers and squash is when lilacs are in full bloom. When lilac leaves open, it’s time to plant peas.
Bridalwreath spirea is a veritable tattletale for the presence of pests. When it starts to bloom, gypsy moth larvae and pine needle scale crawlers are vulnerable to treatment. When the blooms are fading, bronze birch borer larvae are present and elm leaf beetle larvae are feeding.
Even plants some might consider weeds can be indicators. When the first blue flowers of chicory open, it’s time to apply pesticides to prevent damage from the squash vine borer.
I could go on and on, but you’ve probably read enough. How do I remember all this stuff? Get real. I look it up, and it slips from my Teflon-coated brain shortly thereafter.
One source I’ve found is a UW-Extension publication you can download for free by going to learningstore.uwex.edu. Under the Lawn & Garden tab, look for Woody Ornamentals Pest Management in Wisconsin. Starting on page 32, there’s a great explanation of phenology and a table of indicator plants and what they signal.
A more comprehensive resource is “Coincide” by Don Orton. This extremely useful book is the result of Don’s 35 years of field observations as a state nursery inspector. You can check it out at the Spring Green Community Library.
Take it from someone who’s wasted untold time, energy and money planting or spraying when it won’t be effective. Use phenology, instead. Let indicator plants tell you when the time is right, cuz that’s blitz.
Patrice Peltier lives in Spring Green and writes regularly for Wisconsin Gardening, Chicagoland Gardening and The Landscape Contractor magazines. Her work has appeared in Better Homes and Gardens and Midwest Living magazines.