September is a transition month in the garden, because the average daily temperature drops by 10 degrees Fahrenheit over the course of the month. This cooldown initiates activity by both the gardener and other critters living in the natural world. While I am busy planting pansies, broccoli transplants, kale, lettuce and radish seeds in my gardens, there are insects equally busy up in the trees, down in the flower beds and in my meadow. During morning walkabouts, I can see where insects nibbled on leaves, and I even come across plants with their leaves completely devoured.
Taking the time to look closer, it is easy to spot the very hungry culprit.
Yes, September is caterpillar season — and it is important to let them enjoy their meal. This is part of the circle of life. This time of year, there is no need to worry about the trees and perennials losing their leaves because they have done their job. Throughout the growing season, the sugars produced in the leaves by photosynthesis were transported in the sap and stored as starch in the plants’ branches, roots and stems.
Come fall, the starch is converted to soluble carbohydrates providing the energy for some trees and other plants to keep functioning during the winter into next spring. Knowing this, I find it easier to allow the caterpillars their fill before they hibernate in leaf debris, in a rolled leaf or within a chrysalis.
Whether a caterpillar, chrysalis or adult, it’s fascinating to learn butterflies have anti-freezing chemicals in their systems to protect them from the cold winter temperatures. To protect the eggs from winter’s wrath, the adults lay them out of harm’s way in sheltered areas. When the warm weather returns so do the butterflies — but only if their winter hiding places in the fallen leaves and other debris are left in the beds until mid- to late March. Understanding how our actions impact their life cycle can save the lives of many beneficial insects, so please let the leaves in the garden be. Leaves also benefit the soil: Chop up the leaves on the lawn to add nutrients to the soil in the form of organic material.
Still, how does a gardener know which leaves are munched on by hungry caterpillars and which are being eaten by garden pests? There is an amazing resource you can use to ID insects other than phone apps like iNaturalist or programs like Bug Guide: It’s the Cooperative Extension System.
This nationwide network of information is supported by each state’s land grant universities. Financed by federal, state and county tax dollars, this partnership is a land grant university–based resource for free information on gardening, farming, insects, plant diseases, home pests, food preservation, and other family and consumer sciences. The system even supports programs for youth through 4-H programs. The cooperative system was initiated in 1862; Virginia joined in 1903. The present-day national Cooperative Extension System was formally established in 1914: It “extends” university research-based information to each community, be it to businesses or a families, at no charge.
Both Virginia Tech and Virginia State are involved in Virginia’s CES — and almost every county has an office staffed with professional agents. On each state’s CES website solid, research-based facts can be found along with contact info for your local cooperative extension office.
Residents can add to their knowledge by joining the Master Gardener, Master Naturalist or Tree Steward programs offered in their county or elsewhere nearby. These groups hold plant sales, seminars, programs, and demonstrations regularly. Trained volunteers answer questions from individuals and businesses on a daily basis.They’ll even figure out what bug is munching on a leaf or why a favorite plant is failing.
I encourage everyone to reach out and get the correct answer to a question at your county’s extension office. It’s just a phone call away and a resource I have cherished for years.
Happy Gardening,
Peggy
