Time to clean up now! This is a phrase we’re sure your students are familiar with, one that they’ve heard at home and at school countless times. They’re often admonished to tidy up and put things away. But now is the time to surprise them with the opposite message for some parts of the school garden –leave it messy!
We’re talking about the benefits of leaving certain areas of a school garden and landscape a little untidy over the winter. Many gardeners have been taught that fall is the time to head out into the garden to rake leaves, cut down the tops of perennials, and pull out annual plants killed by frost, leaving things neat and tidy for next year’s gardening season. Nature, however, doesn’t always like neat and tidy. In the food garden, it makes sense to cut down and compost most of your plants to help break any cycles of disease or insect problems. But in the flower garden and in the landscape, leaving plant material standing, especially plants native to your area, provides food and shelter to a host of creatures. (Of course, if some of your flowers had pest or disease problems, clean up these plants selectively as you did in the vegetable garden.)
Have you and your students planted a garden to attract butterflies and pollinators? Are there other ornamental plantings around the schoolyard? Letting these areas remain in their natural state over the winter provides sheltering habitat for many overwintering insects, including helpful insects like native bees, butterflies, and other beneficial insects. Many of the insects we try to encourage in our gardens spend the winter in one form or another in dead plant stems or other plant parts, tucked under leaf litter or other plant debris, or nestled in the crown of plants, sheltered from cold, drying winds, and predators. The seeds in dried flower heads also provide a banquet to hungry birds throughout the months of cold weather.
Creating Butterfly Havens
While some butterflies, like monarchs, migrate to warmer climes for the winter, many stay put for the winter at one stage or another of their life cycle. Some ride out the cold months as a chrysalis attached to dead plant stalks or leaves. Others spend the winter as caterpillars sheltered under a layer of leaf litter or snug inside a seedpod. Some species overwinter as eggs attached to plant parts or buried in leaf litter. Some even overwinter as adult butterflies tucked into a crevice, such as beneath the bark of a tree.
Dead plant stalks left standing until new growth begins in the spring also provide overwintering habitat to various species of native bees. Or an overwintering queen bumblebee may find shelter deep in the crown of an ornamental grass plant rustling in the winter wind. A host of other beneficial insects, the garden helpers that help keep pests under control through predation and parasitism, also shelter in or lay overwintering eggs in dead vegetation.
It’s not just insects that will benefit from an “untidy” garden in winter. Leave plants with their dried flower heads standing over the winter to create natural bird feeders for hungry birds. The dried flowers of plants such as purple coneflowers, black-eyed Susans, asters, goldenrod, sunflowers, and ornamental grasses offer tasty snacking for many kinds of birds during months of cold and snow.
Share with your students the reasons behind leaving some garden areas untouched over the winter. Help them to investigate the overwintering strategies of the butterflies and beneficial insects in your part of the country, and learn what kinds of birds spend the winter and might come to dine in your garden space.
If there are parts of the school campus that routinely get a “haircut” or are raked bare in the fall by the maintenance staff, your students might put together a presentation for school administrators and maintenance staff, sharing what they’ve learned about the importance of leaving plant debris for winter habitat and encouraging the adoption of new cleanup routines for the benefit of the many creatures that share your garden space.