- September 5, 2017
Gardens are alive. No matter what time of year, if you quietly listen and watch, you will notice the plethora of activity. From budding flowers in the spring to the rustle of withered seedheads in the fall, our gardens are supporting animals of all shapes and sizes. Here’s a secret not all gardeners know–if you choose to be a messy gardener in the fall and winter–the wildlife value of your garden soars.
Seedheads left on dried flowering plants are a bird’s paradise. Numerous North American song birds eat seeds–finches, sparrows, chickadees, buntings, jays, nuthatches, blackbirds, grosbeaks, etc. One stop in a messy garden packed with dead, seed-filled, native flowers equals a smörgåsbord for resident and migratory birds.
The conditions of winter habitat for migrating birds, it turns out, are a crucial part of their survival and reproductive success in the spring. Savannah Sparrows, pictured above, were studied in their wintering grounds of the southern United States. The birds turned out to be very sensitive to climatic changes in their wintering habitats. In particular, their ability to access reliable food resources essential during long periods of cold or unusual weather influenced their breeding success in the springopen_in_new. Gardens rich in shriveled fruits and abundant seedheads help these migratory birds survive not only winter, but spring breeding.
The same is true for our year-round-seed-eating birds. Bird feeders, especially those that are well-maintained, are a popular hang-out spot for birds in their wintering habitat; but, a messy garden can provide a comparable, more natural foraging habitat. Some native flowers that provide an abundance of seeds in the fall and winter are goldenrod (Solidago), asters (Asteraceae), cone flowers (Echinacea), sunflowers (Helianthus), Coreopsis, and Black-eyed Susan (Rudbeckia). If these species are native to your region and are not in your garden, consider adding them.
Some plants have an extra superpower–galls. Galls are swellings in the tissue of a plant created by insects, fungi, or bacteria. Many species of plants experience galls and play into food chains in unique and sometimes important ways. Goldenrod’s gall story is something straight out of a science-fiction movie.
If you’ve walked in a field of Solidago you may have noticed bulbous structures (pictured right is a dried gall) in the middle of the flowering plant stems. These tumor-like-structures are homes for incubating goldenrod gall fly (Eurosta solidaginis), native wasps (Eurytoma obtusiventris, Eurytoma gigantea), OR beetles (Mordellistena unicolor). The flies will lay their eggs on the emerging goldenrod plant in the spring, the eggs hatch into larvae that burrow down into the stem, creating a nutritious cavity to incubate in until spring when the adult emerges.
This brilliant plan can be thwarted by one of the parasitoid wasps or beetle that can oviposit, or lay their own eggs in the cavity of the developing goldenrod gall fly. (Pictured above is a braconid wasp ovipositing eggs straight into the gall on eucalyptus tree in Australia). If parasitism occurs, instead of a fly emerging in the spring, a wasp or beetle will emerge after a winter feast of the goldenrod gall fly larvae.
The plot thickens, however, as all the insects are vulnerable to the nondiscriminatory predation of hungry woodpeckers and chickadees harvesting the tender, plump larvae of the fly, wasp, or beetle. These larvae provide a protein and fat-rich treat in the middle of a resource barren winter. Yet another reason to leave our gardens messy–to invite the phenomenal life cycles of glorious galls.
And, it’s not just about the birds and the galls. Messy gardens provide habitat to a diversity of other insects. Many species of native bumble bees, mason bees, leafcutter bees, etc. use garden spaces to overwinter. Depending on the species, bees will take winter refuge under a pile of bark or dried leaves, or nest in cavities in hollowed out stems and decomposing logs. Some, such as the native cellophane bee pictured above (Colletes inaequalis), will create burrows in the ground to reproduce and ride-out the cold winter months.
Butterflies can also utilize gardens for overwintering. Species such as the mourning cloak (Nymphalis antiopa) (top left), question mark (Polygonia interrogationis) (top right), eastern comma (Polygonia comma) (bottom left), and Milbert’s tortoiseshell (Aglais milberti) (bottom right) will, amazingly, overwinter as adults. These butterflies find thick piles of leaf litter, a chunk of tree bark, or other cavity to nestle into. Other butterflies, such as the swallowtail and sulphur butterflies will remain in their chrysalis’ overwinter suspended under a dried leaf or tucked away on the ground. When you leave your gardens messy, including ignoring the dried leaves on plants, you help to encourage a rich population of native butterflies and moths in the following spring and summer.
How To Encourage A Messy Garden
Butterflies like the red-spotted purple (Limenitis arthemis), the viceroy (Limenitis archippus) (pictured), and the meadow fritillary (Boloria bellona) have caterpillars that wrap themselves up in the leaf of their host plant during the winter. These make-shift cocoons are hard to spot in the garden but the caterpillar stays protected and in a state of torpor, or deep sleep, until the warm days of spring arrive. To ensure you do not disrupt them, just leave all the leaves where they dry and fall. We recommend waiting until mid-spring to clean your gardens, or after subsequent 50℉ (10℃) days. This provides the caterpillars time to emerge from their torpor to forage or reproduce.
If the butterflies were not convincing enough, hundreds of other critters can overwinter in gardens–assassin bugs, praying mantises, lace wings, wolf spiders, minute pirate bugs, damsel bugs, ground beetles, and ladybugs (pictured eating an aphid). All of these insects and arachnids are considered beneficial, meaning that, as a gardener, you benefit from having them around. As predators, they eat other insects, some of which can be problematic pests in our flower and vegetable gardens. Leaving layers of leaf litter for these animals to burrow under in the winter allows them to get a jump-start on minimizing pest infestations in the spring and summer.
If mammals are your focus, rest assured that squirrels, rabbits, woodchucks, opossums, deer, and others will gladly enjoy the end of season bounty in the form of dried seeds, unharvested vegetables, or the hardy leaves that are tolerating early frost. The presence of small mammals creates likely hunting territory for foxes, coyotes, bobcats, and raptors. A messy garden provides nourishment at all levels of the food chain.
Last, but certainly not least, is the value of helping to shift what we find aesthetically beautiful. Allowing our gardens to be messy for wildlife continues the growing awareness of the value of supporting native biodiversity.
Have you ever taken a moment to see beyond the brown, dried, shriveled flowers and admired the sturdy fragility of a winter garden? This splendor is especially noticeable after the first frost (in areas that experience frost) as the stems and flowerheads are covered in a thin layer of frozen dew. Stunning!
For those that experience regional snowfall, did you know some people actually garden to ensure a pleasing winter garden view? This often entails selecting plants with colorful and structurally resilient stems and seed heads built to stand-up to snowfall. Arching branches of native shrubs displaying frosty fruits, seedheads shooting up from the icy white blanket reminding birds where to land for sustenance, and the vibrant stems of some of our favorite natives assure us that the warm colors of spring and summer will return.
Gardens can be alive all year if we embrace a new paradigm of seasonal lazy gardening. One person’s mess is another person’s gift to wildlife. Go ahead, put away the shears, set-down the rake, pull up a lawn chair, and join us in celebrating the abundance that can emerge from a messy garden.
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