Nesting and Overwintering Habitat for Beneficial Insects

While our gardens sleep for the few winter months we have, what happens to the bees, butterflies, and other beneficial insects that we depend upon during the growing season?

Where do they go? How do they survive the winter? Are there things we can do to provide nesting and overwintering habitat?

A ground nest entrance in a patchy lawn.

While it may seem like the insects have vanished for the year, the vast majority of them haven’t actually gone anywhere. They see your garden as a place of protection from the elements and will display a variety of unique strategies to survive the cool winter climate.

Allow fallen leaves to collect in beds and under trees. Photo by Elizabeth Georges.

Most bees and solitary wasps nest beneath the soil in patchy, bare areas of lawn, while others build cavity nests in places like the hollow stems of plants, old beetle burrows, tree snags, or decaying logs. Bumble bee nests are often found in loose undisturbed soil beneath woody plants, tall grasses, or other dense vegetation. Luna moths overwinter in cocoons, snug in an insulated pile of leaves, while hawkmoths burrow and pupate underground. Eastern black swallowtails camouflage their chrysalids as a dried leaf or a broken twig anchored from a dead flower stem. Other insects such as fireflies, spiders, and beetles seek shelter in leaf litter and rock piles or brush. These are just a few examples of the many insects that will take up shelter in the natural features of your yard.

Having a diversity of native plants is a good place to start when adding overwintering elements to your yard. Consider adding shrubs with hollow stems, such as elderberry, pokeweed, oakleaf hydrangea, and leucothoe; and wildflowers such as dotted horsemint, Joe-pye weed, purple coneflower, ironweed, and asters. All of these plants will provide food for wildlife and nesting sites for a variety of stem-nesting bees.

Leave stumps, snags, and fallen logs for cavity nesters. You can build brush piles with twigs and branches. Photo by Elizabeth Georges.

You can start to cut back spent flower stalks in the spring, but don’t cut them to the ground. Leave a variety of heights, eight to 24 inches above the ground. Female bees will use the cut ends to start a nest. The bee larvae will grow through the season, hibernate over the winter, and then emerge the following spring. It’s a yearlong process so the stalks must stay in the garden, otherwise, you are throwing away your next generation of pollinators. If you must cut back your plant material, keep it in the landscape instead of getting rid of it. Bundle it up or create a brush pile in an area out of the way. Insects will still use the plant if it’s cut and moved. The old stalks will eventually decompose after the insects are through with them, adding nutrients back into the soil.

We’ve been trained to think that a tidy expanse of lawn is the goal, but that lawn doesn’t do much for the birds, bees, butterflies, and other creatures that we share our yards with.Retaining and incorporating as many natural features as possible into your landscape, rather than tidying them away, will help increase the availability and quality of nesting and overwintering habitat. Habitats that connect can have a big impact on a neighborhood scale. One small habitat becomes a large habitat that a diversity of beneficial insects and wildlife can use. Consider putting the pruners up, leaving the leaves, and letting the insects do the work for the future success of their generations and your garden alike.

Plant a Diversity of Oaks This Winter

North Florida and South Georgia are blessed with many species of native oak trees. Two species, dwarf live oak and running oak, form thickets from underground runners and may reach heights of only three feet.

Plant swamp chestnut oak to add diversity and bright fall color to your yard. Photo by Donna Legare.

Some oaks have limited distributions in North Florida. Cherry bark oak and chinquapin oak occur only in Gadsden, Liberty, or Jackson counties along the Apalachicola River.

Others have extremely strict soil requirements, occurring only in deep sand of either present day or ancient sand dunes or sea floors. These soils occur from the present-day coastline to north of Bristol and Blountstown. Drs. Robert Godfrey and Herman Kurz, in their book Trees of Northern Florida (1962), describe two types of sand, buff and white, with certain oaks preferring one or the other. Buff sand is common in inland Wakulla County with turkey oak, bluejack oak, and sand-post oak found growing there, among others. Coastal dunes consisting of white sand support Chapman oak and sand-live oak.

Of the 25 oak species native to our area, only about 10 may be found at local garden centers. Others may be obtained by special request. Usually, these ten species can grow on either dry buff sand, moist lowlands, or rich upland soils.

This young white oak was planted in 2018 to add diversity to Mary Kay Falconer’s Betton Hill’s yard. Photo by Mary Kay Falconer.

This young white oak was planted in 2018 to add diversity to Mary Kay Falconer’s Betton Hill’s yard. Photo by Mary Kay Falconer.

Most people think of live oak when planting an oak in our area for good reason. They are long-lived grand trees. But there are other equally stately and beautiful species that should be used more often, such as white oak, swamp chestnut oak (also called basket oak), Shumard oak, and southern red oak. Laurel oak and water oak are quite common in our area. They are often given a bad rap for weak wood, but both can be strong, healthy trees for at least 50 years, meanwhile providing food for insects, birds, and mammals.

In his recent book, The Nature of Oaks (2021), Doug Tallamy discusses the amazing diversity of animals, primarily insects, which depend on oaks. He writes that native oaks in our nation support 534 species of moth and butterfly caterpillars, more than any other group of trees. Ninety percent of these caterpillars are soft, juicy, high protein food for songbirds and their nestlings.

Native oaks harbor more than caterpillars. Acorn weevils, lacebugs, leaf hoppers, walking sticks, tree cattle, tree crickets, and many other species are part of a valuable ecosystem in the canopy over our heads, usually unnoticed by us. This rich diversity of insects becomes the base of a complex food web.

When choosing an oak to add to your landscape, remember that only native species harbor the huge food web in their canopies. A non-native Japanese saw-tooth oak may provide acorns for deer, but the space taken up by the canopy will be a dead zone for other life. Most native insects cannot utilize non-native plants, due to the presence of different chemicals in the leaves. They need native plants with whom they have shared an evolutionary history.

Leaves in the canopy are not the only valuable resource for wildlife. Oak leaves on the ground below an oak decay more slowly than most other tree species. This leaf litter provides housing, food, and humid conditions for up to three years for insects. For example, Tallamy writes that there can be 90,000 springtail insects in a square meter under an oak. Leaf litter mites may be 250,000 per square meter!

The precious leaf litter under your trees is also critical for giant silkmoth reproduction. After eating leaves in the canopy, the caterpillar drops to the ground to spend a year or two as a pupa hidden under the dead leaves. If your lawn grass extends under the canopy, it spells death for the future beautiful imperial or Polyphemus moth.

Three species of oaks are quite common in our region – live oak, water oak, and laurel oak. For a healthy urban/suburban ecosystem, diversity is key; try planting other species of oaks in your yard. Choose the best oak for your yard based on soil and moisture needs. Some species are very adaptable, others are not. Consider white oak, Shumard oak ,and swamp chestnut oak for their stunning fall color. Mature white oak and swamp chestnut oak also have attractive light gray shaggy bark. Southern red oaks are also stately.

Winter is the best time to plant a tree in our region, while the tree is dormant. Doug Tallamy states, “contrary to urban legend, many species of oak grow quite quickly.” Give your tree plenty of space. Plant three or more trees in a small grove for roots to interlock and create a stronger planting for hurricane survival.

Tallamy suggests planting acorns for the healthiest root structure but admits most of us want instant gratification and squirrels will not cooperate and plant them where we want them. The next best method is to plant an inexpensive bare root seedling or whip. These will also grow a healthy root system.

The third option is to purchase a small one-, three- or seven-gallon potted tree. Roots may be circling in the pot and should be spread out in the hole or pruned off. Circling roots can kill a tree after a few years or will not provide a solid foundation in hurricane winds.

Tallamy’s “bottom of the list” option is to plant an expensive three- to four-inch caliper oak from a large container. The root system will be so compromised that the tree will not have a long life. Unfortunately, government codes usually specify planting large trees for instant impact.

This winter, increase the biodiversity of our urban forest; plant some different oaks and become a part of Tallamy’s “Suburbia National Park.”  Remember they must be American native species!

Bokashi fermentation puts microbes to work in the garden

Microorganisms in bokashi can outcompete bacteria that cause bad smells in a kitchen counter compost bin.

My first real introduction to composting was when my sister, Vanessa, buried some banana peels in our backyard as part of a science fair project in elementary school.

We grew up with a compost pile in the backyard, but mostly just wondered what the funny smell was. Now I have a compost pile in the yard, a bucket for collecting food scraps in my kitchen, and a couple bokashi fermentation buckets outside.

Bokashi is a beneficial mix of microbes on a host medium, often grains or byproducts. It can even be made from spent brewers’ grain sourced from local organic breweries. The first and foremost of the bacteria in a bokashi mix are Lactobacillus.

Once applied to the host medium, the microbes will become shelf stable and have many uses, becoming active in the presence of moisture or food. Once active, the microbes start a powerful anaerobic fermentation.

Fermenting kitchen scraps

Bokashi is a beneficial mix of microbes on a host medium, such as grains.

The main use of bokashi in the garden is in relation to your compost methods. I use a bokashi bucket, which is a five-gallon bucket with a spout attached at the bottom and a lid on top, to ferment many of my kitchen scraps before using its contents. This is often more convenient than dealing with fruit flies or smells from an over aged compost bucket in the kitchen!

We add kitchen scraps to the bucket in layers about two inches deep, and then coat with a few handfuls of bokashi, and finish by sealing the lid tightly. We repeat this process until the bucket is full. Sometimes this will take a while, but the wonder of the bokashi bacteria, is that they will outcompete most of the other bacteria that produce bad smells.

Once full, the bucket will need to be drained periodically until the fermentation is done. This will be at least two weeks, but it can sit for 30 to 45 days. I usually use it after a month, which at that point my next bucket is full and ready to rest.

While resting, the liquid drained can be used as a fertilizer for your plants at a rate of 1 tsp. per liter of water. Use this by watering your houseplants, garden, or general plantings to build the number of beneficial microbes in your soil. These microbes will help unlock the nutrients stored in your soil and mulch.

Adding to compost or garden

Once the fermentation is done, the contents are generally added to our compost pile, again increasing the microbial count in the compost, as well as fighting off unwanted bacteria in your compost pile or bin. The contents of your five-gallon bucket can also be buried directly in the garden or ground.

It should be buried deep enough that the roots of your vegetable plants will not be touching the fermented organic matter, as it will still be very acidic for a brief period. Once emptied, you are ready to wash your bucket and start again.

The great benefit of bokashi composting is it can be done in a small area and used immediately in the garden when buried properly. If you garden and don’t have access to a yard, or live in a small space, this is a great way to use your kitchen scraps and prevent excess input into our landfills.

From houseplants to litter box

Not only is the bokashi useful in the garden, but you can also mulch your houseplants, add to your worm bin, create compost tea, and if you want to get creative, create a fungal mat to add to your compost pile.

My favorite use though is easily in my cat’s litter box. The bokashi’s beneficial bacteria, again, eat up most of the undesirable scent producing bacteria leaving the box much more pleasant to deal with!

Overall, cultivating beneficial microbes for your garden will improve your gardening results. Bokashi is another method of multiplying and adding microbes to your garden, whether it be through small scale indoor fermenting to large scale outdoor compost piles, it will increase your beneficial microbes.

There are many other uses for the microbes around the home and in the kitchen too. Many of the microbes from bokashi are the geniuses behind yogurt! The benefits are undeniable, from the litter box to the garden, bokashi composting and the microbes it supports make your life easier and keeps food waste out of the landfill.