Master Gardener: Fall Tips to Help Pollinators Lifestyles
The blazing autumn in the colorful leaves is a sign that our growing season is drawing to a close.
People love to travel to see these leaves, but when they drop in their garden, they are not that popular. We rake up the last leaf and put them on the sidewalk to be transported.
Hopefully they end up being made into compost and not dumped in a landfill.
However, if you’re a queen bumblebee about to overwinter underground, these leaves make a great blanket. Many butterflies and moths overwinter in the leaves in the form of eggs, cocoons or pupae until spring arrives.
Removing all the leaves from your garden also removes many of the beneficial insects that we have spent the summer trying to attract to our gardens.
What should a gardener do?
The leaves have several benefits for the garden. As well as being a great place for insects and other small creatures to shelter during the winter, they are an excellent source of organic matter when they decompose.
Organic matter can improve the water-holding capacity of soils, improve soil condition and reduce damage caused by drought. Instead of buying compost, use your free leaves.
Leaves can help protect plants from winter winds and freeze / thaw cycles. Start with a 2-3 inch layer of leaves around the plants. Cover the vegetable garden with a layer of leaves to prevent soil erosion.
For the serious composter, having a supply of dry leaves will give you a supply of carbonaceous material to use next summer.
Yes, there can be a downside to too many leaves in the garden.
Some leaves, like maple and catalpa, can form a thick carpet over the garden and potentially suffocate some plants. Voles also love a garden that has a deep layer of leaves as they can use them for running around in the winter.
Finding that balance of what works in your garden can take some trial and error.
I have tried to avoid using mulch – wood – in my garden and letting the leaves sit is one way. They can suppress weeds and retain moisture in the soil.
As the leaves break down, they also add nutrients to the soil. Shredding the leaves first will help prevent them from tangling, but you also cut off any resident insects, defeating the goal.
As for the leaves, this is not a one-size-fits-all solution.
Diseased leaves, as we saw earlier this summer with tar spots and anthracnose in maple trees, need to be removed. Left on the ground, they will be the sources of the disease next year.
A small yard with a large tree may not have enough room to keep all of those leaves on the property.
Can you keep half? A quarter? Can you rake the leaves under a hedge or in a corner?
What about lawns and leaves?
Too many leaves will choke the grass and can promote snow mold in the spring. It can also cause damage to voles in the turf.
When it comes to lawns, mowing the leaves into small pieces is the way to go as it will add nutrients and organic matter to the lawn. Sorry insects!
Of course, if you can reduce the amount of lawn you have, there’s more room for the leaves and all those critters they support.
What else can you do to help beneficial insects and pollinators successfully overwinter in your garden? Besides the leaves, where else do they overwinter?
Native bees nest in cavities or create nests in areas with bare soil.
Bees that nest in cavities look for things like rotten logs, woody stems, hollow plant stems, or dead branches – something they can dig and lay their eggs.
Eggs laid earlier this season will overwinter as larvae, so if you remove these materials now, no bees will emerge next spring.
Bumblebees will make their nests in protected cavities they might find in a stone wall, an old rodent hole, a hollow log, or under a tuft of grasses.
Only the new queens of the bumblebees survive the winter and go through it on their own. They look for a protected place just below the surface of the ground in which they can burrow.
Our native bugs will overwinter in large groups and seek safe places in leaf litter, mulch piles, tufts of grass, or under bark.
If all you have to do is cut back dead perennials this fall, consider leaving some of the stems to the bees so they can use them next spring. They like perennials that have fleshy or hollow stems.
By leaving the stalk thatch at varying heights between 8 and 24 inches, you can create nesting areas, which then become overwintering sites. The stems are not so visible once the seed heads and leaves are gone.
Your garden looks neat and tidy, and the bees are happy too.
Keep the buffet line open – I was able to find over a dozen different flowers still blooming in my backyard on October 1, the majority of which are native plants.
Asters are the big winners when it comes to abundance in October. I have several large plantations of native asters, mostly calico and crooked stem aster, that the bees were going crazy on.
Goldenrod is pretty much done, but there were a few flowering stems here and there – usually with more than one insect species on it.
Helianthus ‘Lemon Queen’, tall coreopsis, mist flower, Jerusalem artichoke, narrowleaf ironweed, phlox, goldenrod ‘Fireworks’ and Heuchera ‘Autumn Bride’, sedum ‘Autumn Joy’ and caryopteris are all in bloom.
If you’ve maintained your gardens to encourage pollinators and beneficial insects, don’t stop now. Keep as many leaves as possible on your property.
Limit the cleaning of your garden so as not to suppress the next year’s generation of native bees, bumblebees, butterflies and moths.
The seed heads are also good sources of food for our wintering birds. Your garden doesn’t have to look messy – you can still tidy things up, but do it thoughtfully.
Keep in mind butterflies, ladybugs, bumblebees and fireflies.
A question about gardening?
The volunteers of the Master Gardeners are normally in the office Monday to Friday, 10 a.m. to noon. Stop by the CCE office at 420 East Main St. in Batavia, call (585) 343-3040, ext. 127, or send them by email to: firstname.lastname@example.org.
On the first Tuesday of the month, join the Master Gardeners of Genesee County for our garden discussions at lunchtime from noon to 12:45 p.m.
Thursday’s program will be “Winter Bird Feeding 101”. This free program will run on Zoom.
Please register on the events page of the CCE website at http://genesee.cce.cornell.edu/ to get your personal link. The programs are recorded and published on the YouTube page of CCE Genesee.