Food for thought

 This week my garden club got together on Zoom to watch a video of a talk by Doug Tallamy. I’ve been a Tallamy follower since 2011, when his book Bringing Nature Home changed my gardening philosophy. Since then I’ve been working on growing more native plants.

 

Insectary bed: flowers and foliage for pollinators and other insects

    In 2019 Tallamy published a new, more prescriptive book, Nature’s Best Hope. He’s marshaling us to rescue biodiversity by creating Homegrown National Park, a combined nationwide habitat for native insects in our backyards. 

    Tallamy demonstrates how we can get the most environmental bang from our native plantings by prioritizing caterpillar host plants. Caterpillars provide the lion’s share of the biomass birds need to feed their young. 

Hummingbirds feeding insects to their chick

Tallamy has identified more than 800 caterpillar species on his 10-acre property in Pennsylvania as he and his wife have replaced nonnative invasive plants with natives (check out his stunning photos of some of them in the new book).

    A light bulb went on for me when Tallamy mentioned that people occasionally write him to point out that an imported species—the Asian ginkgo tree (Ginkgo biloba), for example--used to be native to North America in a previous geological era and claim it’s therefore entitled to native plant status. That doesn’t matter, he said. What’s important is whether a plant supports any native insects. Ginkgoes don’t.

 

Ginkgo is a beautiful tree from Asia-photo Sunroofguy

 
    We’ve come a long way since concern about supporting insects first surfaced. I remember reading in the 1980s about designing a butterfly garden. That was when we planted butterfly bush (Buddleia spp.), which is now out of favor because it’s nonnative and potentially invasive. Butterfly bush and many other flowering imports do serve a purpose, though, providing nectar for bees, butterflies and moths in their adult forms.

Eastern Tiger swallowtail nectaring on a butterfly bush

    As I became more aware of my garden as an ecosystem, I started planting native flowers that provide the right pollen for native pollinators, especially bees. Now we can take the next step and choose to plant for native caterpillars. These aren’t looking for flowers. While adult pollinators can afford to sip nectar unselectively, caterpillars need to eat the right leaves to be able to grow and pupate.

      Because of decades of research in this area, we now know that about 90 percent of insects specialize: they’ve evolved to live off a limited group of plants. Most caterpillars aren’t equipped to deal with the chemical defenses mounted by plant species outside their small group of native host plants.

 

Monarch caterpillars need to eat milkweed

 
    So with data accumulating about which plants host which native insects, we can stop fighting about whether gardeners should plant only native plants. Instead, we can ask which plants host the most insects. Tallamy proposes that we prioritize keystone plants, such as native oaks, willows, cherries, and goldenrods, that provide food for hundreds of species of native caterpillars. How to find these? You can go to the websites of the National Wildlife Federation and the Audubon Society and get lists for your zip code. Somehow this prescription seems much more doable.

 

Native red oak supports more insects than any other local tree-photo Jason Hollinger

 

Oh dear

Wildfires in the West, powerful hurricanes and flooding in the South, and derecho in the Midwest. Meanwhile, the Northeast has been feeling relatively safe. We’ve had a severe drought, but so far climate change hasn’t turned us into refugees. 

    Well, we might not be immune to strange weather events. This Friday saw an unusually early snowstorm that weighed down tree branches still in full leaf. 

Ornamental plum bent low by heavy snow

This happened once before in my memory, in 2011, when a Halloween nor’easter shut down much of the New England. But it’s still far what we expect for the end of October. We’re supposed to be raking leaves and decorating our front steps with pumpkins, not shoveling snow.

    My garden got caught way off guard. All the tender perennials were still in their beds and containers. Now they’re a soggy mess, as is the basil I’d hoped to harvest. 

A pot of herbs. Rosemary made it, basil didn't

 

I wanted to provide blooms for pollinators through November. I don’t know whether the aster flowers will survive after two days coated with heavy snow. 

 

Will these aster blooms last after they thaw?

 
    All I can do is start the process of closing down the garden for winter, though these tasks are coming a lot earlier than I’d expected. When the potting mix thaws, I’ll bag up the elephant ears and cannas and store them in the basement to repot next year. 

 

The canna season has definitely ended

I’d hoped to pick a few more dahlias, but their tubers too will need to be packed away if I hope to replant them in spring. Today the water barrel holds a block of ice. If the weather warms up later in the week as predicted, I’ll empty the barrel and store it in the garage.

    I’m still hoping for some mild days to move compost into newly built raised beds in the vegetable garden. This will be the place for the compost in those aluminum trash barrels I used for food waste, after noticing that fruit and vegetable scraps on the open piles were attracting rodents. 

Composted food waste for the raised beds

If I can’t lift the barrels into the wheelbarrow, at least I can roll them across the yard. That’s the good thing about their cylindrical shape. I’m hoping these contained beds will boost my vegetable harvest. With 3-foot wide beds and 2-foot paths, I won’t walk on the soil around the growing plants, something I couldn’t avoid with my old free-form design. 

Raised beds for vegetables

 
    The other activity for the next month will be relocating fallen leaves from the front of the house to the backyard. Before the snow, I’d fortunately shredded a few for the perennial bed off the deck. There I find finer mulch preferable as new young perennials emerge and gradually expand. 

     For the rest of the yard, I’ll be keeping the leaves whole. Lots is written these days about the advantages of this system. By letting the whole leaves lie undisturbed through the winter, we provide shelter for important native insects that hide there as adults, eggs, or pupae. Plus, it’s a lot less work than bagging or shredding those leaves.