Post-pesticide paradise?

It’s been three years since I stopped authorizing pesticide spraying on our property. As this year's gardening season ends, I’m assessing the effects of that decision.

    After I pulled the plug, the garden wasn’t reduced to stubble by a plague of leaf-chewing insects. But neither did it remain unchanged. I'd sort of hoped that spraying all those years might have done so little that the garden wouldn’t look different without it.

Lush and green in 2013--but with pesticide spraying

    I started the spraying back in the 1990s when I noticed pinpoint white speckles on the leaves of Japanese pieris (Pieris japonica), an elegant early-blooming evergreen shrub. 

Marked leaves of Japanese pieris

A technician from Lueders Environmental diagnosed pieris lacebug, a tiny sap-sucking insect that originated in Japan and has spread around the gardening world. Decades of spraying kept the pieris leaves clean. When we stopped the spraying, the lacebugs came back. New foliage emerging the next spring was shiny and unmarked, but by the end of the growing season, all the pieris foliage was speckled again. 

    After we stopped spraying our many boxwoods (Buxus sempervirens) for psyllids, their leaves too weren’t as well formed and healthy-looking as they’d been with chemical protection. 

Psyllids have inscribed and curled these boxwood leaves

I’d thought the nonnative boxwood shrubs were problem-free. That was a false impression created by pesticide spraying.

    I’d agreed to use pesticides thinking I was protecting my trees and shrubs. Later we added dormant oil spray for hemlock woolly adelgid and Spinosad, a naturally derived insecticide, for winter moth. Those were nonnative insects with no local predators, I argued. I feared that they’d decimate my yard if they weren’t stopped.

A bleak scene: hemlocks dying from woolly adelgid infestation

    Around 2011 I started to get uncomfortable with this approach. Yes, I was targeting problem insects with each pesticide, and the chemicals had each been chosen for least toxicity for humans, mammals and birds. But my newfound concern for the native insects in the yard shifted the frame. I came to realize that no matter how carefully they were applied, these pesticides would always cause collateral damage, killing native insect bystanders that could be leaf-eaters, pollinators, or beneficial insect predators that I wanted to foster and encourage.
 

I didn't want to kill beneficial insects such as this ladybug, seen here eating an aphid

    After gradually cutting down on spraying, in 2016 I finally decided it was time to make a total break with garden pesticides. Regretfully, we had our hemlocks cut down so we wouldn’t need to spray for hemlock woolly adelgid, a particularly pernicious nonnative pest.

The fluffy white balls along these hemlock twigs are woolly adelgid egg cases

    Probably no one but me noticed when, without pesticide treatment, the leaf damage reappeared on the pieris and boxwood leaves. The leaves didn’t change color or drop off. The subtle damage just made me worry that worse was to come.

     Instead, this year the infestations seem less comprehensive. That could mean that without pesticides, the garden ecosystem is rebounding. In a healthy ecosystem, there’s a balance between leaf eaters and their predators. 

Dragonfly on St. John's wort: one of the predators I want to welcome

There’s also plenty of redundancy, so that if one population of insects has a hard year, there are others to fill their role in the community. I’d love to think that’s the ecosystem we’re building here.

Pillars of the community

With winter approaching, most flowers have disappeared from the garden. One family of flowering plants, though, keeps on giving. Asteraceae, the aster family, competes with the orchids for the most populous of all plant families. Flowers for pollinators aren't the only ecosystem services they offer. Lettuce, dandelions, thistles, dahlias, zinnias, and marigolds are all members of this vast tribe.

 

Black-eyed Susans are in the Aster family

    Most flowers in this family are daisy-shaped, from the tiny flowers of goldenrod to huge sunflowers. An older name for the family is Compositae, because each blossom is a composite of many smaller flowers. What looks like a petal of a daisy flowers is actually an individual ray flower. The central disc, where the seeds develop, can comprise thousands of tiny flowers.

 

The central disc of a daisy offers multiple flowers for pollinators to visit

     Walking around the garden this week, I could still spot the brown and black flower heads of asters (Symphyotrichum spp.), black-eyed Susans (Rudbeckia hirta), coneflowers (Echinacea purpurea) and oxeye sunflowers (Heliopsis helianthoides), all North American natives in the Aster family. Flowers of sneezeweed (Helenium autumnale), another cousin, were still bravely opening after a hard frost earlier in the week. I aim to have something blooming for foraging insects throughout the growing season, but this perennial’s performance exceeds expectations.

Sneezeweed flowers opening

    It’s good to have these Aster family members in the garden because they offer a lot to insects and birds. The Lady Bird Johnson Wildflower Center recently zeroed in on the contributions of sunflowers to Texas’ ecology. Sunflowers don’t just provide plentiful nectar and pollen for pollinators and beneficial insects. Extrafloral nectar exuded from stems attracts ants. Beetle larvae over-winter in sunflower stalks. Even wide sunflower heads benefit wildlife by providing cover for quail and grouse chicks learning to forage for food.

Sunflowers offer both food and shelter for native insects-photo Pudelek

    Sunflowers may still be blooming in Texas. Here the blooms are gone. Massachusetts has fewer native sunflower species, but in the cold months it’s easy to observe birds feeding off seeds of daisy-shaped flowers of Asteraceae. In my yard, they like oxeye sunflower seeds and the fat seed heads of coneflowers. I haven’t seen any goldfinches lately—they’re not frequenting my thistle (nyjer) seed feeder--but if some stop by this winter, I hope to see them perching on the coneflower heads I’ve left standing.

    Of course, the Aster family isn’t exclusively altruistic. I notice how good the flowers are at recruiting passersby to transport seed to new locations. A pappus, a hairy or bristly structure, surrounds each fruit and helps it attach to fur or clothing or be wafted by the wind. Picture a dandelion head that releases its seeds to the breeze.

It's easy to see how thistle seeds hitch rides

    I’m determined to grow some annual sunflowers to maturity one of these years. So far my seedlings have consistently been bitten off at soil level before their stems get woody. I blame squirrels. 

A futile attempt to protect a sunflower seedling

I have a “pest-control pop-up,” a 3-foot tall tent made of fine mesh fabric on a flexible frame, that I hope to deploy next spring. Maybe if I sow the seeds and cover the area with the well-anchored tent, I can foil the dastardly sprout-eaters. Hope springs eternal.

Compost shortage

Once my composting operation settled into a routine, I could count on having two of my four bins produce a good supply of fully made compost every year. Every fall I spread a thick layer on the vegetable bed, where organic matter is used up fast by food-producing annual plants. 

Food compost from the closed bin will enrich the soil of the vegetable bed

When I planted new areas, I spread compost on the soil surface before starting to dig. When I learned that harvesting (really mining) peat contributes to global warming by releasing carbon, I started mixing finished compost from the bins with coir (coconut fiber) to make homemade peat-free potting mix.

     This year I haven't produced as much compost as I used to, and I'm going through it faster. Last year I gave away so many potting mix samples that I ran short of finished compost. 

Cute, right?

The reason for the samples was to interest garden club members I met in making their own peat-free mix. I thought if they tried mine, they'd see how easy it is to make a mix that looks, feels and functions a lot like commercial products based on peat. 

     Last year too I piled fewer fall leaves into the bins. I used to heap up leaves on the bins at the end of the gardening season, knowing the fluffy mounds would flatten during the winter, gradually decompose, and become part of the compost. But last year I went big on piling the whole leaves on beds to provide winter shelter for native insects.

Collecting leaves from the sidewalk to pile on garden beds

     Another call on my compost supply last year was the sheet composting project I started last March. The majority of the material for this composting-in-place soil improvement mound came from thick layers of wood chips and fall leaves. Thinner layers of compost were needed, though, to introduce soil organisms that would do the decomposing. I can see that they're doing their work. Already this fall the mound has sunk to about half its original height.

The sheet composting mound is sinking and starting to look like soil

     These extra demands on my compost economy have left the bins nearly exhausted this fall. Cutting down vegetable plants and emptying summer containers, I've started the process again in two of the four bins. According to the old system, though, the other two bins should be full of year-old developing compost. They're not.

The cupboard is bare

     In the past, I've just waited two years for the compost to be finished. Usually I make a point of adding garden waste to the compost as it comes, with no recipe. But I don't want to go through next summer with no finished compost. I may have to adjust my lazy-woman's composting method this year. 

     To get back on track, I can mix shredded leaves with the dead plants in the bins. 

Shredded leaves will decompose faster

Combining "brown" high carbon and "green" high nitrogen components will speed up the process. Desperate times call for desperate measures.

New aesthetic needed

With October gone, the leaf blower season in my area is officially under way. Rain and heavy winds have brought down a lot of leaves, and many homeowners feel those leaves need to be disposed of post-haste. That means blowing or raking every last leaf into a pile and stuffing it into a leaf bag or vacuuming it into a truck to be transported to “away,” wherever that is.

Move 'em up and move 'em out

    Two years ago some local citizens rose up to protest the noise and health risks caused by leaf blowers. Some towns around the country have imposed meaningful limits, and some have even succeeded in passing outright leaf blower bans. But here, the team I was backing lost the fight, or at least the first round. We ended up with a complicated new noise ordinance that still allows leaf blowers seven days per week, with gas models permitted before Memorial Day and after Labor Day. 

After Labor Day, gas-powered leafblowers are free to roar in my neighborhood

I think this means the anti-leaf blower faction underestimated the determination of local landscape contractors to defend their business model. Leaf blower noise continues at a cost to the rest of us: loss of quiet enjoyment of our property. I hope we’ll eventually achieve an ordinance with more teeth.

    If I ran the zoo, we wouldn’t need leaf blowers because we wouldn’t clear fallen leaves from our yards. My town, like many, is stuck with a standard of landscape maintenance that dates to the aftermath of World War II. According to this aesthetic, fallen leaves are whisked out of sight as quickly as possible, and an ideal front yard consists of a swath of neatly mown lawn, as big as possible, backed by a few shrubs planted against the house’s foundation.

Neatness reigns

    As I’ve traveled farther along the path to a sustainable garden, I’ve gotten increasingly comfortable with seeing leaves on the ground. Fallen leaves on garden beds used to look like a mess to me. Now they’re a pleasing part of the view, just the way they’d be on a walk in the woods.

Fallen leaves enhance the beauty of the woods

    I’ve learned there are lots of good reasons to let those leaves lie on the ground. They add organic material to the soil as they slowly decompose, providing nutrients for plants and improving soil structure. They offer shelter for native insects, helping them survive the winter. They act as mulch, minimizing the number of weeds I’ll be coping with the next spring, insulating the soil so a sudden thaw or cold snap doesn’t kill my plants, and helping to hold moisture in the soil for roots to access.

Fallen leaves and pine needles benefit this shady bed

    Now I wonder why my neighbors bother to send away all that valuable organic material and then pay to replace it with mulch or soil amendments. If we send those leaves away, we’re actually depleting our own soil, because what our trees drew from the soil isn’t replenished by decomposing leaves.

Why send away organic material that should become part of your soil?

    But the truth is, I wouldn’t be letting those leaves lie if I hadn’t come to find them pretty. In garden design, neater isn’t always better.