Paradigm shift needed

One characteristic of the post-World War II era was cheery optimism about the potential for solving problems with synthetic chemicals. Perhaps the best example was DDT, which was going to rid the world of insect-borne disease. Look how well that turned out.

Spraying DDT over Oregon forest, 1955

    In the fifties and sixties, we all tended to trust safety and effectiveness claims for household and garden chemicals. Synthetic fertilizer was going to make soil stewardship irrelevant by spreading unlimited quantities of the basic plant nutrients, nitrogen, phosphorus and potassium. We learned that doing this destroys soil fertility while causing dead lakes and rivers as fertilizer runs off fields and lawns into nearby waterways.

Fertilizer runoff causing algae overgrowth and eutrophication

    There was 2,4-D, invented as a defoliant during the war and brought home as Scotts Weed and Feed to eliminate broad-leaved weeds from American lawns. 

     Imagine what would have happened if Scotts had brought home Agent Orange from the Vietnam War—by then, public attitudes toward war materials had shifted significantly. Since the 1940s, 2,4-D has taken us down a path toward increasing insistence on monocultural lawns, with all the water and chemical inputs necessary to maintain them.

Grass doesn't grow this way naturally

    The 1970s brought Roundup (glyphosate), marketed by Monsanto as a benign product to spare us the trouble of bending down to pull weeds. 

Roundup is ubiquitious

By the 1980s, genetically engineered “Roundup-ready” crops resistant to the herbicide enabled spraying this product on agricultural fields. Farmers took up the practice on a massive scale. As a result, we’re all eating Roundup, which a United Nations agency has declared a probable human carcinogen, a hormone disruptor, and a contributor to antibiotic resistance.

    Neonicotinoid pesticides, my garden nemesis, are the next in this series of chemicals first thought to be harmless. From the 1960s to the 1990s, the most commonly used pesticides were organophosphates, which had high toxicity for humans, other mammals, and birds. Neonics are safer for the people applying them, and since the nineties they have dominated the market, used for treating both seeds and growing plants. 

     Now we know that neonics are very persistent in plant tissues and toxic to many insects, including honeybees and other pollinators. 

Neonics poison pollinators

I recently learned that some insects have already developed resistance to neonics. That’s the predictable result of widespread use of any pesticide, analogous to development of antibiotic resistance in treated bacteria.

    Maybe we can stop thinking about living systems in such simplistic ways. Instead of charging in with blunt instruments like herbicides and pesticides, we need to think about what keeps natural systems in balance. Diverse populations and healthy growing conditions help plants to weather the onslaught of pests and diseases. Every organism has its place in a natural community.

Biodiversity protects plant health

    Insect populations are dropping worldwide. We need insects if we’re going to continue living on earth. Times have changed since the fifties. We’ve stopped watching TV Westerns. Let’s also stop thinking of plants and insects as good guys versus bad guys.

Nature or "all-natural" products?

There’s a thriving market for organic lawn care in my town. These contractors offer periodic fertilizing and even pest control with certified organic products. 

Organic lawn service

Intrigued, I met with Jim Agabedis of Minuteman Landscaping in June 2013 to see about switching to lawn care on sustainable principles.

    Jim had a lot of sensible advice to offer. Some was about switching to better-informed practices, such as letting clippings compost in place on the lawn, changing mower blades frequently so they cut rather than tear the grass, weeding by hand instead of spreading weed killer, and aerating sections of lawn where telltale plantain indicates compaction. 

Could the lawn benefit from organic methods?

Another part of his advice was about “product.” That’s where I started to feel ambivalent.
 

    Jim had a compelling story of how he decided to switch from conventional to organic lawn care. He started his business while he was still in college and built it up to 360 accounts. Then an acquaintance shared a one-page article on lawn care without chemicals, and he had an epiphany. 

     Most of his clients didn’t make the transition to organic, but he fought his way back. He said it’s worth it to avoid practices and products that could make people or pets sick. 

Not the approach Jim was aiming for

The lawns his company cares for testify to the effectiveness of his method.

     I didn’t end up hiring Jim’s company. I was looking for weekly lawn mowing informed by organic principles. He was offering something more ambitious: a commitment to a beautiful organic lawn. For me, it’s not worth the money, and it's not the direction I'm heading.
 
    I could see that Jim’s approach was better than conventional lawn care, but I balked at the idea of a lawn, or any other garden area, depending on application of lots of purchased products for health or survival. Jim proposed to apply benign products such as compost pellets and compost tea. 

Spreading compost on a lawn

That’s the organic approach I’d pursue if I had enough time, motivation, and compost to get serious about lawn care. 

     Ideally, though, the compost I’d apply to our lawn would be made up of decomposed materials from our own yard. That way I’d be imitating the natural soil cycle, where organic materials such as leaves and branches decompose on the ground and build soil. 

Organic material cycles back into soil

    I have a problem with replacing chemicals from the garden center or big box store—weed killers, pesticides, synthetic fertilizer—with pricey organic products purporting to fill the same roles. It’s better than the old way, but it’s still a paradigm we should be moving away from.

     Now I see the garden as a community of plants and animals. I aim to enrich and protect it by letting natural processes do their work freely, 

Mountain laurel (Kalmia latifolia) blooming this week

rather than just by replacing synthetic products with store-bought “natural” ones.


This is SEG’s 100th post! Thanks for reading. It’s great to know that we share the same gardening pleasures and concerns.

Life after pesticides

Two years ago I resolved to make a break with pesticides. Well, not a total break, because my hemlocks are still sprayed with horticultural oil for nonnative woolly adelgid, and I still spray for winter moth with spinosad, a natural product derived from bacteria. That was supposed to be all.

    Since I made that decision, I’ve reminded Lueders, the company that does the spraying, that I don’t want horticultural oil sprayed on anything but the hemlocks, and I want them sprayed only in early spring, when insects other than the adelgids are dormant and not in danger of being suffocated by the oil.

White adelgid egg sacs along hemlock twigs. These insects will kill a tree within 5 years

    I convinced myself that I wasn’t going to notice any difference when they stopped spraying other shrubs and trees with the horticultural oil. My reading told me that native insects I’d been spraying for were not going to kill the shrubs and trees. I imagined that the damage they’d do if untrammeled would hardly be noticeable. 

    It’s not turning out to be quite that simple. I’ve already noticed discolored and dying leaves on boxwood. I pruned out some of the worst-looking branches. A few weeks later, more leaves show dots and discoloration. 

Boxwood foliage is yellower than normal, and leaves are stippled with bites

I’d imagined that box (Buxus sempervirens) grew healthily in my garden. More accurately, it looked healthy as long as it got annual spraying.

    With a sinking heart, I noticed last week that scale insects are back on the undersides of the leaves of a variegated kiwi vine (Actinidia kolomikta). I knew they were there last year and hoped I’d eliminated them by swabbing them off the leaves with rubbing alcohol.

White cottony covering protects scale insect on kiwi leaves

    Lueders inspected in March and warned that scale was also affecting two magnolias. I’d noticed black staining on the branches, probably from mold that grew on the insects’ honeydew secretions. 

    So now what? Lueders recommends spraying more horticultural oil. They’d resume treating the magnolias and boxwood in early spring as they used to do, and they’d add a second oil application to the boxwood shrubs in fall.

    The problem is that I’m trying to enable a full population of insects to live in my yard, finding their own balance between leaf-eaters such as the mites and scale and their insect predators. If I keep interfering by applying insecticides, beneficial insect predators won’t be attracted to the garden. 

Dragonflies help maintain balance by eating other insects

Spraying in fall when lots of insects are active would also kill bystanders that are needed as part of the full food web.

    For a start, I think I’ll remove the kiwi vine and replace it with something else that can grow on a north-facing wall. I could try replacing boxwood shrubs with native inkberry (Ilex glabra), which has similar small, shiny evergreen leaves. I’ll hold off on making a decision about the magnolias. 

     I’m thinking of this period as analogous to the transition from conventional to organic farming. It could take a few seasons for a natural balance to be established.

    Here’s hoping that won’t mean losing those lovely magnolias whose flowers raise our spirits in early spring.

Star magnolia (Magnolia stellata) in late April