The dirt on soil — it is a precious thing

As of this writing, I have seen far fewer Asian jumping worms on our property than over the past four years. My hands are in the soil every day so I would know. The leaf litter still looks mostly intact and the telltale coffee grounds signature are largely absent. I know it is still too early to be optimistic but I find it odd. I have written before about the infestation and about the damage the worms have done to the property over the past few years (https://www.theungardener.com/articles/dont-look-down). But where have they gone? One might think it correlates to the excessive rain but Peter Groffman from the Cary Institute explained that it is an entirely ‘normal’ process of integration. When the worms colonize an area their populations explode and then they settle in and populations reduce and spread– the food they have devoured is no longer there, also predators become familiar with them as a new food source. This is what is happening here.

One continuing effect of worm invasion is erosion. Over the past several years the worms have loosened the soil. This, compounded by the rain has caused extensive soil erosion, most notably on the sides of a ravine where the soil washed into a stream and then into the Housatonic, taking with it several trees. We felled a massive white pine that was about to topple and take with it a huge chunk of soil that would have then washed away. Dr. Jane Lucas, a soil and microbial ecologist from the Cary Institute is concerned about situations like this. “We are losing soil at a concerning clip- whether by heavy rain that causes topsoil to erode, by compaction from driving on dirt roads, and by leaving bare to dry out. Soil, created over many years, is a precious thing. It is alive, with a microbiome that, like our gut microbiome, contains many of the bacteria, fungus, and other organisms (like invertebrates and viruses) that are the basis for the health of trees and other plants.”

Remembering that soil is alive will guide your actions to keep your soil from degrading. Dried out soil is unhealthy; so is water-logged soil. Soil should stay covered and better to keep soil covered with plants rather than mulch, but mulch is better than leaving it bare. Think twice (or thrice!) about using pesticides or herbicides as these have the unwanted effect of destroying the microbes and other living elements needed for healthy soil. Rather than fertilizing your plants, you want to feed your soil, specifically feeding the microbiome, to keep it healthy and your plants healthy. Compost should not be used in place of soil but can be a useful amendment to soil as organic matter in the form of decaying plant material can help soil retain water and nutrients, reduce erosion, and attract beneficial organisms to the soil.

One person thinking a lot about soil health is Jeff Lynch, formerly grounds manager at Chanticleer who returned to his former hometown this spring to run the gardens at Wethersfield. If you have visited Wethersfield you will recall the several variations of beech trees that have been a signature of the garden. Recently the clipped columns of weeping beech and the allée of beech had to be removed due to beech die-back. Jeff has prioritized soil health at Wethersfield to support trees, both the remaining yet vulnerable beech and other trees and plants. He mixes a custom formula himself which, for the average homeowner might not be practical, but there are products available that have a mixture of fish, kelp and humates similar to what Jeff mixes himself for Wethersfield You can find a selection at Arbico.com

While healthy soil won’t itself cure tree and plant diseases it will support trees in times of stress which can help keep a vulnerable tree alive. (On beech specifically, Jeff and many arborists have been using PolyPhosphite 30 or other phosphite products as a drench during the growing season. https://web.uri.edu/ipm/2022/06/beech-leaf-disease-treatment/ is a helpful from University of Rhode Island) Given current issues with beech, hemlock and now sugar maples, which are losing leaves early either due to scorch or a fungal disease such as anthracnose, perhaps the best thing we can do now is to make and keep healthy soil.

A soil test is a good way to start. There are plenty of labs to choose from; Cornell College of Agriculture offers several levels of testing. Jeff directed me to a new biological test that you can do yourself; it goes a step further than most soil tests to analyze microbes in the soil. The Microbiometer soil test kit measures the microbial biomass and the fungal to bacterial ratio. It is available on their website, www.microbiometer.com.

Dee Salomon ‘ungardens’ in Litchfield County.