Organic Matter and Soil Quality

There is a lot to talk about this time of year in the garden, but I would like to come back to a theme we have covered a number of times in this newsletter and in my classes.

Organic matter and soil quality are critical to the success of anything that you might grow, and one of the simplest ways to maintain good organic content in your soil is to return organic material instead of taking it away. It is a zero sum game when it comes to organic material in the soil; If you take it away you have to put it back. Annual mulching with a good quality mulch is an important practice, but there are other ways to add material.

Every time you cut the grass and take the clippings, prune branches from trees and shrubs, take leaves to the dump, cut back perennials, and remove annuals, you are taking away organic material that came largely from the soil. Yes, much of it is water, but at some point you have depleted the soil of the critical building blocks for your plants. 

With a health challenge that I had this spring, I had a friend’s company cut my grass for most of the season. Despite my plea, they always took the grass clippings, as they all seem to do. By the end of the summer, with the same fertilization routine and more rain this year, I noticed a significant change in my lawn color and density. The problem was that my organic fertilization program was not enough to keep up with the constant removal of the nitrogen in the grass clippings. With lawns that have had clippings removed for years, fertilization programs have to pick up the slack and often leave lawns not thriving and thin.

Green grass clippings are pure nitrogen, which is fertilizer, and the clippings every week break down to provide organic material back to the soil. I often hear people say that the clippings are messy, but this is only slightly noticeable in the Spring when grass is growing quickly. Most of the year you will never notice the grass clippings that quickly settle down on the soil.

Please ask your contractor, or whomever does your lawn to put your lawnmower on the mulch setting and create a healthier lawn.

Now, I know we have talked about returning leaves to your garden before, so please humor me for a minute.

Every Fall, trees drop their leaves that were created largely from the transportation of nutrients and organic material from the roots to the branches. This is critical material to return to the garden.

A very simple exercise is to line a bunch of leaves along your driveway and run them over several times with your lawnmower to chop them up a little.  It will help them to break down and act better as a mulch.  Return them to your garden in perennial beds or around plants that like a lot of organic material like Hydrangeas, Rhododendrons or Azaleas. This really isn’t a big effort, and is of great value to your garden and the ecosystem of insects.

You can always add a light layer of mulch on top in the spring, but these leaves will break down and help to replenish the soil.

I hope this hasn’t been too preachy, but this is an important issue to create healthy gardens and plants. Check out this UMass Fact sheet on recycling. In everything you do, think about the preservation of organic material. When cutting back perennials, unless they have disease, you can just leave the cuttings in the garden. You won’t even notice in the spring, especially if you cover with some mulched leaves. We need to move away from this idea that our gardens and beds need to be blown clear of every bit of loose material. Clean-ups in the garden don’t have to be taken so literally.