Gardening

As garden season winds down, plant green manure cover crop

It’s not your imagination, the growing season is winding down early this year. The excessive rain and cooler than normal temperatures in our area have combined to make it a challenging season for many garden plants, especially the warm weather crops like tomatoes or peppers.

Farmers are noticing it too. Many field crops never fully recovered from poor start of the season and are showing signs of maturing early. As a result there may be a reduction in yields as well.

Certain beds in my garden are already kaput. But there is a silver lining in that. It gives me a chance to plant a green manure crop, which I don’t often get to do.

The terms green manure and cover crop are basically synonymous. Green manure is a crop that will be turned over into the soil while still growing, a cover crop may or may not be turned into the soil right away.

These types of crops are great for recovering soil nutrients from the soil and holding them until next year’s planting season. Some soil nutrients such as nitrogen are easily washed down into the soil profile by fall rains or melting snow putting them out of reach of most garden plants. Much of that valuable garden nutrients that you worked so hard to build up could be lost.

Multiply the nutrients over hundreds of acres and you can see why farmers use cover crops to save money and protect the environment at the same time. Nutrients that stay in the field will not get washed into steams and rivers where they end up being a source of water pollution.

In other words, green manures effectively “mop up” nutrients and hold them in place until they are needed next year.

In a garden situation, the biomass that a green manure crop adds to the soil may be more valuable than the nutrients they conserve. You really can’t have too much organic material in garden soil.

A cover crop also provides a better habitat for soil microbes to flourish as opposed to bare soil.

Planting cover crops is a fairly advanced technique for home gardeners even though it is very effective for both vegetable and flower gardens.

If this is your first time planting cover crops, consider oats  —  yes, the same plant that is harvested and used for making your breakfast cereal. They make a very effective cover crop.

Oats grown for livestock feed, right off the farm, is acceptable for planting as a green manure cover crop.

Oats grown for livestock feed, right off the farm, is acceptable for planting as a green manure cover crop.

This time of the year we are looking for a plant that will make quick growth and oats fit the bill. Even though they grow quickly, they should be planted very soon.

The other big advantage that oats have is that they will die over winter leaving a mulch on the soil surface that can be tilled in next spring. That also eliminates the possibility that they may become a weed in your garden. I’ve had winter wheat come up in the spring — seeds from straw mulch — and before I knew it they became a problem. Have you ever tried to pull up a well established clump of wheat? They’re pretty tough plants.

Planting oats is much like planting grass seed except the seed is much larger.

Sow oats at a rate of 2 or 3 pounds per 1000 square feet about an inch deep. Farmers use an implement called a seed drill to plant oats. The easiest method for a gardener is to broadcast the seed by hand, then till very shallowly with a tiller. Finish off by lightly pressing the area down so the seeds make good contact with the soil.

Farm supply stores sell oat seed however you may have to go online to buy small quantities.

Bob Dluzen
As a result of being a gardener for more than 40 years, 30 of those as a professional, Bob's gardening has become an integral part of his life. "It's the ever-changing seasons and the wide variety of plants and gardens that keeps me intrigued," he says. Bob lives and gardens in rural Monroe County.