South Florida Gardening

Japanese Millet Cover Crop

Summer Cover Crops

by , on
Aug 6, 2017

In South Florida our “off-season” is June thru September as the summer months are too hot and humid for most plants to thrive. So for us, this is mainly soil preparation time! After completing the harvesting of our Spring plantings, we allow the soil to rest for a few weeks and then begin planting our cover crops. Of course, we research and plan ahead during the Spring so we have our seeds ready.

Cover crops are any of a wide variety of plants which are planted in the off-season in order to enrich the soil for the coming new growing season. There are many functions that cover crops perform:

  • Most cover crops will fix nitrogen (necessary for green growth) into the soil through their roots. Legumes (beans) are especially good at fixing nitrogen.
  • Cover crops provide valuable nutrients to the soil when the mature plants are pulled up, worked into the soil, and allowed to decompose there. This creates what is called green manure.
  • Cover crops provide natural weed control as they will typically grow fast and choke out most weeds.
Sunn hemp - cover crop

Sunn hemp

We are limited in our choices for cover crops as they must be able to withstand South Florida’s subtropical climate. Some of our choices include the following:

  • Cow peas, also called black eyed peas, do really well although they are vulnerable to aphid infestations. In addition to the nutrients this crop provides to the soil, you have the added benefit of harvesting an abundant crop of nutritious peas.
  • Another legume which does well is sunn hemp. They grow tall and hardy in our blistering heat; they are not grown for the beans here but rather for the roots, stalks and leaves that nourish the soil.
  • We are experimenting with the fast growing Japanese millet this year (pictured at the top), which looks great so far. It looks like a wide-bladed grass and is easy to turn under.
  • Marigolds planted in the summer serve to repel insects and also make good green manure.

Cover crops are an important ingredient for the gardener who wishes to grow food using sustainable and organic methods. The introduction of the decaying matter into the soil produces microbes which improve the soil’s ability to absorb nutrients, a benefit which cannot be overstated. Soil is a living organism that needs a wide variety of life in the way of minerals, bacteria and microbes in order to provide optimum growing conditions.

For extensive information on cover crops:

Good source for purchasing cover crop seeds:

Written by J.K. Photos by D.K. and C.G.