By Carl Wilson, Extension Agent with Colorado State University Cooperative Extension, Denver
Plant this fall to improve your garden soil for next year.
Planting seed in the fall probably seems counter-intuitive to most gardeners. To break down this internal resistance, know that planting a cover crop is easy to do and will deliver a number of benefits.
A popular Colorado cover crop is winter rye grass. It's a natural because it grows well in the warm days of winter, prospers in poor soils and requires only minimal precipitation.
Winter or perennial rye seed can be sown after the vegetable or annual flower garden is cleared following a killing frost. Rake the garden smooth, then broadcast seed at the rate of two pounds per 1,000 square feet. Lightly rake to cover seed with soil and water to settle the seedbed. Generally two or at most, three, fall waterings are enough to germinate and establish the rye.
Allow the rye to grow through the winter. It will keep your soil loose, minimize compaction from rain and snow and prevent soil erosion.
The grass will grow six to 12 inches or more by spring. Many gardeners allow the rye to grow as long as possible before turning it under to maximize their "harvest" of organic matter.
When you're ready to sow your spring garden, mow the grass with a rotary mower to chop the tops into smaller pieces. Then cultivate to turn both tops and roots under. These plant residues quickly break down adding needed organic material to improve soil structure, drainage, and the ability to hold fertilizer nutrients.
You can plant spring vegetable seeds immediately after turning under the rye because the plant residues are non-burning.
Additional benefits of a winter cover crop include gaining two seasons of plant growth for soil improvement in one year, and increasing beneficial microbiological activity through plant root growth in poor soils.
Winter rye seed is inexpensive and carried by many nurseries and garden centers in the fall. Sowing is easy and the effort required to grow and turn under the rye grass is minimal.
If your garden soil isn't all you'd like it to be, can you afford not to plant a cover crop this fall?
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010