Chapter 16

The Use of Cover Crops to Manage Soil

Life Cycle of Cover Crops

Cover crops are broadly classified as annuals, perennials, or biennials. Annuals complete their life cycle from germination through flowering and death in a year or less. Perennials may persist for three or more years, while biennials exhibit a two-year life cycle. Annual cover crops can be categorized into two main classes: (1) crops that are adapted to cool, short days (i.e., cool-season crops) and (2) those that are adapted to hot, long days (i.e., warm-season crops) (Section 16.6). Growers must select the right species for their particular situation.

Annual Cover Crops

Annual cover crops are chosen for multiple reasons in vineyards. One reason to grow annual cover crops rather than perennial cover crops is to provide seasonal soil conservation in the winter months followed by removing the cover crop by tillage in the spring or the dry season (summer).

Perennial Cover Crops

Perennial species are most commonly used in orchards or vineyards planted on deep, fertile soils where overly vigorous vines are a problem. Orchardgrass, tall fescue, pubescent wheatgrass, meadow barley, California brome, and sheep fescue are examples of perennial grass cover crops. However, perennial cover crops may be more competitive with the trees or vines, particularly in newly planted orchards or vineyards or in shallow or less fertile soils and will have a devigorating effect on the orchard or vineyard.

Biennial Cover Crops

Biennial cover crops grow for two seasons, but don’t actually bloom until the second year. They can be a bit trickier to grow, because they need care over the winter between their first and second growing season. They spend their first year growing the plant and root (as a food source for the plant) and then bloom in year two.

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