Chapter 1: An Introduction to Revegetation
Why Revegetate an Area?
Temporary vs. Permanent Seedings
Temporary seedings are intended, as the name implies, to provide immediate but temporary erosion control until permanent vegetation can be established. However, the resulting vegetative mat of annual species may interfere with the establishment of perennial species if the site is not suitably prepared for the perennial seedings. An alternative to temporary seeding could be a loose mulch, such as straw.
Permanent seedings are intended to be used on final grades. The species chosen tend to be long-lived and suitable for erosion control. When practical, permanent seedings should be chosen over temporary seedings.
Annual species can bridge the gap between temporary and permanent seedings. When seed is used, annual ryegrass is often chosen as a temporary or initial cover. A portion of a permanent seeding mix can also be composed of an annual species such as annual ryegrass. In this case, the annual species provides quick temporary cover on the site and may assist the permanent species in becoming established by creating microclimates that foster the germination of seed and protect seedlings from physical forces. Be aware that annual ryegrass has allelopathic properties (a form of natural herbicide) which can be detrimental to certain species.