Weed Management and Invasive Species Control - Project Planning and Management for Ecological Restoration - page 191

Weed Control Strategies in Degraded Natural Areas
A creative and effective approach to weed control was developed in Australia by the Bradley sisters,
who were working on bush regeneration (Bradley 2002). This sequence of steps is even suited for one
person doing hand weeding. However, if you have several people available, you can divide up your site
to take advantage of the increased labor. The first underlying principle is to always begin weed control
in relatively undisturbed natural areas and then gradually clear toward the more heavily invaded areas,
allowing time for native vegetation to move into cleared areas. The second principle is to try to keep
from disturbing the soil any more than necessary while removing the invasive plants, because undis-
turbed native soil with mulch resists the establishment of invasive plant seeds. This approach is useful
for areas with limited budgets, motivated volunteers, and plenty of time to accomplish established
goals. Applying the following sequence of steps is best for the eradication of weeds in, and adjacent to,
natural areas being encroached upon by invasive plants, but it can also be used on restoration sites.
WEED ERADICATION: BRADLEY METHOD
1. Prevent deterioration of areas not experiencing weed infestation. Start by getting rid
of weeds that occur singly or in groups of four or five in areas where native plants are
dominant. Check once or twice a year for missed weeds. Depending on the species of
weeds and their ecophysiological characteristics, checking may need to be more frequent.
2. Improve the next best. Choose a place that you can visit easily and often, where the native
vegetation is pushing against a mixture of weeds and natives, preferably not worse than
one weed to two natives. Start with a strip about twelve feet wide and no longer than what
you can cover about once a month during the growing season. Give the natives time to
move into the weeded areas. If this boundary is on a steep slope that might erode, clear
a number of patches instead, but still no more than twelve feet from the vigorous native
vegetation. Let a few months go by before you lengthen the strip. Your experience will
dictate whether to make the strip longer or shorter.
3. Hold the advantage gained. Resist the temptation to push deeper into the weeds before the
regenerating natives have stabilized each cleared area. The natives need not be very tall
but should form a dense groundcover. The Bradleys recommend excluding light from the
ground—a very important factor because weed seedlings consistently appear in bare soil
at the edges of paths and clearings, even when relatively undisturbed and surrounded by
dense native vegetation.
4. Cautiously move into the extensively infested areas. When the new growth consists
almost entirely of native species with only a few weeds, it is safe to move farther into
the weeds. Do not start to clear a block of solid weeds until you have brought the good
native vegetation right up to that area. Solid infestations of weeds can be worked on at the
edges by forming peninsulas of weeds, small clearings less than six feet in diameter. Also,
conduct spot weeding: removing a single large weed plant next to a native plant enables it
to grow faster. There is no reason to hurry this process; much more is gained by allowing
the native plant to establish well before removing other adjacent weeds.