Page 140 - AG 7-2011 Revised 2016

FALL WEED CONTROL IN ESTABLISHED
LANDSCAPES

By: Gary King Ph.D.

In the fall, weather cools and rains come October through December. This
season is considered by some to be the start of weed management for the fol-
lowing year. Applications at this time and again in the early spring will provide
more yearlong weed control than at any other time.

The focus of weed management in the fall should turn to pre-emergent her-
bicides that will target cool season weeds. A different pre-emergent will be
required, as there are different types of weeds at this time of year. The best
timing for the fall pre-emergent herbicide is before the earliest weed seed ger-
mination. Since the weather varies from year to year, germination may come
earlier or later and can be as early as September in some locations. Soon
after the rains start, it may be too late to stop the sprouting weeds and spot
spraying will be necessary.

Continue using manual or chemical methods of killing established weeds be-
fore they flower or form resistant structures. This time of year is an excellent
opportunity to kill well-established perennial weeds. Hoeing or translocated
post-emergent herbicides may weaken them more in the fall when they are
storing food down in the roots.

Weed control is complicated once plants have well established root systems
and have gone to seed. It’s best to start early with your pre-emergent herbi-
cides and treat promptly throughout the year prior to weeds germinating.

ADDITIONAL WEED CONTROL SECTIONS: IDENTIFICATION-PAGE100

MGMT BEFORE PLANTING- PAGE 112 EARLY SPRING- PAGE 114

AT TIME OF PLANTING- PAGE 118 LATE SPRING- PAGE 122

IN ESTABLISHED AREAS- PAGE 124 MID-SUMMER- PAGE 126

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