60
PRIMARY
TIMING
vegetative growth flowering seed/dieback dormant root
germination seedling vegetative growth flowering seed/dieback dormant root
PERENNIAL
YEAR TWO +
PERENNIAL
YEAR ONE
BIENNIAL
YEAR TWO
BIENNIAL
YEAR ONE
germination seedling
vegetative
growth
flowering seed/dieback
germination vegetative growth/flowering seedling/rosette seed/dieback
SUMMER
ANNUAL
WINTER
ANNUAL
(1) Non-Selective, (2) Selective, (3) Residual, (4) Surfactant, (5) Pre-emergent
* Summer/Winter Annual: these plants may be found as either summer or winter annuals. If conditions are favorable, seeds may germinate
twice in the same year adopting the seed germination timing of the other annual.
germination seedling rosette
SECONDARY
TIMING
Use the tables below as general guidelines for identifying and treating prohibited noxious weeds and invasive plants with
herbicides by their life cycle. Refer to the individual plant pages for more information about all of the control options and
proper timing of treatments. The first table lists plants by life cycle. Following each plant name are numbers that indicate
the types of herbicides that could be used to control that plant. Some plants are best controlled with
a combination of herbicides. The table at the bottom can be used to quickly look up a life cycle
and identify the general timing of herbicide applications to control a plant with that life cycle.
PLANT LIFE CYCLES AND CHEMICAL CONTROL TIMING
SUMMER
ANNUAL
WINTER
ANNUAL
SUMMER/WINTER
ANNUAL*
BIENNIAL PERENNIAL
LIFE CYCLE TYPE SPRING SUMMER FALL WINTER
APPLE OF PERU (2)
KOCHIA (2, 4, 5)
MILE-A-MINUTE WEED (1, 5)
PALMER AMARANTH (2, 5)
RUSSIAN THISTLE (1, 4)
SHATTER CANE (1)
CRESSLEAF
GROUNDSEL (2, 5)
MARESTAIL (2, 4, 5)
WILD MUSTARD (2)
GIANT HOGWEED (1)
MUSK THISTLE (2)
POISON HEMLOCK (2)
WILD CARROT (2)
WILD PARSNIP (2)
AUTUMN OLIVE (2, 3)
CANADA THISTLE (2, 3)
GRAPEVINE (1, 2)
BUSH HONEYSUCKLE (1, 2, 3)
JAPANESE KNOTWEED (1, 2)
JOHNSONGRASS (2, 3)
KUDZU (1, 2, 3)
NARROW LEAF CATTAIL
AND HYBRID CATTAIL (1)
OXEYE DAISY (2)
PHRAGMITES (1)
PURPLE LOOSESTRIFE (1, 2)
TREE-OF-HEAVEN (2)
vegetative growth flowering seed/dieback
PLANT LIFE CYCLES
CHEMICAL CONTROL TIMING
MARCH 20 JUNE 20 SEPTEMBER 22 DECEMBER 20
x
2
x
2
x
2
