PREEMERGENCE TREATMENTS TO CONTROL WEEDS IN ORNAMENTAL PLANTINGS -- Continued
acre; cost /pound)
Useful for control of seedling broadleaf weeds and to
Preemergence, and poste-
Broadleaf weeds, including
prevent most weeds in plantings of junipers, yews, and
purslane and groundsel.
mergence activity on seed-
dwarf conifers for example. Safe when sprayed only over
narrow-leafed evergreens, but injures the early flush of
growth of spruces and tree firs. A granular mixture of
oxyfluorfen and pendimethalin or oryzalin (grass herbi-
cides) is useful on a broad range of woody ornamental
plants. Oxyfluorfen is of low hazard to turfgrass, unless
applied directly on turf.
It is volatile, and effective only during late fall and winter
Preemergence, primarily in
just before rain or snow. Safe on many woody plants but
annual bluegrass, and
the dormant and cool sea-
not myrtle or boxwood. Dormant applications should be
other winter animals.
followed in the spring with preemergence herbicides for
residual control of annual weeds. Hazardous to turfgrass,
except bermudagrass, downslope unless mulched heavily.
Fails to control annual grasses at the lower rates. Safe on
Simazine (1-3,G,WP, flow-
Preemergence to the
Broad spectrum of annual
many woody plants, certain ground covers, and bulbs, but
weeds for 2-4 months.
able, water dispersible,
no? most annuals and perennials. Susceptible woody
plants include azaleas, boxwood, burning bush, and
flowering shrubs, except at very low rates. Moderate to
high hazard to turfgrass downslope.
Resistant weeds include ragweed, galinsoga, and many
Annual grasses and some
Trifluralin (1-4,EC or G;
Preemergence to the
other broadleaf weeds. Because of high volatility, triflura-
lin requires preplant incorporation in the soil, rain, or
sprinkler irrigation after surface application. It has regis-
tered uses for over 40 herbaceous annuals, perennials,
some ground covers, and most woody plants. It is a good
choice for mixed plantings. A very low hazard to turfgrass