February 1996

Winter and Spring Weed Control

David M. Kopec, Extension Turfgrass Specialist

The management of winter weeds is a product of the age of the turf, whether or not you overseed, and where your irrigation goes (wall to wall versus fairway strip overseeding).

By now you should be all done with application(s) of PROGRASS for annual bluegrass on overseeded areas. Areas not overseeded can still receive KERB, which will nix any upcoming seed and existing Poa. KERB will eradicate all cool season grasses, so make sure you apply to dormant bermudagrass only!

Burclover and black medic are controlled by phenoxy-type post emergence herbicides (2,4-D, 2,4-DB, MCPP, MCPA, or dicamba or trichlopyr. CONFRONT is a mixture of turflon ester and trichlopyr together. The trichlopyr is very good on the legume weeds (clovers, medics, etc.).

By the last week in February, you want to have applied a pre-emergence for the southwest cupgrass and crabgrass, which will germinate soon afterwards depending on soil temperature. BARRICADE, PENDIMETHALIN, TEAM, XL, and others are typical dinitroaniline pre-emergence herbicides, which are most effective on grassy weeds. PENDIMETHALIN is also good on spurge control (pre-emergence). DIMENSION has also shown good control for cupgrass and crabgrass.

SURFLAN and XL (surflan and balan) are similar options for warm season turf (dormant bermuda) or tall fescue in high elevation turfs. The active ingredient in SURFLAN will ding ryegrass, and is not labelled for ryegrass or Kentucky bluegrass.

For those up in the mountains who want to spring reseed into their cool season grass (bluegrass, ryegrass fescue), TUPERSAN can be used at the time of overseeding (at the low option rate). Repeat with a second application five weeds later. For new fall plantings or in established turf, use the higher rates in the spring.

Goosegrass germinates about 3-4 weeks later than cupgrass/crabgrass. RONSTAR is very good on goosegrass pre-emergence.

Since our spring-early summers cover an extended period of time, split application options are almost always included on the label. Make sure that you don't exceed the yearly label rate.

If at the lower elevations you want to seed bermudagrass in the third week of May or early June, make sure you go with a "one application program" up front by the third week of February.

Unlike cool season grasses, bermuda will not tolerate TUPERSAN at seeding and it will ding existing bermudagrass as well.

Still have Poa annua? In non-overseed bermudagrass, you can use KERB. Don't get close to cool season turf with it. KERB will eliminate all cool season turfgrasses. Heavily contaminated roughs, fairway edges can be sprayed with DIQUAT, ROUND-UP, or FINALE. When seed-heads flower heavily, collect the clippings when possible.

NOTE: Products are listed as examples only. Other products may exist with other trade names. Inclusion does not imply endorsement, not is absence of similar or other products intentional. Always read the entire label. 

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