Postemergence

clethodim (Envoy and others)

Dahlia, daylily, and iris

Rate 0.1 to 0.25 lb ai/A

Time Apply to actively growing grasses.

Remarks Identify grasses and adjust rates for susceptibility, and stage of weed growth as label instructs. Add a nonionic surfactant containing at least 80% active ingredient at the rate of 1 pint per 50 gallons (0.25% v/v). Use of crop oil concentrate is not recommended as injury to flower and foliage may occur.

Caution Do not exceed 0.5 lb ai/A per season. Do not apply if rain is expected within 1 hour. Rotational grass crops such as corn and cereals may not be planted within 30 days of the last application. Grazing any plant product or residue is prohibited.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione

fenoxaprop (Acclaim Extra)

Daylily, iris, and peony

Rate 0.06 to 0.17 lb ai/A (13 to 39 fl oz/A)

Time Adjust rates depending on number of grass tillers (see label).

Remarks Ensure thorough coverage to actively growing, susceptible grasses. Repeat after grass begins active growth but do not exceed 120 fl oz/A per season.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxypropionate

fluazifop (Fusilade II)

Daylily, gladiolus, and iris (Idaho, Oregon, and Washington)
Narcissus (Washington only)

Rate 0.25 lb ai/A (16 fl oz/A)

Time Apply to actively growing grasses.

Remarks Narcissus listed on SLN label WA-130007. Identify grasses and adjust rates for susceptibility, and stage of weed growth as label instructs. Results often are erratic on grasses stressed from lack of vigor, drought, high temperature, or low fertility. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment.

Caution Do not exceed 32 oz/A per season. Do not apply if rain is expected within 1 hour. Rotational grass crops such as corn and cereals may not be planted within 60 days of the last application. Grazing any plant product or residue is prohibited.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxy propionate

pendimethalin (Pendulum Aquacap)

Crocus, daylily, lily, iris, narcissus, gladiolus, and tulip

Rate 2 to 3.9 lb ai/A (2.1 to 4.2 quarts/A)

Time Apply after bulb emergence, but before weeds germinate.

Remarks If weeds are present, product may be tank-mixed with a labeled postemergence herbicide. The product requires 0.5 inch of rainfall or irrigation to incorporate within 30 days of application. Use a lower rate on coarse soils low in organic matter.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Dinitroaniline

sethoxydim (Segment)

Dahlia, daffodil, gladiolus, iris, and tulip

Rate 0.28 to 0.47 lb ai/A (36 to 60 fl oz/A)

Time Apply at optimum growth stage listed on label.

Remarks Identify susceptible grasses and add 2 pints/A nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed from drought, high temperatures, or low fertility. Resistant grasses include annual bluegrass and all fine fescues; quackgrass can be suppressed.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Cyclohexanedione