bentazon (Basagran T&O, Broadloom)
Rate 0.5 lb ai/A (1 pint/A Basagran)
Time Spring to early summer, depending on growth stage of weeds.
Remarks Use handheld pump-up backpack or knapsack sprayers to direct spray around bulbs, bedding plants and flowers. For control of Canada thistle and suppression of sedges and nutsedge where other options such as clopyralid or S-metolachlor are not possible. For Canada thistle, apply 2 pints/A when plants are between 8 inches tall and bud stage. Apply a second application 2 weeks later if needed. For nutsedge, apply 1.5 to 2 pints/A when plants are 6-8 inches tall, and make a second application 7 to 10 days later if needed. Always add a crop oil concentrate. Use no more than 2 lb ai/A per year. Irrigate to make sure plants are actively growing before applying bentazon. Not as effective if temperatures drop below 50°F at night and in daytime does not exceed 70°F. Efficacy will be poor on drought stressed weeds.
Caution Apply as a directed spray, away from the crop. May apply over the top of some species if crop oil concentrate is not added and application is tested on a few plants to verify crop safety.
Site of action Group 6: photosystem II inhibitor
Chemical family Benzothiadiazole
clethodim (Envoy Plus and several others)
Many bulbs, and flower beds
Rate 0.09 to 0.18 lb ai/A (9 to 32 oz/A) depending on weed species
Time Apply postemergence to actively growing annual or perennial grasses as listed on label.
Remarks For grass control in ornamental plantings. Controls annual bluegrass. Applications made to grass plants stressed by insufficient moisture, hot or cold temperatures, or to grass plants exceeding recommended growth stages may result in unsatisfactory control. NIS required at 0.25%.
Caution Do not exceed 68 fl oz/A per season. Test for crop safety before applying to landscape species not listed on the label.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione
fenoxaprop ethyl (Acclaim Extra)
Daylily, iris and others
Rate 13 to 39 fl oz/A
Remarks Adjust rates depending on number of grass tillers (see label). Ensure thorough coverage to actively growing, susceptible grasses. Repeat after grass begins active growth but do not exceed 120 fl oz/A per season. Inhibits fatty acid production, cell membranes, and new growth.
Caution Determine crop tolerance before extensive use.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Aryloxyphenoxy propionate
fluazifop (Fusilade II)
Alyssum, marigold, petunia, geranium, iris, zinnia, and many others; not for tulips
Rate 0.25 to 0.375 lb ai/A (16 to 24 fl oz/A)
Time Apply to actively growing grasses or within 7 days after irrigation with 0.25% nonionic surfactant when susceptible grasses are in the labeled growth stage.
Remarks Check label for crops that can be injured by over-the-top applications. Identify grasses and adjust rates depending on 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. Inhibits fatty acid production, cell membranes, and new growth.
Caution Do not tank mix with other pesticides. Do not apply within 5 days of other pesticide treatments.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Aryloxyphenoxy propionate
sethoxydim (Segment II)
Rate 0.28 to 0.47 lb ai/A (1.5 to 2.5 pints/A)
Time Apply at optimum growth stage listed on the label.
Remarks Identify susceptible grasses. 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, but quackgrass can be suppressed. Inhibits fatty acid production, cell membranes, and new growth. Many species of bedding plants, ground covers and wildflowers are listed as tolerant on the label, but some have been injured in limited testing such as snow-in-summer (Cerastium tomentosum). Best to test plant tolerance on a small area if tolerance is in question.
Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family Cyclohexanedione