Trade name(s) Poast, Poast Plus, Prestige, Vantage

Manufacturer(s) BASF, Nufarm

Formulation(s) 1, 1.3, and 1.5 lb/gal emulsifiable concentrate.

Remarks A selective, postemergence herbicide to control most annual and perennial grasses. A crop oil concentrate enhances activity.

Water solubility 4,700 ppm at pH 7

Storage conditions Store between -4°F and 86°F in sealed containers.

Acute toxicity LD50 - 4,900 mg/kg

Action in plant Inhibits growing points of grasses.

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

Chemical family Cyclohexanedione

Koc Average is 100 mL/g (estimates) at pH 7


Rick Boydston
Revised March 2014

ASPARAGUS—Seedbeds and Early Establishment

See “Section N. Vegetable Crops: Site Preparation, Stale Seedbeds, and Selective Postemergence Applications” for additional options for weed control during asparagus establishment.

clethodim (several trade names)

Rate 0.07 to 0.12 lb ai/A

Bulb and Flower Beds

Ed Peachey
Revised March 2014

Multiply rate by 0.023 for amount per 1,000 sq ft

BULB AND FLOWER BEDS—Preemergence, Soil-applied Treatments

dithiopyr (Dimension 2EW)

Except Easter lily and gladiolus

Rate 0.375 to 0.5 lb ai/A (0.75 to 1 quarts/A)

Time Apply preemergence around bases of bulbs in landscape.

Established Tree, Shrub, Rose, and Ground Cover Landscapes

Ed Peachey
Revised March 2014

Multiply rate by 0.023 for amount per 1,000 sq ft


Available at agricultural and garden supply stores

Spun-bonded fabrics (non-woven) lightweight, extruded polypropylene fibers; requires mulch cover due to moderate UV light sensitivity; weed roots and rhizomes can penetrate fabric unless removed before establishment; cheapest option.

Ornamental Bulb, Rhizome, Corm, and Tuber Crops

Tim Miller
Revised September 2013

Daffodil, dahlia, gladiolus, iris, lily, narcissus, tulip, and peony

Conifer Seedbeds

Ed Peachey
Revised December 2013

Conifer seedlings are extremely poor competitors during the first 2 years in a seedbed. Consequently, it is imperative to select a site that contains few weeds, or weeds that can be controlled with current technologies. Complete elimination of all perennial weeds and proper seedbed preparation is essential. Constant surveillance coupled with regular and timely weed control practices is required to maintain weed-free seedbeds and nurseries. Consult labels for tolerant crops.

CONIFER SEEDBEDS—Preemergence Control before Conifers Germinate

Weed Control in Field-grown Nursery Stock

Ed Peachey
Revised December 2013

Weeds compete with newly planted nursery stock. Deep-rooted perennial weeds can reduce vigor and render a mature product unmarketable due to laws on transporting noxious weeds. Consequently, weeds are controlled with herbicides either broadcast-applied in closely spaced crops, or within the tree or shrub row for wider spaced crops, with alleys being mowed or flailed.

Weed Control in Container-grown Nursery Stock

Ed Peachey
Revised December 2013

Sanitation The first step to effective weed management is sanitation. Start with potting mixes that are free from weed seeds. Control weeds that have wind-dispersed seeds around the perimeter of the site. If weeds emerge in containers, remove them before they produce seeds. The more weed seed allowed to contaminate containers, the higher the probability that the weeds will germinate in areas where the herbicide barrier has been weakened or disrupted.

Tomatoes, Peppers, and Eggplants

Ed Peachey
Revised March 2014

TOMATOES, PEPPERS, AND EGGPLANTS—General Weed Management Strategy


Ed Peachey
Revised March 2014


glyphosate (many products)

Rate Consult label

Time Broadcast before crop emerges; after crop emerges use hooded and shielded sprayers in row middles, and wiper application in row middles.

Peas (Green or English)

Tim Miller
Revised September 2013

PEAS (GREEN OR ENGLISH)—General Weed Management Strategy

Peas are drilled in closely spaced rows early in spring, which limits weed emergence and species diversity. Most growers apply herbicides to suppress or eliminate weed competition, or potential contamination of harvested product. Subsequent crop rotations during the same season limit herbicide choices to those exhibiting brief soil residuals.

PEAS (GREEN OR ENGLISH)—Stale Seedbed Method

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