Trade name(s) Dimension EC, Dimension EW, Dimension Ultra 40 WP, Lifeguard
Manufacturer(s) Dow AgroSciences
Formulation(s) 1 and 2 lb/gal emulsifiable concentrate and 40% wettable powder
Remarks Selective control of many annual grasses and certain annual broadleaf weeds in established cool- and warm-season turfgrasses in lawns and ornamental turf.
Water solubility 0.7 ppm
Storage conditions Store above 32°F.
Acute toxicity LD50 - more than 5,000 mg/kg
Action in plant Interferes with cell division.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Pyridine
Koc Average is 1638 mL/g
Tim Prather
Revised March 2012
Total vegetation control with soil-residual herbicides is a process in which the addition of chemicals renders the soil unfit for plant growth. Soil-residual herbicides do not kill all animal and microbiological life in the soil.
Keep the following in mind when using soil-residual herbicides:
Ed Peachey
Revised June 2012
Multiply rate by 0.023 for amount per 1,000 sq ft
BULB AND FLOWER BEDS—Preemergence, Soil-applied Treatments
dithiopyr (Dimension 2EW)
Iris, tulip and lily
Rate 0.375 to 0.5 lb ai/A (0.75 to 1 quarts/A)
Time Apply preemergence around bases of bulbs in landscape.
Ed Peachey
Revised June 2012
Multiply rate by 0.023 for amount per 1,000 sq ft
geo-textiles
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.
Ed Peachey
Revised June 2012
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.
Ed Peachey
Revised June 2012
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.
Gwen Stahnke
Revised March 2013
TURFGRASSES—Influence of Cultural Practices on Weed Encroachment
Poor turf culture is a major reason for weedy lawns. Any effort to control weeds in turf should start with improving cultural practices. One goal of cultural weed control is to maximize turf density and maintain healthy, disease-free turf for a major part of every year. Some of the most important cultural practices are discussed below.
Ed Peachey, Tim Miller, and Andy Hulting
Revised March 2013
This information provides specifications for users of this handbook. For more information regarding the physiological or biochemical activity and behavior in or on soils, refer to the Herbicide Handbook of the Weed Science Society of America.
