Crabgrass facts and control information
There are two basic types of Crabgrass: large crabgrass (Digitaria sanguinalis) and smooth crabgrass (Digitaria ischaemum). Crabgrass spreads by tillering (long runners and shoots) and very prolific seed production, once established crabgrass is very difficult to control in lawns. Crabgrass survives till late summer or early fall but is killed by frost. Crabgrass is a summer annual weed that the germination of seeds is related to soil temperature. Germination of the seeds can take place after soil temperature has reached 55 to 60 degrees F. for a week at a soil depth of 4 inches. Typically in our area; dependant on weather conditions, this can be mid to late March or about the time forsythia begin to bloom.
Prevention is the best means of controlling crabgrass, post emergent control of crabgrass is usually not as effective as pre emergent control since crabgrass is very drought and heat stress tolerant. The pre emergent control should be applied two or three weeks before germination of the crabgrass seeds.
Pendimethalin is a low cost root inhibitor and is moderately efficient in control of crabgrass. It is not a long lived product which should be considered when overseeding is part of your lawn management plan.
Dithiopyr (Dimension) is a very versatile and forgiving pre emergent in terms of timing and efficiency. Product does not leach through the soil and should therefore be applied evenly to prevent skips in coverage. This product should be effective in preventing crabgrass germination up to 120 days.
Prodiamine (Barricade) has the distinction of being the least soluble of pre emergents. It has a very long lasting; over 4 months, control of germination of crabgrass seeds. Because of this residual effect, timing of application is critical for overseeding lawns in the fall-do not apply late in the season!
PREMIUM LAWN PROGRAM
ANNUAL LAWN FERTILIZER PROGRAM WITH
CRABGRASS AND BROADLEAF WEED CONTROL
COOL SEASON TURF MANAGEMENT PLAN
Test soil pH. Apply lime as needed. Add gypsum or humates to loosen hard soil if needed.
MID FEBRUARY – MID MARCH
Application of 18-0-4 Crabgrass Control. Different from 19-3-5, has 25% longer lasting Nitrogen and does not have unnecessary phosphorus. Apply 4 – 5.3 lbs. per 1000 sq. ft. A 50 lb. bag covers 9,000-12,500 sq. ft.
This controls annual grassy and broadleaf weeds as they germinate. DO NOT SEED!
LATE MARCH – APRIL
Application of 15-3-5 Weed & Feed. Apply 4-5.3 lbs. per 1000 sq. ft. A 50 lb. bag covers 9,000-12,500 sq. ft.
Weeds contacted by this product gradually die and disappear from the lawn.
MID – LATE MAY
Application of Beaty Organic Lawn Fertilizer (3-2-3 Analysis).
Granulated and easy to apply, it has a neutral pH, returns microorganisms to the soils, slow release, will not burn turf, totally organic with no harmful chemicals, promotes faster growth with less chance of turf developing brown patch, and no harmful runoff. Apply at rate of one bag per 1000 sq. ft. on new lawns and 25 pounds per 1000 sq. ft. on mature lawns. Water in all applications.
MID – LATE JUNE
Application of 0-0-7 Crabgrass Control. Apply 2.7 – 4 lbs. per 1,000 sq. ft. Will not supply unnecessary Nitrogen and Phosphorus to soil but will contain any crabgrass not controlled by first application of pre-emergent.
An application of Green Up supplies iron and magnesium to your lawn. Maintains a healthy green color without adding unneeded nitrogen. Apply 25 lbs. per 1,000 sq. ft.
LATE AUGUST – SEPTEMBER
Application of Golden Medallion 24-8-12. Apply 4 – 5 lbs. per 1,000 sq. ft. A 40 lb. bag covers 8,000 – 10,000 sq. ft. This fertilizer is the perfect ratio of NPK for this area. It is a 50% Slow Release Nitrogen fertilizer that will feed your lawn well into the fall.
The ideal time to over seed is the middle of September to middle of October
LATE OCTOBER – NOVEMBER
Application of Golden Medallion 18-24-12 Starter/Winterizer. Apply 4 – 6 lbs. per 1,000 sq. ft. A 40 lb. bag covers 6,500 – 10,000 sq. ft.
The real benefit of the two fall applications will be seen next spring.