Each application should be approx 1 pound of N per 1,000 ft2. Therefore, N+S yards require approximately 20 pounds of N. If the fertilizer you are using is 25-X-X, then 80 pounds of fertilizer would be required.
Purchased 10 pounds of Spectro 90 WDG from Amazon for $86. Must be dissolved in water and then spayeqd over lawn. Disperse 5 oz. (weight - not fl. oz.) S90 per 1,000 ft2. Application rate for S90 in solution is 2-4 gallons / 1,000 ft2.
Created sprayer by putting sump pump in 55 gallon drum and attaching a sprayer and hose to the pump.
Method: 1) determine area to treat, 2) calculate amount of S90 to use, 3) calculate amount of water needed for solution.
North Yard - 3,980 ft2. Round to 4K. Apply 20 oz. (1 lb. 4 oz.) S90. Dissolve in approx 16 gallons of water. Apply.
South Yard - 8,881 ft2. Round to 9K. Apply 45 oz. (1lb. 13 oz.) S90. Dissolve in approx 36 gallons water. Apply
Do not use 2,4-D, dicambra, or mecoprop on St. Augustine.
Feb 1, 2016
Brown spots from last year are much worse. Many weeds appearing in areas where grass is weakened or dead. Have not treated with fungicide since probably Nov 2015. Treatment at that time was spot treatment only with Bayer Fungus Control for Lawns. Treatment with same in Spring of 2015 seemed to help a good bit. Nov 2015 treatment caused no noticable improvement.
Applied 3.75 pounds of Spectro 90 WDG fungicide to entire yard.
Treatment lasts 3-4 weeks. Re-apply Mar 1, 2016.
Feb 9, 2016
The brown spots are terrible. Approximately half the yard is affected. Cut grass. Applied 35 pounds Hi-Yield Weed and Grass Stopper with Dimension.
Will not work properly if no rain or not watered in within 30 days. So, wait a week or so; if no rain, water.
Feb 10, 2016
Treated weeds in driveway with Compare-n-Save (CNS) Concentrate Grass & Weed Killer. 41% glyphosate. 3 ounces per gallon of water in sprayer, plus dye. Used 4 gallons of mix to treat driveway.
If this doesn't kill weeds, next step is Pramitol 25E Herbicide. Apparently kills everything and prevents regrowth for 1 year.
Feb 16, 2016
Dollar weed (aka Moneywort, Pennywort) has been proliferating all winter. Some spots where the grass died last year are covered with it. The WGS applied on 2/9 does not kill dollar weed.
Spot treated entire yard with Atrazine. 4 oz. in 1 gal of water. Hand applied to dollarweed.
Will be interesting to see how the St. Augustine is affected by the Atrazine, if at all. Atrazine is approved for use in St. Augustine.
The mixture appears to bead up on the dollarweed leaves, rather than evenly cover them. If this applicaiton doesn't work, perhaps try next time with a surfactant or sticking agent to get full coverage of the leaves.
Note: Just read that you can use liquid dish detergent as a surfactant. However, if the detergent isn't a non-ionic surfactant, it may affect the herbicide's chemical process. Therefore, some recommend against using dish liquid and suggest using something tailored to herbicides, such as Hi-Yield Spreader Sticker (which is a non-ionic surfactant).
Feb 28, 2016
A few of the treated dollarweed look like they are dying, but most (98+%) look just fine. Should probably reapply Atrazine with a surfactant.
Feb 29, 2016
Reapplied Atrizine. Three gallons total, with spreader/sticker and dye. The 3x higher rate of application along with the spreader sticker should improve results.
March 13, 2016
Reapply Spectro 90 at rate of 5.0 oz / 1,000 ft^2.
March 4, 2017
Do not use 2,4-D on St. Augustine. Same goes for dicambra and mecoprop.
Lots of clover, carolina geranium, dollar weed (or dichondra?).
- Gordon's PRO Speedzone Southern
- (carfentrazone-ethyl 0.54%, 2,4D 10%, MCPA 2.6%, dicamba 0.67%) Seems to have the best reviews for the above weeds. $87/gal/domyownpest.
- Gordon's Speedzone Southern
- (carfentrazone 0.62%, 2,4D 28.5%, MPPA 5.8%, dicamba 1.7%) NOTE: this is not the same formula as speedzone southern above! 20 oz. bottle. $35 on amazon. >>>>>>>>>>>>>>> NOT FOR USE IN ST. AUG!
- Fertilome Weed Free Zone
- (2,4D 10%, mcpa 2.6%, dicamba .67%, carfentrazone 0.5%) $30/16oz/domyownpest, $35/32oz/amazon. Seems to be same composition as PRO speed zone.
- Bonide Weed Beater Ultra
- (MCPA 31%, MCPP 6%, dicamba 2%, carfentrazone 0.2%) $30/16oz/domyownpest, $22/128oz/amazon
- (MCPP, 2,4D, dicamba) >>>>>>>>>>>>>>> NOT FOR USE IN ST. AUG!
March 8, 2017
Earlier weed ID was mostly incorrect. Lawn has the following: Carolina Geranium, Catchweed Bedstraw, Gound Ivy, Henbit, Hop Clover, Wild Violet, and Oxalis Carssipes.
Purchased Fertilome Weed Free Zone from Amazon. They say 0.75-1.5 ounces/gallon. However, they also warn against use on St. Augustine when lawn changing from dormant to growing. I used anyway - 1oz/gallon of water. Also added 1oz/gal MSO and 1oz/gal dye. Was out of spreader/sticker and completely forgot about it. Applied 4 gallons to North and South yards.