The Scotts website question-and-answer section states that grass seeds should be allowed to germinate and grow tall and strong enough to be mowed four times before you apply weed and feed. No entirely specific time period is provided, because different grass species grow at different rates, and growth is affected by many variables, including soil quality, temperature and rainfall or manual irrigation.
Wait for a calm day when temperatures are not expected to rise above 90 degrees Fahrenheit and no rainfall is expected for at least 24 hours. Water the lawn first to moisten the grass, or start the application when the grass is moist from dew. The product should be applied while weeds are actively growing in the lawn. A second application may be made, but wait at least 30 days — and do not use the product more than twice each year.
Timing Is Everything
This turf builder weed and feed should be applied with a mechanical spreader for even distribution. When using a spreader, Scotts Turf Builder Plus 2 spreader settings vary depending on the device. Set broadcast and rotary spreaders at 3.5, hand-held spreaders on 3 and drop spreaders on 5. Even if you’ve used the turf builder products for years, always check the package directions to ensure that the instructions haven’t changed.
Before applying any fertilizer or herbicide product, put on a mask, safety goggles, gloves, long sleeves, long pants and closed toe shoes. After applying the weed and feed and cleaning the spreader, wash your clothing in hot water and detergent to remove any dust or residue.
Scotts Super Turf Builder with Plus 2 Weed Control, now called simply Super Turf Builder with Weed and Feed, contains more nitrogen and phosphorus than plain Turf Builder Weed and Feed, to provide faster green-up. Super Turf Builder contains 29 percent nitrogen, 2 percent phosphorus and 3 percent potassium, while plain Turf Builder contains 28 percent nitrogen, no phosphorus and 3 percent potassium. The active weed-killing ingredients are 2,4-D and mecoprop. Environmental health agencies in some areas list 2,4-D as a chemical known to cause cancer or birth defects, so use with caution.
Some pre-emergent herbicides can safely be used during seeding and usually come mixed with a seed starter. These products have the active ingredient Siduron – also known as Tupersan – that works by suppressing weed seeds while improving root development of the new grass. The fertilizer and pre-emergent herbicide mix is applied with a drop or rotary spreader using a rate of 2 1/2 pounds per 1,000 square feet. The spreader setting and actual application depends on the brand of starter fertilizer plus weed control you use, and you should always follow the instructions found on the label.
Remember that all herbicides are different and the exact time you must wait to apply weed killers to newly planted grass will vary from one product to another. Also, some herbicides cannot be applied to certain species of turfgrass. For best results, always refer to the herbicide bottle’s label.
Herbicides and Seeding
You can control weeds in newly planted grass seed and seedlings without the use of herbicides. Manually pulling the weeds by hand when they first appear keeps them from producing seeds and prevents the problematic plants from spreading, according to the University of California Statewide Integrated Pest Management Program website. They suggest keeping the newly planted grass weed free with proper mowing, irrigation and fertilization. Since newly planted turfgrass has short roots, keep the root zone moist by watering the soil lightly. However, avoid over saturating the soil. After the turfgrass has become established, promote deep and healthy root growth by watering infrequently but deeply.
Weed management should be completed before seeding the lawn with a non-selective herbicide seven to 14 days before you till the soil. A second application of the herbicide may be required to kill any weeds you missed during the first treatment. Wait another seven days until tilling the soil if a second application is used.
Before you plant grass seed, you should always prepare the area by removing any weeds that may be growing in the location. Even with careful preparation of the planting site, weeds can still develop among the newly planted grass seed. Weed killers, however, can harm grass seeds and seedlings if applied too early or improperly.
I have a high traffic lawn from having two dogs. I used a very expensive grass seed for high traffic area’s and then put town Scotts weed and feed turf builder not knowing that you were not supposed to put it down when seeding. I spend a lot of money on the seed and want to know if it is still possible that grass will grow?
The whole idea of using a Weed and Feed product at all is to prevent the germination of seeds. The pre-emergent doesn’t know if they are grass seed or weed seeds, darn it all.
rhizo_1 (North AL) zone 7
I am not that familiar with “Weed and Feed” but assumed it was a broad leaf weed killer designed for weeds like dandylion with broad leaves to take in the product. Fertilizer is included to make it a combination product. If is is a pre-emergent seed germination preventer it is news to me. Read the label on the package to find out. Al