Using Scotts Super Turf Builder Plus 2 after you over-seed is recommended after the grass has reached a certain maturity level. If you over-seeded your lawn four weeks ago, count how many times you have mowed your new grass. At least four mowings are recommended before applying a weed and feed. This maturity indicator is a better way to calculate when it is safe to apply a weed killer. If applied too soon or while it is too hot, newly germinating grass seed can be damaged or killed.
There are two herbicides in Scotts Super Turf Builder Plus 2 weed and feed: 2,4-D and MCPP or mecoprop. These two herbicides work hand-in-hand to give you ultimate control over those pesky weeds growing with your newly over-seeded lawn. Scotts Super Turf Builder Plus 2 will control dandelions and many other common lawn weeds but will not kill grassy weeds, such as crabgrass. 2,4-D and MCPP are post-emergent herbicides, meaning that they will only kill actively growing weeds.
In order for the weed and feed to do its job, the granules must adhere to the surface of the weed leaves. Apply Scotts Super Turf Builder Plus 2 when the lawn is wet with dew or after a steady rain. Once applied, the product should be allowed to work for 24 hours without rain or irrigation. If you are using a Scotts broadcast spreader, set the dial to 3-1/2. If using a drop, or rotary, spreader, set the dial to 5-1/2.
Over-seeding your lawn can help fill in bare patches worn by traffic, drought or a variety of other reasons. Before over-seeding your lawn, make sure to mow the area low where you will be spreading the seed. This will help the grass seed reach the soil surface better. Grass seed must have contact with the soil to germinate. Over-seeding is best done in the fall when the soil is warm but air temperatures are cooler. Make sure to keep your newly seeded lawn moist for seven to 14 days.