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will scotts starter with weed preventer kill grass seed

1). If you only have a few small areas you want to seed, I have seen folks get around the fact that they have a crabgrass germination barrier in those spots by cultivating the soil to a 4 inch depth (to disrupt the crabgrass barrier), then mixing in an inch of compost like Scotts Turf Builder Lawn Soil, and then seeding with Scotts EZ Seed.

I hear that question quite a few times this time of year. I have two answers depending on the size of the lawn area that needs new grass seed. However, before I give those two answers here is a quick rundown of crabgrass prevention 101.

Now here are my two answers:

Scotts Turf Builder plus Halts Crabgrass Preventer and Scotts Lawn Pro Step 1 contain our best crabgrass preventer to provide prevention for around 4 months. The directions state that you should not plant grass seed for 4 months after application, which means you will need to wait until the end of August to seed. We have a different crabgrass preventer for folks who want to seed in spring and prevent crabgrass. Scotts Starter Lawn Food plus Weed Preventer and Scotts Lawn Pro Step 1 for New Seeding provide crabgrass prevention while allowing you to plant grass seed at the same time. (Note: the crabgrass prevention does not last as long as Turf Builder plus Halts and Step 1, however it is your best choice if you want to seed in spring.)

2). If you have a large area you want to seed, the first recommendation is not practical, so you really need to wait until early fall to seed.

Starter fertilizer is good to use, but it won’t do anything about the weeds.

I think you should kill off as much of the weeds with a targeted week killer like Weed B Gone (or Weed B Gone CCO) before doing anything with seed. If reseeding, the usual practice is to kill everything, water for about a week in order to germinate any weed seeds and then kill it off again. Repeat if possible. Then you are ready to reseed. This will allow you to water and germinate mostly grass instead of grass and weeds.

Are you going to “reseed” or are you going to “overseed”? They are two very different things. It looks like you are intending to overseed, which is a way to thicken your lawn in the fall if you have annual grasses.


If you are going through the effort to redo 20K sf, I would recommend you post lots of pics in this forum first and get some recommendations on a direction. This is a lot of work and it would be a shame to go off in the wrong direction if it can be avoided.

What are your thoughts on using this starter fertilizer? I am planning to reseed a pretty crummy looking lawn that has a lot of crabgrass and foxtail. I plan to scalp the lawn short and bag first, aerate like crazy, then lay the seed. Will this starter fertilizer kill any existing weeds while the seed germinates? Is it worth the cost? I’m dealing with around 20k sf, so trying to find a way to preserve the grass I have (without doing a total kill off with roundup now). Thanks

One more thing to consider when seeding a large area like this: How are you going to keep the seeds moist to get better germination. Grass seeds needs to be kept moist by watering the seeded area every 3-4 hours in the first few days of seeding and then couple of times a day until the grass is established. Do you have a sprinkler system? Or are you going to depend on Mother Nature for watering. In my opinion, tackling this in small sections will be the way to go. Like four 5K sections. To your original question: starter fertilizer will not kill weed seed. In fact it will boost the growth of existing weeds.