Why is my new grass turning colors?

I planted new grass on September 14th, and it’s fully grown in and looking good. However, I noticed a few patches are getting lighter in the past day. Is that just a sign of the season? I’m in Connecticut.

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Have you used Mesotrione?

Shiloh said:
Have you used Mesotrione?

No, the only thing I’ve used is Scott’s turf builder about 3 weeks after planting.

Blair said:

Shiloh said:
Have you used Mesotrione?

No, the only thing I’ve used is Scott’s turf builder about 3 weeks after planting.

Did the bag say it was for Seeding? If so, that’s where the mesotrione came from. It can bleach and change the color of young grass and some of the older grass too.

It’s usually temporary. It might damage some of the new grass, but since you’re 3 weeks post-seeding, it might be okay…

At this point, just let it grow, and it should be green again soon.

@Ben
Yeah, it’s specifically for new grass and includes weed killer.

@Ben
Thanks a lot for the advice!

Looks like meso bleaching to me. If you used Scotts starter fertilizer, it has meso in it.

Whit said:
Looks like meso bleaching to me. If you used Scotts starter fertilizer, it has meso in it.

Oh no, that’s not good.

Blair said:

Whit said:
Looks like meso bleaching to me. If you used Scotts starter fertilizer, it has meso in it.

Oh no, that’s not good.

Why worry? It’s not going to kill your good grass. After a few mowings, it’ll be fine.

Blair said:

Whit said:
Looks like meso bleaching to me. If you used Scotts starter fertilizer, it has meso in it.

Oh no, that’s not good.

No big deal, really. It’s just bleached. I’ve done this a few times, and it grows out with regular mowing.

@RandyJesse
Phew! Thanks for the info.

Someone mentioned it already, but it’s a reaction to the mesotrione in the Scotts starter fertilizer. Your grass will likely bounce back, and hopefully with fewer weeds. It can take up to 3 applications for the tougher weeds to die off.

It’s temporary. Just mow it.

I get this when I don’t evenly spread my ammonium sulfate fertilizer. It goes away in about a week.

A lot of things can change the color—water, fertilizer, stress, etc. It’s usually fine, especially since your grass is still young. Just keep an eye on it.

New grass should be 4-8 weeks old before using regular fertilizer. Starter fertilizer can be used at first to help roots grow, and then you can switch to regular fertilizer once the grass is established.

It’s keeping weeds from growing, which is a plus.

I read on Google that mesotrione can make grass temporarily white. Hopefully, that’s all it is.

“Mesotrione can temporarily whiten grass blades.”

Blair said:
I read on Google that mesotrione can make grass temporarily white. Hopefully, that’s all it is.

“Mesotrione can temporarily whiten grass blades.”

Next time, apply the Scotts ‘Built for Seeding’ fertilizer before watering (as the bag says) at 4 lbs per 1,000 sq ft. It really helps with keeping weeds from competing with your seedlings. Use a different starter fertilizer at 3 weeks, because using too much nitrogen all at once isn’t good for seedlings. Instead, go for 0.25 lb of nitrogen per 1,000 sq ft each week for new grass.