# Is there a good rule of thumb to know when P and K fertilizer will burn the lawn?



## RangersFC (Jul 29, 2019)

I understand N precautions, but don't know too much about P and K. My soil test results reveal I need a lot of P and K. I was at SiteOne today, and they recommended I use Best 6-24-24 (https://www.siteone.com/pdf/sdsPDF?skuId=123179&resourceId=7413). However, the guy wasn't really sure if it would burn my lawn in the heat. I have Tifway 419 cut at .5in and it's been over 100 degrees all week and will be for the foreseeable future.

Should I wait to correct P and K deficiencies until the Fall when temperatures drop, or would I be fine putting this 6-24-24 down now as long as I water it in thoroughly?


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## g-man (Jun 15, 2017)

All products have a salt index and can cause "burn". The burn is really the roots not being able to get to water. You have Bermuda, so it doesn't really die. Go half rate until weather improves.


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## uts (Jul 8, 2019)

Adding to what @g-man said, take a look at what the fertilizer is made off. It's not just the numbers that matter when it comes to p and K.

E.g for K, if it's made with murate of potash (high chloride content, so high salt index) it has a higher burn potential than sulphate of potash, which has a lower salt index. Based on that you can adjust rates as well. Any fertilizer that utilizes SOP will usually be a little more expensive.


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