Lawn Fertilizer Question ??

[James]

I live in Northeast Florida, and have St. Augustine grass. I usually fertilize in late March, and around mid-September.

When I fertilized in March, I could see the grass turn greener and start growing faster within about ten days. The difference was very obvious.

When I fertilized again three weeks ago, I ran out of time, and only got to half my yard. Thus, I can easily compare where I have fertilized and where I haven't.

I can't see ANY difference whatsoever as to where I put down new fertilizer and where I haven't. The area fertilized has not greened a bit, and the grass blade growth rate is no different than the areas where I did not fertilize. In short, this fertilizer has had NO effect on my lawn. After three weeks, I should see obvious greening, and obvious growth enhancement, but I don't.

I used Scott's Turfbuilder. I don't recall the exact formula, but it was something like 24-8-16. I spread it at the recommended rate, watered it in, and the lawn has had an inch of rain per week during these three weeks. Our daytime temps are still in the high 80's to low 90's, so the grass is still growing.

I don't see much point in now fertilizing the other half, if this application has shown no reponse.

Does anyone have any idea of why I am experiencing this with my lawn ? By the way, the lawn looks pretty decent, considering the fact that the prior feeding was back in March. It is relatively green, and growing normally, although at a slowed rate. I don't seem to have any decline, insects, or fungus. I just don't know why it doesn't seem to respond to fertilizer.

I will appreciate any ideas or comments.

Thanks !!

--James-

[World Traveler]

James -- I'm in Central Florida, and have noticed that turf has slowed down a lot in the last few weeks. I can only guess at your circumstances, but in general you don't need to fertilize when your lawn is going dormant -- and your question raises a couple of other comments --

For Florida, the preferred fertilizer has a smaller ratio of nitrogen than the numbers you cited, and most/all of that nitrogen should be insoluble. (Also, most of Florida has sufficient phosphorus and don't require a fertilizer that has more than 2% phosphorus. For most of Florida, something like a 15-0-15, with most of the nitrogen being slow release, is the preferred product.) Don't trade off near term lush leaf growth for long-term plant strength and root growth. With too much nitrogen you'll get a lot of soft leaf growth, which doesn't help the plant overall, and attracts raiding insects.

(Sidebar: that's one reason that a weed-and-feed is not recommended in Florida. To counteract the harmful impact on the turfgrass of the "weed" component, a weed-and-feed is very high in nitrogen, mostly soluble nitrogen, so that the turf damage is masked.)

Lesco makes a couple of good professional Florida fertilizers. Some of the national brands, sold at retail chains, may be good elsewhere, but are not optimized for Florida's unique subtropical climate.

Bottom line -- get hold of a copy of the Florida Yards and Neighborhoods guide for homeowners, which has really good information on how to maintain turfgrass in Florida. It's available at your extension service or can be downloaded from

Your extension service and Master Gardener program will also have a couple of other good references on Florida's special requirements. There's more material available at hort.ufl.edu/fyn/

In most places in Florida, you can get a member of the Florida Yards and Neighborhoods (FYN) program to come to your location and suggest optimum (and environmentally sound) gardening and lawncare procedures.

[James]

World Traveler, thank you very much for this info.

--James--