How Often Should I Fertilize?

Because you want to fertilize when the lawn is growing, cool-season lawns, such as fescue, Kentucky bluegrass and cool-season blends will need to be fed in early fall (September), late fall (November), and spring (late February/early March). You may want to use one of the low-nitrogen, high-potassium winterizing formulas such as 8-8-25 for your late fall feeding and calculate the rate as 1 pound of potassium (instead of nitrogen) per 1,000 square feet.

How Much Should I Apply?

The general rule is 1 pound of nitrogen per 1,000 square feet. If the fertilizer is 16-4-8, it is 16% nitrogen. To calculate how many pounds of this fertilizer you will need to deliver 1 pound of nitrogen, divide 100 by 16. The answer is 6.25. However, this is just a starting point. If your lawn is growing too vigorously, gradually reduce the amount you apply.

Which Product Should I Buy?

Look for a fertilizer that is at least 30% slow-release nitrogen. That means that the fertilizer granules will dissolve slowly and the nutrients will not wash into the neighborhood creek with the first hard rain.