…..Fertilizing fescue in the summer is not recommended. Fertilizing in hot weather robs food from the roots of the grass and makes it more susceptible to drought and disease. Do not be tempted to fertilize a fescue lawn like you would a bermudagrass lawn. If your fescue turns a bit yellow in July, apply a product that contains water-soluble iron (Ironite, etc).
Cyclone spreaders and drop spreaders can both do a good job. Make sure the spreader is set properly to apply the right amount of fertilizer. It is best to apply half of the fertilizer going back and forth on the lawn and the other half while traveling at right angles to the first trip. This will give even coverage so you do not get streaks of yellow and green in the lawn.
We have to keep in mind the big picture when fertilizing turfgrass. All lawns need extra nutrients (fertilizer) during their growing season in order to look their best. Centipedegrass needs very little fertilizer to look good while fescue and bermudagrass need comparatively more. Whether the fertilizer is in granular or liquid form is immaterial to the grass. So how much fertilizer does grass need?
Scientists recommend that one pound of “actual nitrogen” be applied to a thousand square feet of bermudagrass lawn each month during the growing season. What is “actual nitrogen”? It’s the amount of concentrated nitrogen-containing chemical (ammonium nitrate, urea, ammonium phosphate, etc.) that you spread or spray in one application. Remember, a bag of 10-10-10 granular plant food isn’t all fertilizer. Thirty percent is chemical nutrients and the rest is filler material. The percentage of actual nitrogen is what the first of the three “fertilizer numbers” on a bag refers to.
Most gardeners realize that it takes more pounds of 10-10-10 than 29-4-6 fertilizer to feed a lawn. The later has a higher percentage of actual nitrogen. But how much of either would it take to apply the magical “one pound of actual nitrogen per one thousand square feet”?…..
Read more at: https://lee.ces.ncsu.edu/2012/11/fescue-fertilizing/