June is the time to fertilize warm-season lawn grasses such as 
bermudagrass, buffalograss, and zoysiagrass. These species all thrive in 
warmer summer weather, so this is the time they respond best to 
fertilization. The most important nutrient is nitrogen (N), and these 
three species need it in varying amounts.

Bermudagrass requires the most nitrogen. High-quality bermuda 
stands need about 4 lbs. nitrogen per 1,000 sq. ft. during the season 
(low maintenance areas can get by on 2 lbs.). Apply this as four 
separate applications, about 4 weeks apart, of 1 lb. N per 1,000 sq. ft. 
starting in early May. It is already too late for the May application, 
but the June application is just around the corner. The nitrogen can 
come from either a quick- or slow-release source. So any lawn fertilizer 
will work. Plan the last application for no later than August 15. This 
helps ensure the bermudagrass is not overstimulated, making it 
susceptible to winter-kill.

Zoysiagrass grows more slowly than bermudagrass and is prone to 
develop thatch.
Consequently, it does not need as much nitrogen. In fact, too much is 
worse than too little. One and one-half to 2 pounds N per 1,000 sq. ft. 
during the season is sufficient. Split the total in two and apply once 
in early June and again around mid-July. Slow-release nitrogen is 
preferable but quick-release is acceptable. Slow-release nitrogen is 
sometimes listed as “slowly available” or “water insoluble.”

Buffalograss requires the least nitrogen of all lawn species 
commonly grown in Kansas. It will survive and persist with no 
supplemental nitrogen, but giving it one lb. N per 1,000 sq. ft. will 
improve color and density. This application should be made in early 
June. For a little darker color, fertilize it as described for 
zoysiagrass in the previous paragraph, but do not apply more than a 
total of 2 lb. N per 1,000 sq. ft. in one season.  As with zoysia, 
slow-release nitrogen is preferable, but fast-release is also OK. As for 
all turfgrasses, phosphorus and potassium are best applied according to 
soil test results because many soils already have adequate amounts of 
these nutrients for turfgrass growth. If you need to apply phosphorus or 
potassium, it is best to core aerate beforehand to ensure the nutrients 
reach the roots.

Alicia Boor is an Agriculture and Natural Resources agent in the Cottonwood District (which includes Barton and Ellis counties) for K-State Research and Extension. You can contact her by e-mail at [email protected] or calling 620-793-1910.