Late-fall fertilizer application for cool-season grasses is best timed to occur which of the following?

• A. It should be applied just after the last mowing
• B. It should be applied before the last mowing
• C. It should be applied in mid-summer
• D. It should be applied in early spring

Answer: (A)

Fertilizing cool-season grasses late in the season is about giving the plants nutrients to store in the root zone for winter and to support quick spring green-up, rather than pushing a lot of new leaf growth. Applying right after the last mowing does this best: the grass has minimal leaf area, so the fertilizer isn’t wasted on extra top growth, and the nutrients can be taken up while soil temperatures are still favorable and stored where they’ll be most useful come dormancy and early spring growth. If you apply during mid-summer, the grass is already stressed by heat and the nutrients would mainly drive more growth now, which isn’t as beneficial. Applying in early spring tends to feed new shoots just as the season is starting, which can be less efficient for building root reserves before winter and may increase disease risk from new growth.