Summer Lawn Fertilization

Lush Summer Lawn

It is tempting to do a light mid-summer lawn fertilization, because it sometimes produces a rapid rich luscious green lawn growth. Sometimes, on the other hand, it thins lawn growth or even turns the grass brown (fertillizer burn). Scotts makes a mid-summer fertilizer mix (light on nitrogen) and claims it won't burn the grass. In the fine print, though, Scott's warns homeowners not to use the mix if the temperatures will be rising above 90 degrees. Other fertilizers which claim their supplement is specially adapted for summer are "Seed Starter" - the numbers are 10-10-10, and "Turf tone" by Espoma, which has almost the same formula. 

But what is the truth about summer fertilizing? First off, summer grass is not actively growing. What, you are thinking, my grass grows and I mow the lawn every summer. Yes, but active grass growth means the tiny plants are storing food in the roots, growing and developing the root system, forming rhizomes, and tillering (producing new shoots).  During the hot stressful summer, the blades grow, but the plant is, if anything, utilizing and not storing root food. And it is best to give grass fertilizer when the grass in the active growth mode. Fertilizing in the summer causes unnatural rapid shoot growth. Underground the roots become flimsy and succulent, unable to penetrate deep into the soil like healthy roots. So even if the above ground grass growth looks vital and green, underground you are damaging the plant. Over time you will compromise the plant's health, making it vulnerable to stress, and impairing its growth. 

Fertilizing with an organic supplement is a healthy alternative to summer fertilization. Organic mixes such as Milorganite, soy bean meal, and others feed soil organisms and not the roots. Soil organisms contribute to healthy grass growth and also slowly metabolize the supplement, turning it into nitrogen that will be available for the grass growing seasons. Synthetic fertilizers, on the other hand, (Scott's et al) feed the grass and cause the unnatural harmful growth alluded to above. So this summer or the next, if you must fertilize mid-summer, choose a healthy organic supplement instead of a synthetic fertilizer.

For expert lawn care in the Westchester and Putnam County areas, contract the Turf Barbers. 929 Quinlan St, Yorktown Heights, NY 10598, United States; +1 914-302-2469; http://www.trufbarbers.com