Over the years, I have defined a difference between a “fall” lawn fertilizer and a “wintering” fertilizer. These two types of fertilizers really address the root growth and winter hardiness of Kentucky Bluegrass.
Physiologically, grass produces an excessive amount of new roots in the spring and also in the fall when temperatures are cool, soil moisture is high, and primary nutrients for root development are readily available.
Kentucky bluegrass roots develop from underground nodes of rhizomes and from basal nodes of aboveground shoots called the crown. The roots also develop in the terminal nodes of the rhizomes that emerge above the ground as shoots.
Root growth is greatest in the fall, followed by the spring period and slows to almost a halt during the high temperatures of summer. Kentucky bluegrass root growth peaks at soil temperatures of 60F and declines sharply as temperatures exceed 70F. Root growth virtually ceases at temperatures above 80F.
FALL fertilizer should be applied when the soil temperature begins to reach 70 degrees until the soil temperature reaches the 55 degree mark. A true fall fertilizer is designed to build new roots for turfgrass plants by providing additional phosphorus (P) and potassium (K), which are the primary nutrients needed to grow healthy new roots. This dose of “P&K” stimulates and supports new root growth, so your lawn can “dig in” and prepare for cold weather. The fall fertilizer also prepares the root of your lawn to use 100% Winterizer fertilizer, which should follow 4-5 weeks after the fall fertilizer application.
Accumulating and storing carbohydrates in these newly formed roots is the name of the game when it comes to the next stage of nutrients to be applied.
WINTERIZER fertilizer, on the other hand, is a fertilizer meant to be applied after the grass plant has created all those new, EMPTY roots and just before the ground freezes solid (or in the case of cheap skids, a of the two fertilizer applications). offer their lawn every year). It is also possible that this fertilizer is triggered by early season, wet snowstorms or rains that always come a few weeks before the first sticking snows. So, in other words, don’t worry about keeping your sprinkler system running until December just to water or activate your winter conditioner application.
The role of this HIGH NITROGEN application (1.5 – 2 pounds of active nitrogen per 1000 sq. ft.) is to supply the maximum amount of nitrogen that can then be converted into usable, stored carbohydrates before the soil freezes. This application helps feed the plant through the winter in southern areas or prepares cool-season pastures for the longer winter ahead. Another benefit of this application is the EARLY greening of your lawn or your clients’ lawn next spring.
To summarize, carbohydrate accumulation in rhizomes peaks in late fall when “above ground” or shoot growth of Kentucky bluegrass slows. As temperatures become favorable for growth in the spring, these carbohydrate reserves become available for new shoot development again.
In essence, this app will “collect your lawn in bed” and keep it safe through the long, harsh winter, allowing you to emerge in the spring as the Champion all your neighbors will envy. green of envy!