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When is It Best to Fertilize Cool Season Grass? (2023)

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In the components of the nation with cool or cold winters, yard care routines could possibly not be probable or necessary all through people months. For cool season grasses that will endure people cooler temperatures, upkeep will truly feel like planning for and recovery from winter.

Like numerous plants, the time period of most energetic development is spring and fall. Interesting season grass goes dormant in the summertime and winter, so your fertilization routine for people grasses will be centered inside of the transitional months.

Interesting Season Grasses

Interesting season grasses develop in spring and fall and go dormant in winter and summertime. These contain Tall Fescue, Kentucky Bluegrass, and Perennial Ryegrass, which sprout and thrive when temperatures are in the 60s and 70s.

These grasses develop hearty blades that are superior ready to stand the cold winter months, whereas they can not tolerate the heat of summertime.

Testing Your Soil Profile

Prior to fertilizing your soil, you should really execute a soil check to see which nutrients it might require extra or significantly less of. Some men and women check their soil as soon as a 12 months, in spring or fall, to keep away from taking corrective techniques quite a few many years apart.

In some parts of the nation, soils might be naturally minimal in 1 or a further mineral. When grass grows, it requires nutrients from the earth to develop its construction, so more than time, you have to supplement these in the soil for a nutritious lawn.

A lot more than most likely, if you are following your routine, fertilizing to give your lawn a frequent improve of nutrients will retain it in regular stability. On the other hand, if it has been a particularly moist 12 months with flooding and/or large development, your soil might be extra depleted than typical.

Soil Fertility

Soil Fertility

Executing a DIY soil check, or acquiring it accomplished by a nearby university extension workplace, will enable you to know about the situations of the rising surroundings for your lawn. These exams check out the pH degree (which measures acidity) and the primary elemental minerals accessible in the soil (listed on grass fertilizer formulas as N-P-K: nitrogen, phosphorus, and potassium).

The pH degree measures the acidity of the soil. PH stands for “potential for Hydrogen,” the place the extra Hydrogen ions existing implies increased acidity and a decrease degree of biotic action. Alkalizing minerals like lime and potash might require to be extra to make the soil extra hospitable when the soil is as well acidic.

Phosphorus in the soil contributes to fantastic root development, whilst potassium assists the plant’s cellular construction retain water.

For mature grass with powerful root methods, nitrogen is the favored nutrient, a basic element of chlorophyll, which can make the grass green, and the photosynthesis procedure can make the sugar that offers the grass vitality to develop.

How Frequently Should really You Fertilize Interesting Season Grass?

Interesting season grass should really be fertilized 3 occasions a 12 months:

  • In early spring, when new grass is rising
  • In late spring, for summertime dormancy
  • In early fall, for winter dormancy, ahead of the ground starts to frost and freeze

Your Interesting Season Grass Servicing Calendar

Healthy Lawn

Holding a yearly routine will enable you to be certain to retain lush turf in each and every season. Not only will this enable you retain in tune with the seasonal adjustments and development patterns of the grass, trying to keep track of the high quality affliction of the lawn will enable you to know what to appear out for, what’s regular for your yard, and when the final time was that you carried out 1 or a further activity, as properly as how it went.

Due to the fact yard care is about development and managing development, fertilization is just 1 of quite a few routines needed to retain your lawn in exceptional-seeking affliction. Care routines like soil planning and mowing require to be accomplished in coordination with fertilization, planting, weed killer application, and watering.

In nature, timing is anything, so you want to retain on routine for the best benefits.

Soil Aeration

Minimal-tilling and lawn aeration are strategies to retain your topsoil in major high quality. Soil will get compacted more than time, reducing its potential to hold air and water and leaving significantly less room for roots to develop.

Soil aeration is best in the fall when new grass developments can set up itself ahead of a winter of dormancy to be prepared for its spring revival.

Planting Seeds

Planting seeds for cool season grasses is best accomplished in early fall and early spring, providing quite a few weeks for the grass to set up itself ahead of dormancy in the scorching and cold months. Overseeding or planting seeds to fill in a presently grown yard, is best accomplished in the fall just after aerating the lawn.

This offers the new grass a season of rest concerning its new root development and the approaching spring season of blade development.


As stated over, cool – season grasses should really be fertilized in the spring and fall. To get the greenest lawn with the densest coverage for any lawn’s distinct traits, fertilizers come in numerous diverse types and interact with the grass in diverse strategies.

Synthetic fertilizers are guy-produced nutrient isolates, that means they are the pure kind of the component. These are element of a fertilizer formula that presents promptly available nutrients for instant use by the plant. These should really be utilized in the spring and fall mainly because they are straight, accessible to rising roots and grass.

Natural fertilizers are formulas that use normal substances like manure, compost, and other animal or vegetable products. Due to the fact these require time to be broken down by the soil’s biotic action to be accessible, they should really be utilized in the summertime. The nutrients will be gradually launched more than the following 12 months.

When Should really Nitrogen Fertilizer Be Utilized To Interesting Season Lawns?

Nitrogen Fertilizer

Nitrogen should really be extra in the fall considering the fact that development in the summertime of warm- season grasses will use up a good deal of the soil’s nitrogen for their blades and to retain them green. In fall, fertilizing with nitrogen will supply the cool season grass with a fresh provide of nutrients to develop its blades and put together for the winter dormancy.

Nitrogen-wealthy fertilizers might also be regarded as “grass food” considering the fact that they emphasis on blade health and fitness and look.

What About Phosphorus And Potassium?

Potassium will be incorporated with numerous diverse fertilizers considering the fact that it contributes to cell-wall power and moisture retention. Applying phosphorus outdoors of germination intervals, on the other hand, can block plants from absorbing nitrogen. It is utilized largely in starter fertilizers considering the fact that it is important for root growth.

Weed Prevention

Your fertilization plan will retain your lawn green and rising, so trying to keep the development of undesired plants beneath handle is as essential to the health and fitness of the lawn as giving it with nutrients. One particular of the initially techniques of the spring or fall season, even ahead of fertilizing, is to attend to any weeds you see.

Be on the lookout in early spring and late summertime/early fall, when weeds might pop up. If you do not catch the weeds ahead of you fertilize, you might inspire development of people and your grass.

Making use of a pre-emergent herbicide will target weed roots whilst not disturbing your grass’ root method. A publish-emergent herbicide targets the leaves and stalks of weeds, killing its root method for lack of photosynthesis. It is proposed to wait about a week just after herbicide application to place down fertilizer.


Mowing ahead of placing down fertilizer can enable the merchandise attain the soil superior. After utilized, fertilizer desires a day or two to soak into the ground. Immediately after laying down the fertilizer, watering the grass will enable the filth and the roots soak up it. Get the soil moist and wait a couple of days ahead of applying fertilizer.

Raking For Thatch And Lawn Buildup

Thatch And Lawn Buildup

Like with mowing, clearing the soil’s surface ahead of placing down fertilizer will enable it to be absorbed by the ground superior. Publish-mow is also a fantastic time to rake for thatch: the buildup of dry, dead grass and other yard litter.

Fertilizer can get caught in dense thatch, which also blocks sunlight from reaching the base of the grass’ blades, suppressing the development you are striving to inspire.


Interesting season grasses have a tendency to demand extra water than warm- season grass, which is superior adapted to dry situations. Tall Fescue has deep roots and is extra tolerant of drier soil, but  Kentucky Bluegrass and Perennial Ryegrass will go dormant all through a drought.

Interesting season grasses are utilized to the precipitation of spring and fall, so if there is significantly less rain than typical, retain an eye on the soil moisture degree and supply further water as needed.

Should really I Fertilize Interesting Season Grass In The Summertime?

Interesting season grass does not require to be fertilized in the summertime considering the fact that it is not a time period of development for that grass form. Minor further nitrogen from your summertime fertilizing could possibly not harm, but as well a lot phosphorus or potassium might be absorbed by the cool season grass’ roots, which are in a vitality-conserving state and tension the dormant plant.

Warm season grasses share their development time period with cool season ones in spring, but whilst cool season grass goes dormant, warm season grasses like Bermuda or Zoysia will thrive all through summertime. Warm- season grass fertilization in the summertime is frequently largely nitrogen for blade shade and density.

Interesting season grass roots might be stressed all through scorching dry soil situations and can advantage from a minor of the nitrogen fertilizer that the energetic warm season grass will mainly soak up.

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Mutasim Sweileh

Mutasim is a published author and software engineer and agriculture expert from the US. To date, he has helped thousands of people make their yards lush and thick.