Dormant Sodding

THE SCIENCE OF DORMANT SOD

In Southeast North Carolina all warm season grasses lose their color and go into a safe, dormant (sleeping) state. As fall approaches the incidence of sunlight (direction, angle, and intensity) decreases enough for plants to start slowing down their inner processes. This commences the beginning where grass blades go off color and eventually reach their true dormant colors of brown to gold depending upon your variety of turf grass.

This overall phase of dormancy begins when the soil temperature has declined to 67 degrees.

After several frosts in November your lawn is well headed into full dormancy. Root growth stops when the soil reaches 47 degrees.

For established lawns – where the grass is well knitted down and has been mowed at least five times, a Pre-emergent Herbicide needs to be applied in September or early October. This will stop all winter annuals from germinating – such as Annual Bluegrass. A product that does a good job is called, “HIGH YIELD TURF & ORNAMENTAL / WEED AND GRASS STOPPER.” This Contains the Herbicide “Dimension”. This Herbicide forms a barrier in the top 1/2” of your soil preventing all weed seeds from germinating.

Farmer Supply on Oleander Drive keeps a good supply of this Herbicide.

It is important to understand that this Herbicide must NOT be used on newly installed sod – whether the sod is active or dormant, This Herbicide will NOT allow the roots to penetrate this barrier and knit down.

A Post-Emergent Weed Control Herbicide can be used after the turf has been mowed five times.

  WHY INSTALL DORMANT SOD

  There are many advantages to installing dormant sod. There is no difference in dormant sods whether they are located in one of our fields or in your backyard. In fact, the micro-environment found in your back yard vs. an open field is much warmer and is less susceptible to desiccation due to cold drying winds.

By installing dormant sod in the middle of winter you will reduce the mud, dust, and weeds, control erosion, and still produce a finished appearance for that all important “curb appeal” or simply having an aesthetically pleasing lawn.

Installing dormant sod in the fall, winter or early spring, has another advantage in that you are not dealing with the high heat and humidity of June through August.

Did you know that frozen dormant sod can be installed on frozen soil and have no problems coming out of dormancy in the spring?

We annually ship many truckloads of dormant sod during late fall, winter and early spring with great success.

CARE INSTRUCTIONS FOR INSTALLING DORMANT SODS

Care must taken to assure that the dormant grass will live through the winter and break dormancy or “wake up” and begin growing, once again, in the late spring. The timing of this “waking up” period is dependent upon the same environmental factors that caused the dormancy to occur in the fall.

So we are looking for soil temperatures to rise above 47 degrees and exceed 67 degrees. Root activity wakens first.

Research has shown that several factors influences the success of dormant sod installation. These include:

1. Proper soil preparation, including the incorporation of a “Starter Fertilizer” (5:5:15) into the soil. Using a high Potassium (K) (0:0:32 or 0:0:60) is important as this Element strengthens the cellular walls of the growing region of each turf grass plant. This strengthening will allow for the expansion and contraction of this critical growing region during the fickle freezing and warming days during dormancy. If a “wall” tissue is cracked during an “expanding” freezing spell, than this one turf grass plant will not survive. This is rare.

2. Having a loose sod bed of 3/4” to 1” is preferred as the roots will than be protected by the soil acting as an insulator or blanket.

3. It is always a good idea to have good sod roots to soil contact. Rolling or tamping is helpful to insure that this condition is created. This will reduce voids and air spaces which can allow roots (dormant or otherwise) to dry out.

4. Proper water management is key!  DORMANT SOD NEEDS WATER TOO!!  A common misconception is that because the turf grass is brown, it does not need water. This is NOT true!

But because of more frequent winter time rains, and the evaporation and transpiration rate is greatly reduced during the dormancy period, supplemental irrigation is far less in the winter. But, one needs to know that cold, drying winds can cause winter time desiccation. It is important to keep an eye on a dormant lawn or on a newly installed dormant lawn that the roots remain moist.

 SPRING FOLLOW THROUGH PRACTICES

 1. Apply a pre-emergent herbicide (same product as used in the fall) to an established lawn that has been mowed at least five times. The time frame for this application is as early as mid February through mid March. This prevents spring and summer weeds.

2. When you see a new spring green understory, mow your lawn at your usual mowing height to clean up all winter debris and a portion of the tops of each dormant grass blade as they are pushed up from the growing region found at the soil level.

3. Fertilize after all chances of frost are over. This timing varies annually depending upon Mother Nature. Generally between April 15 to May 15th is a safe time to fertilize, and an efficient uptake of the nutrients by the roots will occur.

4. Continue mowing as needed and at the height as recommended for your turf grass variety.