Fall is the best time to ready your field for winter conditions.
In many regions of the U.S., homeowners see fall as the big countdown to a time they can put away their mowers for the year. Sports field owners and managers, however, know they have a ways to go before they can lock the gate on the facility. Football, among other sports, will make sure of that. It’s always a challenge to maintain healthy turfgrass as late as possible into the growing season – and it gets even worse in areas where frost hits early.
Here are a few techniques field managers can use:
Overseeding: Often with perennial rye or transitional rye, overseeding is a common practice for maintaining winter color and cover for warm-season grasses and for increasing the turf density on cool-season grasses. Ryegrasses germinate and establish themselves quickly; newer varieties are drought- and cold-tolerant, as well as durable.
Irrigation: Of course, irrigation has to continue, and will become increasingly important as the field becomes more vulnerable and less able to repair itself through growth. To help water infiltrate, make sure the turf is aerated to break up compaction.
Fighting the slowdown: Cooler temperatures will slow the growth of grass. That’s an indisputable fact. The options for combating this fact can be limited by budget, as well as by the level of competition on the field. Some field managers, in cases of very high-performance fields, actually work to install heating systems within the rootzones of their fields. These systems consist of plastic tubing laid in loops on 6- to 9-inch centers. They are installed in pea gravel 10-12 inches below the field surface. In most cases, the loops run end-to-end over the entire field, although on occasion they may run side-to-side. The system moves heated glycol through the tubing, radiating into the rootzone above.
It’s a great idea, but, for the manager charged with keeping a municipal or high school field in playable condition, it might not be feasible. Therefore, a variety of options exist for those with more modest budgets. The ever-popular practice of tarping the field at night often comes into play. A vented plastic tarp used overnight can raise the soil temperature enough to prevent freezing; however, remember that raising the heat and humidity level of the field can promote disease.
Until the soil temperature drops below 50 degrees, micronutrients and/or chelated iron may help the turf maintain its green color without spurring growth. But once temperatures drop to a point where encouraging turf growth is no longer practical, the use of field colorants will temporarily improve the appearance, but not the performance, of a late-season field.
Winterizing Your Irrigation System
Since you wouldn’t go through a freeze/thaw cycle with the hose bibs at your house turned on, extend the same logic to a field system. Particularly if the field is in an area of hard freeze, take all precautions to keep the irrigation system safe for the following system:
- Check each of the system components. Look for areas of weakness, loose connections, cracks, leaks or any other problems, and take the time to repair or replace those. Spring seems a long way off, but you won’t want to deal with non-working fixtures with spring sports breathing down your neck.
- Drain the system using installed drains or a high-volume, low-pressure compressor or both. Only a knowledgeable person should attempt blowing out an irrigation system, because, if done incorrectly, this process can be dangerous.
- In some areas where cold temperatures and bitter winds desiccate the turf, it may be necessary to recharge the system, irrigate and re-winterize it in order to maintain field quality.
Winterizing the field
Fall is the best time to prepare the field for use in the spring. Good preparation can both help to protect the fields from winter damage and make the fields available for use earlier in the spring. Unfortunately, winterizing practices also optimally occur during fall season sports.
Therefore, developing a program for pre-winter activity will depend largely upon the availability of the field – and the date activity on it stops altogether:
For cool-season grasses, early fall fertilization allows the grass plants to store carbohydrates to tide them over winter and spur new growth in the spring. Except in the North and Deep South, August, September and October are the recommended times for final fertilization. In the North, fall preparation may begin earlier.
For warm-season grasses, time the last fertilization before the first frost. The goal is to apply fertilizer once the grass shoots have slowed or stopped growing but while the soil is still warm enough and the roots active enough to take in the nutrients.
If the field has become overly acidic during the playing season, fall is the time to adjust the pH by the addition of lime. A soil test will be necessary to determine the rate of treatment.
By the late fall, the fields may be worn between the hash marks for football fields or around the goals for soccer fields and can look quite bare. However, well-maintained fields with strong soil and healthy root growth will still play well. Fall is the time to do the work to ensure the rootzone and grass will be ready for the spring season.
The fields will have become compacted through use during the season. Healthy grass will continue to grow, but to survive and thrive over winter it will need more air in the soil. If it does not disrupt fall play, core aeration is recommended. Alternatively, a slice aerator will accomplish the same task with less disruption. If a slice aerator is used to minimize disruption to programming, once the season is over, the field should be cored and the cores dragged back in with a drag mat or a piece of chain link.
Next, if possible, the field should be de-thatched. Depending on the amount of thatch, the field should be dethatched in four to 10 passes and may generate tons of material. After dethatching, the field may look very sparse.
Many sports field managers then trench the perimeter of the field to cut down on grass migration over the winter.
As mentioned previously, overseeding with perennial rye will provide winter color and help protect the bermudagrass from wear over winter. Treat stress areas with additional seed. In cool-season areas, dormant seeding of the normal turfgrass variety should follow dethatching. The success of dormant seeding will depend on good soil contact and preventing the seed from washing away during winter. Overseeding just prior to a practice or game allows players to cleat in the seed, ensuring good contact. Topdress after seeding if the budget permits.
Consider the use of a growth blanket to encourage germination, in warm-season areas for winter cover and in cool-season areas for earlier growth in the spring. Do a regular check under the blankets to ensure no mold or disease develops. (Alternately, a protective cover of weed-free straw or other material may be applied.) Finally, irrigate the field to set the seed and leave it resting for germination once soil temperatures are consistently above 50 degrees.
Each of these recommendations and precautions should be documented carefully. If, upon re-opening the fields in the spring, a field manager sees unexpected success (or conversely, a lack of success in one area), it is helpful to have thorough records that will help him or her identify what worked and what didn’t – in order to know what to do the following year. At the end of the day, a good journal of seasonal work is the most valuable weapon in the field manager’s arsenal against the ravages of heavy use and inclement weather.
Editor’s Note: The American Sports Builders Association has excerpted some of this information in its publication, “Sports Fields: A Construction and Maintenance Manual.” For information on this publication, visit www.SportsBuilders.org.