With so many potential benefits from baseball field covers, many field managers wonder just how long and how often they can apply the cover without damaging the turf. While applying a cover to the skinned part of a baseball field will rarely cause damage to the turf, it’s a different story when there’s overlap or the turf is intentionally covered for frost protection. Leaving a cover on too long risks serious damage to the grass roots, while taking the cover off too early is inefficient and wastes some of the benefits. Find out how to put field covers to optimal use without risking damage when the stakes are high.
Application and Removal
The key to efficient use of covers, over turf, is to stay prepared to apply and remove the tarp as needed. Turf should never stay covered for more than a few hours when temperatures are above 60 degrees F. Even if the forecast calls for constant rain, a sudden change to sunny conditions quickly heats up the cover and roasts the grass below. If you must leave a cover on for an undetermined amount of time, stay near the field and be prepared to remove the material as needed within 30 minutes of a change in weather. Since most field covers require a whole group to coordinate, don’t apply any covers over turf on warm days when there’s no one readily available and in the area.
Material Selection
Using a mesh or permeable tarp gives you more leeway when attempting to speed up germination and encourage strong root establishment. Since mesh tarps allow air to circulate, less heat builds up. However, they’re also prone to speeding up growth so fast that it rapidly becomes crimped by the weight and height of the cover. Make sure you’re still planning to remove mesh tarps after only 1 to 3 days of use to avoid the loss of grass that grows through the material. You don’t want to damage all the new seedlings and their delicate roots by pulling away the intertwined cover and yanking all the grass along with it.
The Greenhouse Effect
All baseball field covers risk some amount of greenhouse effect because they insulate the ground and trap heat. The amount of the effect depends on the ambient air temperature outside. At below 60 degrees F, it’s generally safe to leave a tarp on for up to 96 hours before the cumulative greenhouse effect gets too strong and risks damage to the grass. When temperatures are at 60 degrees F, limit tarp use to 36 hours or less. Anything above 75 degrees F should limit your use of covers to just a few hours at the most, especially when there’s a chance of direct sunlight falling on the cover. Using white and reflective materials will help but can’t entirely counteract the greenhouse effect.
Water Pooling and Weight
Don’t let water stand on the surface of a field cover just because it’s not soaking into the soil below. When covers are spread out over turf in particular, the accumulating weight adds up quickly enough to crimp and crush the blades below. You may notice smothered or brown spots anywhere large puddles accumulated while a cover was used for more than a few hours. This is because the combination of heat and weight can damage grass faster than either problem alone. Clear water off of tarps regularly when there’s a big storm, even on skinned areas, to ensure there are no compaction issues to deal with after the rain is gone.
Fungal Growth
Turf grasses come from dry open prairie habitats, so they don’t do well when kept damp by an insulating cover. Fungal diseases are particularly prone to moving in when there’s regular use of a cover over turf in warm weather. Even in cool weather, diseases like pink snow mold can develop to damage the grass while it’s out of sight. Spraying the fungicides appropriate to your area can help prevent this, especially during longer or warmer periods of cover use. Fertilizers high in phosphorous can also help prevent the problem without requiring carefully timed chemical applications.
After having a cover on the turf for a few hours or even a day, make sure to leave the grass exposed for as long as possible before covering it again. Grass is shocked each time it’s deprived of light for more than a short time, even when it would naturally be dark due to cover use overnight. Giving the turf plenty of sun before it’s used again is the best choice. Make your athletic field covers easier to remove in a hurry by using flexible and lightweight RPE from us here at BTL Liners.
