Ross Kurcab is a Certified Sports Field Manager (CSFM) and a professional sports field consultant with 30 years’ experience
as a head turf manager in professional football. He graduated from Colorado State University’s Turfgrass Management program
and now operates and owns Championship Sports Turf Systems.

VENTED TURF BLANKETS

Vented turf blankets go by different names in the industry, “growth covers” is perhaps the most common. Whatever we call them, they can be a most valuable tool for any sports field manager trying to improve the performance and extend the playing season of their natural grass playing surfaces.

Turf grow tarps can be made in almost any shape and size by the better manufacturers. They serve a variety of purposes for the turfgrass and sports field manager, but all stem from warming the soil and grass canopy using sunlight and minimizing radiation heat loss at night. They are used by field managers to warm all or part of the playing surface in an effort to extend growing seasons for natural grass surfaces. They are also used to enhance seed germination and grass growth and development when normal climatic conditions would otherwise keep or put the turfgrass into a slowed state or dormancy. They are made of a lightweight, high-tech woven plastic material that can be installed with as little as 1-4 people in light wind conditions (depending on size of the cover) and 2-8 people in higher winds (10-15 MPH), in my experiences. See my blog on installing field covers in reasonable winds.

The result is a simple, easy tool for field managers to see sometimes dramatic results with proper use. Even if your current budget has little room this year, try getting a small vented turf blanket that covers a critical, high-use area of your field, one soccer goal mouth for example. When the field stakeholders and decision-makers see the results, you will stand a better chance to fund more or larger covers as you may need.

First up, how does a vented turf cover work? The same reason your car heats up when you leave the windows up in the sun.

First, a vented grow cover allows sunlight to pass through (translucence) to the surface. The surface (soil and grass in our example) is warmed by the sun, re-radiating longer wave infrared heat. Much of these heat waves are reflected by the cover material back down to the surface. In this way, the grow tarp traps and builds heat energy underneath the cover. The result is the turfgrass growing in temperatures up to 35 °F higher in certain situations than conditions outside the cover, in my experiences.

Second, the turf blanket can trap and hold heat from escaping at night due to this shortwave-longwave “greenhouse effect”. Especially on cloudless, clear nights when temperatures can plummet, vented turf covers can hold in some of the trapped heat overnight. This may also help to minimize the potential for direct low temperature injury (DLTI) to the turfgrass.

Third, a seed germination blanket can minimize the chances of cool and cold season desiccation (drying out) of the turf and hold moisture in the seedbed for seeding and overseeding.

The vented design allows for gaseous exchange, getting needed oxygen to the turf and releasing built up CO2 from respiration. The woven design also allows some heat out to minimize potential for high temperature stresses on the grass and even some injury in extreme cases. As such, vented turf blankets are not designed to be used in the hot months. Always monitor temperatures and conditions under your cover frequently. Temps can build up fairly rapidly in certain conditions.

Day length will affect the amount of warming, and the higher sun angles of spring and fall will intensify the heating compared to the lower sun angles of winter.

“Cheap is not less expensive” applies well to growth blankets. There is a lot of technology in the higher quality vented turf blankets that you don’t really notice, but these technologies make a huge difference in performance.

The quality of the material used to make the grow blankets for turf is key. Woven polyethylene fabrics are not a highly durable product. They may break down quickly from UV radiation in sunlight, especially in certain climates. The woven construction can come apart. Tears can keep going.

Covermaster has solved this issue with their patented lace coating which not only adds tremendous strength to the woven cover, it also allows the edges of the cover to remain free of sewn seams and grommets. The edges don’t fray and you can pin the covers down as tightly as needed, placing the powder-coated pink pins wherever you need them, even out in the middle of the cover to baffle wind waves. You can’t do that with cheaper turf blankets, they may just start fraying and tearing. This strength-giving patented technology allows for a slightly looser weave, allowing for better gaseous exchange. If you happen to get a tear in the cover, it will not advance with this technology. Another huge advantage of this technology is that it will allow you cut and fit your vented turf blanket to the specific shape of your field or area. Try that with the cheaper vented covers-it can’t be done.

Higher quality turf covers are also treated with a UV-resistant protectant to extend the life of the fabric of the covers. All this adds up to not only better performance but also an extended life-span of your cover. All said, you are better off in terms of cost/use over the years by far when you purchase a high-quality vented turf blanket than going for the cheap imitation covers in my opinion.

See more about Covermaster Evergreen Turf Blankets here.

Turf Tips 101: Tips on Using Vented Turf Blankets

Vented turf growth blankets are a versatile turf management tool and can be used to achieve a variety of objectives. A few simple tips on their use and maintenance:

Make sure it is safe to push 6-inch pink anchor pins into your surface without hitting dangerous or damageable field components or underground elements.

Storage, deployment and uncovering. From my experiences, it’s worth storing your vented turf blankets indoors to limit UV degradation and other forms of weathering. How you fold and store your cover(s) depends on your storage capacity and the size of the cover(s). Small covers can simply be unpinned and folded up by hand like a bed sheet. Large pieces, like part of a full-field turf blanket system, can still be folded, but the size and weight will require more people. I have used two different ways to do this.

Large area grow tarps are typically folded in successive halves to create a long, skinny run of folded covers. From here the cover can be rolled up onto a large diameter tarp drum or folded in successive halves lengthwise to create a square, folded cover on top of a solid-topped pallet.

For breezy conditions, you can leave one edge pinned down as you fold in half a couple of times to fit your needs. This can also be done during a breezy deployment of the turf covers.

Always walk the edges and any other area where pink anchor pins were used during deployment to make certain none are left in the field.

In the mornings, grow covers can sometimes be wet and heavier from condensation under the cover under certain conditions. The covers dry quickly with a little sun or wind, making them lighter to handle.

Or, if you want to mechanize the process and gain several other advantages, you might consider the MacLeod Field Cover. It works to stimulate growth the same way as Evergreen Turf Blankets with several added benefits and capabilities. You can read my blog from last year about the MacLeod Cover here. Watch a YouTube video about the MacLeod Field Cover here.

It’s not a good idea to anchor the corners or edges of your vented turf cover with heavy equipment to hold against the wind. The anchor pins are designed to hold the cover securely, but if high winds hit, they are designed to release before tearing the cover.

Monitor and check turf often.

Be sure to secure any field irrigation system before you deploy your field covers. You don’t want irrigation zones and heads popping up and washing out under the cover. You can however irrigate over the top off the cover with hoses and/or water cannons as needed.

In terms of maintenance, there is hardly any. The covers tend to be “self-cleaning” whenever you get a good rain of irrigation over the top. If, with a lot of use, the edges of your Evergreen Turf Cover get a little beat up from constant pinning and unpinning, you can simply cut back an inch or so on the edges to get a clean start. You can’t do this with the less expensive imitations.

Resources of the Month: More Vented Turf Blanket Images.

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“Grass does not grow faster if you pull on it” -African proverb