By Pamela Sherratt
What can you do when your turf is flooded after all the precipitation occurs?
Submerged turf needs to be uncovered quickly and renovated, since turf will die if it is submerged under water for several days. It’s important to get the water off asap and pumps can help to do this. Removing deposited silt and debris will be the next big task ahead. Brooms, rakes, vacuums and/or high pressure hoses can help to get the silt and debris off the turf. Tilling the silt into the top few inches of soil will cause all kinds of surface drainage problems in the future so the silt must be completely removed from site. Once the silt has been removed, evaluate the turf damage. If the field has been submerged more than a few days the grass will likely be dead so new turf establishment will be needed.
Silt and debris deposits do not typically cause problems with salts or heavy metals, especially in Ohio. Silt deposits can cause surface soil conditions low in phosphorus (P) and with a high/alkaline pH. A regular soil test will determine basic nutrient levels and recommend a fertilizer program for establishing new turf. The recommendations will focus on the use of phosphorus (P), since it is needed for turf establishment. In many areas there is a concern about using P, especially if it is a watershed. However, if the soil test determines that phosphorus is low, it should be used per the lab recommendation. There are some standard recommendations from states like Minnesota where they keep a close eye on phosphorus use and they advise applying 3lbs P during the establishment phase. Keep that paperwork on record in case anyone asks why P is being applied. This is important, since a fertilizer containing P must be applied or the turf will not grow in adequately before the season starts.
If planning a complete reestablishment, now would be a good time to look at field levels and see if it requires any earth-moving/leveling done. If budget allows (and it probably doesn’t right now) ask a local sports turf contractor to do some leveling and laser grading. If laser grading is not in the the budget then concentrate on surface cultivation to prepare a seed bed (coring, scarifying etc.), then seed it in early April as soon as soil temps are above 50 degrees. A good mix would be Kentucky bluegrass:perennial rye mix (80 blue:20 rye) at 4lbs/1,000 sq.ft. A high quality tall fescue blend would also be satisfactory, as they have really improved in quality and once established are tough as nails! Seeding rate for tall fescue would be 8lbs/1,000 sq.ft. and seed is much cheaper than bluegrass seed. Work with a local turf seed supplier to select a high quality “turf type” tall fescue blend that does not contain the Kentucky 31 common type.
An application of “Tenacity” (mesotrione) herbicide at the same time as seeding will prevent weeds like crabgrass from germinating without inhibiting grass germination. This is very important as April is a key time for crabgrass, nutsedge and knotweed to take over the bare soil. Keeping moisture on the field, especially in the first month while the seed is germinating, is critical. If there is no pop-up irrigation system someone needs to commit to get water on the field via a rain-train or hose & sprinkler head. The critical point here is to keep the new seedlings moist but not wet. Wet turf will not grow-in healthy and thick. Dry turf will not grow at all. The field will need micro-managing in the first 6-8 weeks – can someone do that? Lastly, consider sodding the field if budget allows. Sod gives an immediate green surface and it would be playable in 3 months if it’s taken care of (watered, fed, mowed and aerated).