Recovery Tips for Damaged Greens - Archived
Archived from 2015 for Reference
By John Garcia, Chris Cowan, and Scott Mackintosh M.S., CPAg
Mother Nature strikes again! Unfortunately there are an increasing number of calls and reports coming in of winterkill on putting greens throughout New England. Although there are certainly some concerns with ice encasement damage (anoxia), there are several others that never experienced any significant ice, but still have damage. Those folks are saying that they had 1-2” of white, porous ice for 4-6 weeks, and as it has been removed and/or melted down, it has exposed “super saturated” , black looking turf predominately on the poor draining pocketed areas on their greens. There have been lots of papers and reports written on the physiological and environmental reasons behind winterkill, and even some decent broad-stroked ideas on dealing with the aftermath/recovery. At this point however, it does not matter how or why, or if something different could have been done to avoid it. What matters is returning surfaces to playable conditions. This short article is focused on specific thoughts, ideas, and methods to get your greens back as quickly as possible.
Cool season grasses such as poa annua and creeping bentgrass begin to germinate at soil temperatures at 50 – 55F. In fact, the optimum temperature for cool season shoot growth is 59 - 75F and maximum root growth and tillering for cool season grasses usually occurs between 59 - 68 F. Maximum photosynthesis ranges from 68- 78F with a maximum of 87F (1). So, if you are dealing with damage, the #1 mission is to get your soil temps up to facilitate recovery. This can be expedited in a number of ways:
1) Aerate with 3/8 or ½ inch solid tines on the tightest spacing possible. No need to go deep, ¾”-1” is enough. The goal is to open the surface allowing the warmer spring air and sunshine to get into the primary root zone/seedbed.
2) If possible use covers at night and on cold days to maintain the temperature gains made during the day. The Evergreen covers with the green weave work great! Borrow covers from a neighbor if you don’t have them/can’t afford them. Enka Mats are also a valuable tool for raising soil temps and aiding in germination.
3) If possible, spray pigmented products like TurfScreen Pure Pigment at the highest recommended label rate. The dark color will help to capture the warmth of the sun and raise surface temperatures faster.
4) Be sure to monitor soil temperatures in the rootzone and pay close attention for the potential of fungal pathogens. Granular Fungicide IX is a great product to use in these situations.
5) Soil moisture can also impact soil temperature in the spring. While its important to maintain adequate moisture
for germination too much water can insulate the soil and slow the increase in soil temperature (4).
You may need to roll greens prior to the initial aeration, as some greens tend to soften up over the winter. The last
thing you want to do is rut up the surfaces while trying to repair them. Avoid pulling cores and at least initially, the urge
to topdress. Although things may look bleak, there may be more viable plants in your surfaces than you think. Dr Michelle Dacosta, of The University of Massachusetts mentioned at a recent Seminar that although a plant may shoot out green leaves, it’s the bottom of the crown that is the most vulnerable. If you are too abrasive with the surfaces through removing cores, or dragging sand, you may be doing more harm than good. Keep aeration practices solid, shallow, and on the tightest spacing possible. The goal is to warm the soils and provide a seedbed conducive to growth and recovery. Soil amending and thatch reduction must wait!
Although bentgrass won’t germinate until soil temps are in the 50’s, there is no reason to wait getting it out there. Seed the weak areas early and often. When choosing varieties remember, bentgrass is a species. There are no cultivars that will germinate faster than another…..regardless of what someone’s marketing piece might say. There are however, statistical differences in post-germination establishment rate, spring greenup, and cold hardiness…..so, utilize the NTEPs and choose varieties that make the most sense for your situation. Consider coated seed! Seed coated in a water- retaining polymer (like Barenbrug’s Yellow Jacket), will give you the best chance of quick establishment. You may not have your irrigation system charged early enough, and even if you do, the coating will help to provide you an insurance policy during the critical establishment period. Extensive University research shows more than a 10% improvement of germination and establishment with coated seed vs. uncoated.
In dealing with cold weather/soil grow-in situations, it’s important to recognize that you are dealing with a compromised or juvenile root system, and chemical reactions that cannot take place quickly. In fact, the minimum soil temperature of
50 - 55F is considered necessary for sufficient mineralization activity to enhance release of N for plant use from organic
nitrogen carriers. As soil temperature increases from 32 - 41F a very gradual increase in nitrification occurs (2). Therefore, apply liquid/soluble fertilizer in early April if you need to feed. Try and wait until the soil temperature begins to climb to the upper 40”s before making a granular fertilizer application. Making a granular application in cooler soil temperatures will not by utilized efficiently by the soil microbes or turfgrass plants. The two most effective cold weather Nitrogen sources are Ammonium Sulfate, and Calcium Nitrate. We recommend utilizing Ca Nitrate as it can be applied
as a granular or sprayable product, providing application flexibility. It is a 15.5-0-0 with 19% Ca. Calcium is a vital
constituent of cell wall division, and root hair growth, and therefore is the better option for this situation. Light, frequent applications are far more beneficial than large amounts in a single application. In fact, quick release N applied over ¾ lb may “shock” the plants, cause weak/succulent leaf tissue, and be lost due to runoff/leaching. Once germination has begun, fertilize with .1-.2 lbs/1,000/N per week for the first 2-3 weeks. If you are spraying, consider a fulvic or amino acid additive such as KaPre Exalt, Embella, or Pennemin Perfect to help free up bound micro-nutrients and allow the seedling access to the nutrients they need.
Once you are happy with the percent germination, supply a balanced, N-P-K granular fertilizer such as Ocean Organics SeaBlend Super Starter 5-7-5 at a rate of .75-1lb/N/1,000. IBDU is also a fantastic N source for early establishment in the spring. Several studies have shown better establishment with IBDU than with urea or Ureaform (1). Avoid the temptation to make multiple, “high-dose” granular applications with slow release Nitrogen sources, as you may lose control once temperatures warm up. We have seen this situation in the past, and it becomes very difficult to improve green speed once you lose control over the N release!
Clearly, the longer that traffic (from equipment and golfers) can be delayed, the better and faster the recovery will be. Members and golfers will certainly want to be out there as the temperatures rise, but tempering expectations through frequent communication and education will help everyone in the long run. A few temporary greens in April and May is a small price to pay for outstanding conditions the rest of the season. Last spring we witnessed the best recoveries in our region when greens were shut down until late May. Closing to golfer traffic also takes pressure off of the
Superintendent that might feel the need to mow or roll more often when the green is open. Golfers have short
memories and will thank you in June/July if caution is used early……A closed putting green WILL RECOVER QUICKER if traffic is reduced!!
We are here for you
Atlantic Golf & Turf’s team of Professionals has the experience, the knowledge, and the resources to help you make the best decisions possible as you work through this very difficult situation. We understand that each situation is unique, and we will always have your best interest in mind when making agronomic recommendations. Good luck, and HAPPY SPRING!
List of References
1. Beard, J.B. 1973.Turfgrass: Science and Culture. Prentice-Hall, Englewood Cliffs, NJ.
2. Carrow, Robert N. D.V. Paddington, P.E.Rieke. 2001. Turfgrass Soil Fertility and Chemical Problems: Assessment and
Management. John Wiley & Sons Inc., Hoboken, NJ.
3. Mazur, A.R., and C.B.WHite. 1983. Mineralization of N from several sources and establishment of ‘Penncross’ creeping
bentgrass on putting green media. Agron. J. 75:977-982.
4. Tisdale, S.L., W.L. Nelson, J.D. Beaton. 1985. Soil Fertility and Fertilizers. Macmillian Publishing Company, 866 Third
Avenue, New York, NY.