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K-State Turf and Landscape Blog

Tag: injury

Testing for Winter Survival of Warm-Season Grasses

Posted on by Brooke Garcia

By Dr. Jack Fry

What a stretch of low temperatures we experienced in the state of Kansas from Februrary 6 to 19th! The lowest temperatures occurred on February 16th: Olathe, -18 F; Manhattan, -21 F; Wichita, -18 F. This makes those who are growing warm-season grasses concerned about how they’ll green up this spring. Snow cover is an important factor; more cover provides greater insulation from the extreme cold. Soil is a good insulator, too, which is one reason it’s a good idea to keep thatch to a minimum. When thatch accumulates, the growing points become elevated and are exposed to lower temperatures.

In our region, bermudagrass is the greatest concern, but freezing injury is also common on zoysiagrass. Areas that are most susceptible to freezing injury are those that experience shade during the growing season or are exposed to foot or cart traffic.

To look ahead and see if you might have winter injury, remove several plugs from each area that concerns you. Don’t just rely on a single plug – it doesn’t tell the story. Put them in pots and bring them in a greenhouse (if you have one) or on a windowsill within a warm room. Likewise, if you have grow lights you can put them under that will work, too. Warmer temperatures will encourage faster growth and evaluation. Give them 2 to 3 weeks under these conditions and look at how much green up you observe. Good green up makes us feel good about the approaching spring; lack of green up may require making plans for replanting.

Here are a couple of publications with related information:

 

A Hard Winter on Bermuda

Posted on by jahoyle

By Dr. Jack Fry and Mingying Xiang, (KSU Turfgrass Teaching, Research and Extension)

It was a hard winter for bermudagrass, and we saw extensive winter injury in Kansas – even to cultivars that we usually consider winter hardy. There is a trial at the Rocky Ford Turfgrass Research Center in Manhattan in which we’re evaluating experimental bermudagrasses from the breeding program at Oklahoma State University lead by Dr. Yanqi Wu (Fig. 1). Here are averages (of three replicated plots) of winter injury for standard cultivars included in the trial when we rated them on May 25: Tifway (100%); Latitude 36 (80%); Northbridge (75%); and Patriot (70%). The total loss of Tifway isn’t unusual, as it has poor cold hardiness. However, the severity of this winter caused severe damage to cultivars we previously thought were relatively hardy, including Latitude 36 and Northbridge. There is some good news. Several experimental grasses included in this trial experienced almost no winter injury, which bodes well for release of grasses with good cold hardiness in the future.

Fig. 1. Dr. Yanqi Qu and Mingying Xiang evaluate Oklahoma State’s experimental bermudas growing in 5 by 5 ft plots at Rocky Ford on May 25. Notice that many have extensive winter injury, while others are showing good recovery.

We heard from turf professionals in the state who indicated that injury was severe in some cases, and minimal in others – microclimates and differences in exposure likely had a lot to do with that.   Yukon bermudagrass, a seeded cultivar, had almost no winter injury at Wildcat Creek Golf and Fitness in Manhattan (Fig 2). This was impressive considering it was seeded in 2017.

Fig. 2. Yukon Bermuda, seeded in the summer of 2017 by Kevin Fateley at Wildcat Creek Golf and Fitness in Manhattan, KS showed very good recovery in May and almost no winter injury.

Fortunately, it has been a great summer for recovery. High temperatures above 100 F and lows in the mid 70s speed the growth and spread of bermuda. Unfortunately, it’s been another one of those hard summers for cool-season grasses. Here we are in Kansas trying to cope with the wrath of extreme winter and summer temperatures – been here, done this.