Winter Kill - 2010 - Part 3

Winterkill 2010?
With colder than normal temperatures in Arkansas this winter, we are anticipating that some of our turfgrasses around the state may suffer from winterkill. To help prepare for this we are publishing a four part series on this topic to help turfgrass managers prepare for what may await them in the spring. Look forward to the following topics over the next four weeks.

Part I: Predicting the damage: What causes winterkill and how can we estimate our losses?
Part II: Preparation and recovery: What should you do or not do this spring to help your turf?
Part III: Planning and planting improved cultivars for a better future.
Part IV: Practices to enhance winter survival.

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February 4, 2010

Part III: Planning and planting improved cultivars for a better future.

Arkansas lies in the transitional climatic zone. What this means is that summer in Arkansas is too hot for cool-season grasses to perform well and winters are often cold enough to injure or kill warm-season grasses. Unfortu­nately, maintaining lawn grasses in the transition zone is more difficult than in many other parts of the United States. Table 1 indicates conservative estimates of the relative winter hardiness of warm-season turfgrasses in Arkansas. Winters in Fayetteville are too cold for St. Augustinegrass and centipedegrass, and the summer heat and humidity in Texarkana make it difficult to grow tall fescue. Zoysia­grass and bermuda­grass are grown in all parts of the state. We rarely have winter damage to zoysiagrass, but cold weather injury to bermudagrass is not unusual in Northern Arkansas.

The genetics of the plant is the most important factor that will decide whether or not a plant can survive winter. It is extremely important to choose and plant a cultivar with good winter hardiness when planting a grass at the northern fringe of its adaptation zone. An example of this can be seen with bermudagrass in northwest Arkansas. Varieties like Riviera and Yukon bermudagrass are well adapted to NWA but varieties like Princess 77 are not reliably winter hardy in NWA. None of the ultra-dwarf bermudagrass varieties (Miniverde, TifEagle, Champion) used in southern Arkansas are reliably winter hardy in NWA.  After this winter, we may find out if they are reliably winter hardy in central Arkansas. Even with zoysiagrass, which has better cold hardiness than bermudagrass, Meyer and El Toro are adapted to NWA but Diamond zoysiagrass is as well-adapted.

Table 1. Comparing winter hardiness of commonly used cultivars and species of warm-season grasses.

 

Bermudagrass

Centipedegrass

St. Augustinegrass

Zoysiagrass

Excellent

 

 

 

‘Compadre’*, ‘Meyer’, ‘Zenith’*,

Very good

‘Midlawn’, ‘Patriot’, ‘Quickstand’, ‘Riviera’*, ‘Yukon’*

 

 

‘Cavalier’, ‘Crowne’, ‘El Toro’, ‘Emerald’ ‘Himeno’, ‘Palisades’, ‘Zorro’

Good

‘Barbados’*, ‘Contessa’*, ‘Sovereign’, ‘Tifsport’, ‘Tifway’, ‘U-3’

 

 

‘Empire’, ‘Diamond’

Fair (central and southern Arkansas)

‘Jackpot’*,  ‘Princess 77’*, ‘Tifdwarf’, ‘Tifgreen’

‘TifBlair’*

‘Raleigh’, ‘Texas common’,

 

Poor (southern Arkansas only)

‘Arizona common’*, ‘Sahara’*

‘Common’, ‘Oaklawn’

‘Floratam’, ‘Floralawn’, ‘Seville’

 

* Indicates cultivars with seed availability. Some cultivars may not be available at local seed suppliers and require a special order.

There are many cultivars used in Arkansas that are not on the list above. Current research should help determine the winter adaptability of these cultivars and work is ongoing to expand the details of the above table.

Dr. Aaron Patton