Chilling hours for peaches generally on target across the state

It’s usually best to wait until after the last possible freeze date to prune peach trees, according to Monte Nesbitt, Texas A&M AgriLife Extension Service horticulturist, College Station. However, commercial growers with hundreds or thousands of trees have to get a head start on the process by starting to prune in the winter. (Texas A&M AgriLife Extension Service photo by Robert Burns)

Writer: Robert Burns, 903-834-6191,

COLLEGE STATION – It’s been a generally mild winter, and the state’s peach orchards have pretty much been doing what one would expect: “chilling,” said Monte Nesbitt, Texas A&M AgriLife Extension Service pecan, fruit and citrus specialist, College Station.

Nesbitt is, of course, referring to “chilling hours,” the number of hours of cold temperatures during the winter that fruit trees “need to satisfy winter rest requirements and produce a good crop.”

“I talked to (AgriLife) Extension specialist Jim Kamas at Fredericksburg yesterday, and he said he thought they were at about 750 chilling hours in that part of the Hill Country, which is about average for this time of year,” Nesbitt said. “In College Station, we’re at about 450 to 500 chilling hours, so we are running a little behind. Normal total winter chilling for College Station is 600 to 650 chilling hours, but it doesn’t take many cold nights to catch up.”
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Additional cold nights this month would be helpful, Nesbitt noted.

There are different methods to calculate chilling hours, but the ones that most horticulturists prescribe to is simply the number of hours of temperatures below 45 degrees. The other method does not count hours below 32 degrees, he said.

“Methods of chill hour tabulation also vary according to when to start calculating hours. Some methods arbitrarily commence on a calendar date in the fall, like Nov. 1,” he said. “My colleagues and I find more accuracy by tabulating hours after experiencing a 32 degree temperature event. For Fredericksburg, that was Nov. 22, according to Kamas.”

The weather webpage for the Texas A&M AgriLife Research and Extension Center at Overton at tracks both methods. From October through the first week of February shows 713 chilling hours by the preferred method, which is also close to target.

Another way to get chilling hours specific to an area is to use the Get Chill Hours! website at, Nesbitt said.

Getting the hours is a two-step process but worth the effort, he said. First go to WunderMap, for which there is a link on the Get Chill Hours! main page. Click on a weather station icon in your area to get the station’s ID. The code for Tyler, for example, is KTXTYLER22. Enter the code in the Get Chill Hours! front page, as well as the start date and end dates, and the chilling hours will be automatically calculated in seconds.

Nesbitt recommended making the calculation using multiple sites to account for quirks with missing data and site variability.

With chilling hours generally good, the only concern Nesbitt expressed was that owners of small orchards often start pruning too early.

Traditionally, it is thought that fruit trees should be pruned during the winter, but for people in Texas who have a small number of trees, it’s a better idea to wait until spring, he said.

“Pruning can slightly stimulate bud activity, and growing buds are more susceptible to a late frost or freeze,” Nesbitt said. “And you’re also removing branches or limbs that can help protect the lower parts of the tree in certain types of frosts. Our problem in Texas is that once chilling has been satisfied, warm temperatures cause buds to break dormancy, making us vulnerable to late frost. Pruning can work against us in that regard. Wait as long as possible — until after the last frost to prune; it’s okay to do that.”

Nesbitt noted that commercial growers who have hundreds or thousands of trees and rely on pruning to thin the next crop can’t wait too late to start that process. They have to begin pruning in the winter.

AgriLife Extension district reporters compiled the following summaries:

The 12 Texas A&M AgriLife Extension Districts

Central: Soil moisture, rangeland, pastures, crops and livestock were all generally in good condition throughout the region. Nights were cool to cold with an occasional hard frost. Producers still had fields that were too wet to be worked, but were catching up each day as soils began to dry out. Crops were in normal condition for this time of year. Livestock producers were still providing supplemental feed to cattle. Warmer weather helped winter forages grow. Wheat for grazing remains behind in development. Farmers were applying preplant fertilizer to fields they will plant in corn, small grains or sorghum. Corn planting was expected to start about Feb. 15.

Coastal Bend: Cool, windy weather and a lack of precipitation dried out topsoils considerably, but there remained good subsoil moisture. Some corn was planted, but farmers hoped for rain before beginning spring planting in earnest. Producers continued fertilizing and controlling weeds. Rangeland was in fair shape. Cattle were still in good condition. Livestock producers were doing a considerable amount of supplemental feeding, especially with hay, since most had ample supplies.

East: Cold and dry conditions reigned across most of the region. Fields and pastures were drying out. Pasture and rangeland remained mostly in poor condition, with some areas rated as very poor. Most counties had adequate subsoil and topsoil moisture. No rain along with high winds raised wildfire danger. Forages continued to improve with more sunny days. However, winter pastures still did not look good due to too much rain, cloudy days and delayed fertilizer applications. Farmers were topdressing winter pastures where possible. Livestock were in good condition as producers continued supplementation. Cows were calving. Vegetable growers were planting onions and potatoes. Fruit orchard managers were pruning trees. Feral hog activity continued to rise as the animals were evicted from creek and river bottoms by floodwaters.

Far West: Windy, cool conditions dried out fields and rangeland, which resulted in high wildfire danger. Leaf rust and winter grain mites were reported in Glasscock County. Producers continued to prepare fields for cotton planting. Most producers were providing livestock with supplemental feed. Early calving herds began to drop calves, and sheep ranchers were preparing for lamb crops. Rangeland and pastures were in fair to poor condition. Topsoil and subsoil moisture were adequate to short.

North: Topsoil moisture varied from adequate to surplus, with a few counties reporting shortages. Conditions were mostly mild, with temperatures dipping to around freezing on several nights. Sunshine and warm weather dried out fields and pastures well enough to turn cattle in for grazing. There were still some areas too wet to sustain cattle traffic. But it was getting dry enough to topdress with fertilizer without equipment leaving ruts. Wheat and oats showed growth. Pasture and rangeland were greening a little, particularly from winter grasses such as ryegrass. Warmer daytime temperatures caused some fruit and nut trees to bud. Corn and grain sorghum growers tried to get a head start on preparing fields for planting in April and May. Wild hogs caused a lot of damage.

Panhandle: The region did not receive any precipitation during the reporting period. Farmers across the region were able to get into fields to strip till, apply herbicides and fertilizers, and otherwise prepare for spring planting. Winter wheat could use moisture, but it remained in fair to excellent condition across the region. Cotton harvesting was finished in all but a few counties. Cattle on grass were in good shape, with producers continuing to supply supplemental feed. Burn bans were implemented in several counties.

Rolling Plains: Conditions were mild, but high winds raised wildfire danger. Cotton harvesting was winding down. Topsoil was beginning to dry out, especially in fields with early planted wheat. Small grains showed signs of stress. There was a report of stripe rust in one county. Some producers were beginning to topdress wheat as warmer weather brought a few patches out of dormancy.

South: Cold temperatures and dry conditions continued throughout the region. There were no reports of any rain, but the northern and western counties had freezing temperatures and/or light frosts. In the northern part of the region, northerly winds dried out topsoils. Potato planting was completed, with about 75 percent of the crop in Frio County already emerged. Also in Frio County, wheat and oat planting was finished and most of both crops had already emerged. Farmers were preparing fields for planting corn. With the lack of rain and declining topsoil moisture on rangeland and pastures, livestock producers in McMullen County had to continue to provide supplemental feed at a steady pace. Calving continued in most herds, and body condition scores remained fair. Soil moisture was adequate in Atascosa, Frio and LaSalle counties. In the eastern part of the region, pasture grasses remained dormant. Farmers were preparing to apply fertilizers. Brooks, Kleberg and Kenedy counties had adequate soil moisture, while Jim Wells County soil moisture was rated 100 percent short. In the western part of the region, the cold front brought freezing temperatures to Dimmit County for the first time this winter, while in Webb County, daytime highs rose to the mid 80s. Zapata County officials issued red-flag wildfire warnings and a burn ban because of dry conditions. Producers with irrigation capabilities were applying water to all crops in the county. Also in Zavala County, onions progressed well, but some growers were fighting noxious weeds in onion fields, as well as in cabbage and carrot fields. Spinach and cabbage harvesting continued. Soil moisture was adequate in Dimmit, Webb and Zapata counties, but was rated very short in Zavala County. In the southern part of the region, Hidalgo County growers continued harvesting sugarcane, citrus and vegetables. In Starr County, farmers were planting row crops. Fall vegetable crops were progressing well. Supplemental feeding of beef cattle continued on native rangeland and pastures. Soil moisture was adequate in all the southern counties.

South Plains: Garza County farmers continued to prepare fields for cotton planting. Planted cotton acreage was expected to be nearly the same as last year. Rangeland and pastures were mostly in good condition. Livestock producers were supplying supplemental feed on colder days. Cattle were in good condition. In Hockley County, no moisture was received; there was one very windy day that caused blowing soil. Farmers continued tilling ground, applying fertilizer and herbicides, and doing other fieldwork. Cooler temperatures were forecast for this week. Lubbock County had another week of mild and breezy weather. A warming trend was forecast, but no precipitation was expected. Farmers continued field preparation for this year’s crops. Producers were also trying to decide which crops to plant. Crop budgets indicated profit margins as being very tight or below the cost of production due to continued high input prices in conjunction with depressed commodity prices. One bright spot was lower fuel costs. In Scurry County, the weather was mild with no rain, with more of the same forecast for the upcoming week.

Southeast: Soil moisture throughout the region varied widely but was mostly adequate to surplus, with adequate ratings the most common. Fort Bend County had 100 percent adequate soil moisture; Walker County, 100 percent surplus. Rangeland and pasture ratings varied from fair to good, with good ratings being the most common. In Walker County, forages and vegetables were poised to start growing, waiting on warmer weather. Timber planting was underway. In Montgomery County, winter annuals had yet to show much growth. Hay consumption was up. In Fort Bend County, livestock were in good condition. With warmer weather, row crop farmers were doing fieldwork and hoping to plant corn soon if conditions permitted.

Southwest: Overall, topsoil moisture remained good, though a few areas with shallow soils had low levels. Pastures began to show signs of winter stress. There was no rain forecast. Livestock producers were feeding hay and protein.

West Central: The trend of mild, warm, windy days with cold nights continued. No rain reported. Wildfire potential was high. Cotton harvesting neared completion. Ginning was expected to be completed soon after. Fieldwork for spring planting was underway. Wheat and oat growth was slow; both crops needed warmer weather to stimulate growth. Rangeland and pastures remained in fair to good condition. Forbs and winter grasses continued good growth. Livestock were in fair to good condition with continued supplemental feeding. Cattle were grazing winter wheat.


Source: Agriculture Section – AgriLife Feed