Frost Risk for Northern NY Tomorrow Morning 

Mike Basedow 

We have a frost risk through much of Northern NY early Thursday morning.  Here are some of the forecasted lows and windspeeds for a few locations throughout the region early tomorrow morning: 

Clifton Park: 31, wind  2-3 mph 

Burnt Hills: 31, wind 3-5 mph  

Fonda: 28, wind 2-3 mph 

Granville: 27, wind 2-3 mph 

Crown Point: 34, wind 2-4 mph 

Peru: 31, wind 3-5 mph 

Chazy: 30, wind 3-5 mph  

 

Below are the critical temps for our various tree fruits, with 10% and 90% kill temperatures listed for the various growth stages: 

 

  

Tables compiled by Mark Longstroth, MSU Extension Educator, all photos by Mark Longstroth (MSUE) 

If your lows are approaching these critical temps, and you’re going to have calm wind conditions, this would be a morning to run your wind machines.  Wind machines won’t do much if you have a steady wind, but there isn’t much wind associated with this event. Where low wind conditions are forecasted, mowing row middles can also help ahead of the cold, as this will allow the soil to absorb and then radiate heat more effectively.   

Other mediation strategies from MSU include: 

• Under-tree micro-sprinklers will provide heat from groundwater into the orchard. Start the system a couple of hours before temps get too cold to prevent freezing up the system (perhaps 2 to 4 F). Unlike overhead sprinklers, it is not critical that the ice stay wet because the ice forms on the ground not on the flowers. 
• Overhead sprinklers protect plants by using the heat given up by water when it turns from a liquid to a solid to warm the plants. Growers continuously add water, which turns to ice. It is critical to keep the ice wet, and it will stay at 32 F (see “Using sprinklers to protect plants from spring freezes”). This requires large amounts of water and the weight of the ice often breaks branches. 
• Herbicide strips under tree rows help. Bare soils will absorb heat and provide radiation heat to trees overnight (perhaps 1 to 2 F). Do NOT work soils prior to a freeze event—this situation loses heat faster than undisturbed soil. 
• Mow grass drives and in-rows very close to the ground. Short grass will allow exposed soil to absorb heat all day from sunny conditions to release all night to the trees (perhaps 1 to 2 F). 
• Wet soils absorb more daytime heat because the water can load a lot of heat and radiates heat back out at night. Irrigate to wet dry soils as much as possible before the frost event. Start trickle early enough to thoroughly wet orchard before the frost. Run irrigation (trickle) the night of the freeze. Trickle will probably freeze up during the frost event (perhaps 1 to 2 F). 

• Check your irrigation system. Crack the values on manifolds to avoid freeze damage to irrigation systems. 
• Nutrient sprays could strengthen fruitlets to resist freezing temperatures (perhaps 0.5 to 1 F). 
• If allowable, burning wood and hay would provide heat to the orchard for only small areas (a few feet) near the fire. Place small piles of firewood down the center of every or row and light every other pile at 3 a.m. and then at 5 a.m. start the other piles. Each will burn to roughly 2 hours (perhaps 1 to 4 F). Try to keep smoke to a minimum. The heat will radiate skyward right through the smoke and the smoke will slow heating after the sun comes up.  
• More details can be found in the original MSU article here: https://www.canr.msu.edu/news/what-can-fruit-growers-do-if-a-freeze-is-coming 

Also keep in mind that the added cold stress may allow for fruits to thin more easily.  Take this into consideration when planning out your future thinning applications.