Orchardist Harry Roberts said Earnscleugh was a "hive of activity" on Wednesday night as growers kept an eye on irrigation systems which were helping to protect fruit blossom.
"But it's all just part of the job."
His orchard reached a low of -4degC overnight but he said he had been prepared.
"You don't get away with a weather pattern like that [with snow falling] without getting something out of it."
While he could not estimate how much water he had used, come morning, 80ha worth of trees were covered in icicles.
But the frost-fighting was not confined to orchards around Alexandra.
Cromwell orchardist Mark Jackson also had a sleepless night as temperatures on his 30ha orchard dropped to -1degC.
He said he had been on alert since Monday.
Summerfruit New Zealand chairman and Teviot Valley orchardist Gary Bennetts said he too was up frost-fighting, as temperatures fell to about -3degC.
Fellow Teviot Valley orchardist Stephen Jeffery said while it was the first night he had turned the water on to fight frost, he had been up several other nights to keep an eye on temperatures.
On Wednesday night, he ran his irrigation system for 12 hours.
He said it was quite a hard frost. They would normally only have water on for about four to six hours.
It was mostly apricots, as well as some nectarines and plums that were the most vulnerable, orchardists said.
Mr Roberts said apricots were particularly vulnerable as the petals were already starting to fall, or had completely fallen in some areas like Roxburgh, meaning fruit starting to form and had less protection.
While frost-fighting meant a sleepless night, the following day when they were busy checking water levels in the dams, diesel in the motors and oil in the pumps, orchardists remained optimistic: " ... otherwise we wouldn't do it", Mr Bennetts said.
Mr Roberts expected another frosty night "before the week is out".
The water orchardists sprayed on blossoms froze, protecting them from the harsher frost.
