Helicopters are being used to fight frost on this year's cherry crop

If you've been hearing helicopters at the crack of dawn over the past few weeks you're not alone.

Bruce Morrison sent us a short video and a few pictures of a low-flying helicopter in the East Kelowna area, "this morning (Saturday), starting at 6 a.m., there was a low-flying helicopter doing laps over an East Kelowna property and surrounding parks and structures until 6:50 a.m. They were an estimated 30 feet above the ground (and) were almost right above my vehicle at one point while parked on the shoulder of the road."    

Okanagan residents are familiar with helicopters using their blades to clear off rain and dew build-up on cherries as they get closer to harvest, but perhaps have not heard that cherry farmers also use helicopters in the spring to ward off frost.

A local helicopter operator tells Castanet during some springs, in late March and early April, frost can damage cherry tree buds. 

Once daytime temperatures begin to rise some cherry buds begin to flower, but if cooler temperatures follow the next day, especially in the morning, frost can kill the buds, damage the tree and set the growing process back.

High temperatures for Kelowna are expected to be in the mid-teens this week but the forecast for Wednesday morning is calling for a low of -1 C.

"The coldest part of the day is in the morning, that's why it's important to circulate the air in the morning," said the helicopter pilot, who has been flying in Kelowna for the past 10 years.

Hank Markgraf is a Kelowna orchardist and a board member with the International Tree Fruit Association and an orchardist, he says the technique has been used for the past 20 or 30 years in New Zealand and Australia but not so much here in the Okanagan.

"We haven't used (helicopters) them that much but we haven't had that many cold springs either. This is definitely a colder one for us for sure, it's been two or three years since we've had a cool spring like this one," says Markgraf.

Orchardists use the helicopters to move an inversion or to capture warm air hovering just above the orchard and push it back down into the orchard. Markgraf says it is relatively expensive to use helicopters but farmers weigh the cost of losing a portion of their crops versus the expense of hiring a helicopter.

"Our cherries are in that tender timing right now. The orchards have woken up but we still have cold temperatures in the morning."  

Markgraf says the sounds of helicopters fighting frost will continue until we are through the cherry blossom season, "every morning that's below zero is a danger morning for us." The cold is a danger to all tree fruits, including vineyards, but cherries are ahead right now and farmers can typically get a higher return for cherries, especially in foreign markets.

"It's different for each tree fruit but as we know Canadian cherries right now are highly valued in the far east so they return a lot of money," says Markgraf.

Some orchardists also use wind machines to help control the average temperature in their orchards at the most critical times of the year.

Spring frost and winter freezes threaten stone fruit, like cherries, peaches, and apricots but wind machines and helicopters provide protection at crucial times of the growing season.

Some farmers even use drones as a means to measure the temperature and dispersal of air as it is pushed around orchards by these types of fans.