Ice on the Mandarin Trees

From the Fields - Farm News, January 21, 2013

I awake sometime after midnight thinking about the orchard of mandarin trees we planted last spring. They are frost-hardy; it is the reason we selected them. Literature says they can handle a few hours at 27 degrees F. I am not worried about the established orchards. Their new growth might get burned back a bit, but they will live. It is this orchard we planted last spring that I worry about. This is their most vulnerable season. Lying awake in bed, I realize this cold snap is most likely their most vulnerable 72 hours. Mom lost a new orchard to a hard frost when I was a child. I remember the financial and emotional toll it took in our home.

Our plan had been set a week ago. Turn the water on at midnight. An irrigation system wetting the orchard with water does two things; it adds as small amount of energy due to the warmth of the water. The freezing of water is an exothermic reaction, which means that when water freezes, it releases a small amount of energy. The other thing we have going for us is the location of the orchard. It was placed on a small hill that sits above the valley that allows the dense cold air to drain off the orchard.

I think about the tree wrap we installed to protect the base of the trees from rodents and the 2 degrees of frost protection the salesman said they delivered. I don’t believe him, but I want to. There are the wind machines that we don’t have that could protect the trees and for one moment, I wish that we did. I can see a picture of someone selling helicopter services in an ag magazine. I think that paying someone to fly around the orchard in a helicopter at night is dangerous and not effective, but I do think about it. The single degree that separates your orchard from life and death is an elusive, but finite fact that will absorb as much time and money as you will give it.

On my drive over to the orchard first thing in the morning, I pass my farm manager returning from it. I arrive to a winter wonderland, micro sprinklers running and ice everywhere. It is pretty. I stop to take photos. Most of the ice is on the ground and on the base of the tree, the leaves have no ice, but they look as cold as the ice below them.

On the hill, there is a line where the irrigation water did not turn into ice (you can see this in the photo above).  The bulk of the orchard is below the line, sitting in what I hope to be a protective layer of ice. It crosses my mind that I don’t know what dead mandarin trees look like, and I hope I never do. The ones I am looking at could be alive or they could be dead. I shout out to them, “How you guys feeling – did you make it? Got another cold night coming.” They don’t respond. 

As I drive back to the office, I pass my brother heading to the orchard. It is a popular place this morning. Chatting with our farm manager, we both agree that it wasn’t that cold, and they might get burned a bit, but they will live. Being optimistic is a prerequisite for being a farmer. We both agree that we won’t know for a week or so. 


Many of you have asked, how are the trees doing now?

The trees look great and we didn't loose a single tree! They were planted on a hill, so the cold air rolled right off.  Thank you for asking, and for thinking of us.

We are looking forward to another good year of growth on them this year!