Frost Damage

 

Frost Damage - New growth on this Flame Seedless
Grape Vine has severe frost damage.



Frost is a threat that all growers face. It doesn't matter if you are farming commercially or you are in your backyard. The damage that a frost can cause to new foliage can be devastating. As I discussed in a previous post, I had a worry about this issue due to the early blossoming of some of my fruit trees. However, being almost in mid April, this fear has dissipated. I was wrong.

In my excitement about the grapes, my apricots, and the kiwi vine that had new growth, I have had another setback in my efforts to provide a healthy crop of fruit. However, in my frustration, I would like to take the time to share with you what I have done with my one citrus tree. The approach taken with this tree could have easily been applied to each of the fruits that suffered from frost damage and I would have not felt the need to post today.

Partial Frost Damage - this grape vine experienced
mild frost damage as can be seen by both damaged
growth and live, undamaged growth.

Grapes

I have four grape vines. Two of these are espaliered on a block wall so they gain the night time protection and heat that a wall provides for the new growth. The other two are free standing in an area that does not offer the same level of protection. While the trunks are well protected by the rough papery bark, the new growth is exposed to the cold night air. There was significant development of flower clusters which would have produced volumes of grapes this season. While there are still some clusters left, the majority of these have been destroyed. This could have been easily prevented by simply placing a sheet or a tarp over the trellis system to retain some heat over the night.





Whithered Apricots - All that is left of the numerous
apricots that did not survive the frost.



Apricot

The tree that everyone should have in their yard, and a tree that I have planted three in mine, has suffered from this as well. With branched loaded with the newly set fruit, I was excited for the end of June when I would be able to harvest from my Royal Blenheim Apricot. Unfortunately the fruit that has set is now withered and dead. This could have easily been avoided by providing similar protection to the grape or what I describe below for the Satsuma Mandarin Orange.

 

Kiwi



The frost damage to the Kiwi occurred a few more weeks back. I showed these plants in my first post and they were lush and green before I had planet them. They were victim to a frost about three weeks ago, but they have since shown signs of new growth. To protect these smaller plants that are sensitive to the frost, I use empty potted tree containers that I have saved. Just simply turn them upside down over the plant. This will contain some of the heat, but will also provide the ventilation through the drain holes to prevent the moisture from accumulating within the protected area.



Hard to see what's left - This Kiwi plant was killed to
the ground from frost damage





Satsuma Mandarin Orange

When I first thought of growing citrus, I looked far and wide for a citrus tree that is hardy to lower temperatures. While the Satsuma Mandarin Orange can tolerate colder temperatures, it still is not advisable to allow the tree to be exposed to temperatures of less than 30 degrees for more than a couple hours. This orange in particular has been said to tolerate temperatures down to 24 degrees. In my area, the temperatures can get into the teens. So what do you do then? By planting the tree against a wall you can provide some protection, but not always enough.



Strange as it looks, this approach protected my
Satsuma Mandarin through the cold winter.





To protect my tree, I use some of my old C-9 sized Christmas lights. They generate enough heat to keep the tree warm. The drawback is that these lights will create additional cost in your electric bill. You can simply turn them on every night, but then you run the risk of forgetting one night, and one night is all it takes to kill the tree. To combat the cost and the risk of forgetfulness, I have purchased a Thermostatic Outlet that will turn on at 35 degrees and will turn off at 45 degrees. This has provided me with the added assurance that the lights will come on only during the times that there is a real risk to the tree. So far I have made it through one winter with no more than a few leaves that had been damaged. This spring the tree is quickly producing new growth and hopefully a nice crop of sweet mandarin oranges.

They say that "hindsight is 20-20", and I hope that in the future my complacency will not allow me to forget to check the expected night-time temperatures. These temperatures are easy to check at http://www.weather.gov/ so don't you forget.

-Backyard Gardener