Winter tree protection
In the upper midwest, and especially out on the prairie, some young trees need protection from the harsh winter conditions. Not all tree species will, but those with thin bark and any that taste good to animals will need some extra care.
Here is the interesting thing about bark protection. It needs to be done in the winter, but must be removed after the threat of damage is gone in the spring. If you look closely at those young shoots and trunks (maybe scratch lightly) you will see green. Green means that there is chlorophyll, and chlorophyll means that the tree is producing sugar from the sunlight through photosynthesis. This means that the more you cover it up, the less the tree will be able to produce food for its self and thus take longer to establish, grow, fight off pests, and recover from stress.
So what is the pest protection? First, I’ll mention all the methods I’ve heard of, then I’ll mention whats best and why; There is white corrugated plastic tubing, black corrugated plastic tubing, burlap, white latex paint, wooden boxes, wire mesh (chicken fence, etc.), and straw bails. In my opinion, the best use for both ease of use and functionality is the white corrugated plastic tubing (4 inch diameter). The black tubing heats up too fast in the late winter sun and can still lead to frost cracks if its touching the trunk. Paint cannot be removed as mentioned above so thats not good. Wire mesh keeps the animals away, but may not provide enough sun blocking protection, burlap touches the bark and deteriorates away to fast and sags down the trunk when wet, and the rest are just not necessary. The 4 inch diameter tubing should be big enough to cover the trunk of the young trees without touching or rubbing on the trunk and last many years. Plus it is easy to put on and take off. Only the while tubing will work well for those trees other than fruit bearing trees that protection (maples especially). For your fruit trees, there is another step you will need to take.
Fruit trees are susceptible, not only to sun scald and frost cracking in the late winter months, but can succumb to rodents at about any time of year. That is because they taste good. So to protect the trunk of young fruit trees you will need to incorporate hardware cloth and the white corrugated plastic tubing. The hardware cloth (small squared metal mesh fencing. Go to Ace hardware and ask for it. A good hardware store will have it.) will go on relatively tight around the trunk. Push it a few inches into the ground to protect rom the voles and moles, and have it go high enough up the trunk to stop the rabbits when the snow is high. This will stay on year round. It will still allow for light to reach the trunk, but the rodents can’t chew through it when desperate and hungry. Just keep in mind you will have to remove it as the tree grows, or you’ll kill it by girdling the trunk. Then in the fall you can place the white tubing over the hardware cloth, and remove come spring thaw.
If you haven’t done this yet this winter, (its now late January) it is not too late. It has been a cold winter, but the sun shouldn’t have had enough power yet to have done its damage. Sun scald and/or frost cracks occur when the warm late February sun heats up the surface of the bark later in the day. But when the sun sets or goes behind clouds, the temperature quickly drops and that sudden change causes the bark to separate from the young wood underneath.
Remember, the key to trees is prevention. Once a wound or damage has occurred, it will be there ‘forever’. Trees do not heal, they can only grow over the wound. That will take excess energy which can reduce growth or make the tree susceptible to pests or death.