THIS IS NOT A DRILL!
from Scott Elser
The cold weather has moderated somewhat due to the snow but we can expect low temeratures in the early morning hours and the forecast for Friday is for mid- to low-twenties. This is not all that uncommon in our area this time of year, and we had a bit of it last year. However, we have had unseasonably warm weather the past few weeks and some of our trees are beginning to bud out. Many folks are already into their repotting routine.
This makes our trees exceptionally vulnerable to cold right now. Here are some ideas on what you should be concerned about, and what you should not. This is really a sliding scale, with many factors. If you have been paying attention during some of our last few months of meetings, this will all seem familiar to you. First, let’s look at the most vulnerable trees. Those would be ANY TREE YOU HAVE JUST REPOTTED.
Doesn’t matter what size or species. By cutting and disturbing the roots, we’ve automatically reduced the winter hardiness of the tree. Just think of it as stepping out of the shower in a freezing snow storm. The Finns do it, but I am not recommending it.
All freshly repotted trees definitely need protection. A cold garage is great. If you have a greenhouse, consider yourself blessed, or reasonably prudent. Even a warm garage is better than putting the tree into a freezing situation. Your cardinal rule should be that any repotted tree never sees freezing conditions until it has a full growing season under its belt, or should we say canopy.
Next up let’s look at the stage of growth of your trees. Trees that bud out early are usually more cold tolerant than we expect. My crabapples chew up the cold, so even though they are starting to leaf out, I am not too worried. Even the shohin (under 10”). There might be a little damage on the tips, but it should be minimal. However, my precious “Anne Spencer” shohin Amur Maple is starting to leaf out, so you can bet it’s going to get great protection. Taking no chances here. The conifers have not yet even begun to wake up, at least in the foliage sense, so they should be good to go. Their roots are active though and that is what we are aiming to protect, so most of those will go on the ground. A light mulch of barkdust around to pot edges would not hurt.
Some of my trees are starting to graduate from one-man trees to two-main trees as I get older. When they are that big, they also have a big buffer of soil mass, so those stay on the benches. Your best and simplest strategy is simply placing your trees on the ground. On the flip side are the shohin. These little guys freeze all the way through very quickly, so protection is the best strategy here. Their small size means that they respond to ambient air temperature, so with the recent warm weather, they are also likely the trees that have budded out sooner. It’s easy to load them onto a nursery tray for the trip into the garage. Interestingly enough, accents don’t usually have as much of a problem. Probably because they are used to colder temps near the surface of the ground.
Predictions are for snow Sunday night and that would be awesome for the trees. A nice blanket of snow to protect from cold and wind. But it rarely seems as though mother nature cooperates with us in that fashion. I feel a little bit like doing trapeze without a net when it comes to winter protection, as I have very little for my trees. It’s a bit of a risk and gamble and these situations make it a little tougher. But I can’t worry or fret. I do my best and remember that the plants are much hardier than we give them credit for.