Q: I have several potted trees that I don’t think I am going to be able to plant this fall. The area they are going to go into is not ready to be graded to the final grade. There is a maple, an oak and two crabapples. How can I store the trees until spring? I won’t be able to fit them into the attached garage and I don’t have a shed.
A: What perfect timing! This past Friday—Oct. 6, 2023—I posted a video that will help you solve this problem. I have had to store large potted plants that I did not have the time to plant in the fall. I also have several large blueberry plants in pots that I need to store each winter.
If you have the space and equipment, you could temporarily plant the trees, still in their pots, into a temporary hole. Then in the spring, they could be unplanted from there and properly planted when the grade is ready. If you have a large dirt pile, they can be buried into that. Soil is great insulation.
Plants that are supposed to be growing outdoors in a cold climate have a problem. The top of the plant can easily handle the cold weather, even if we get a polar vortex blast of cold. On the other hand, the roots are only supposed to get down to freezing temperatures and not much below that. The roots are frozen in the soil, but they are not hardy to the extreme cold temperatures the top of the plant can handle.
If you just leave the plants outside, the roots will be damaged by temperatures in the teens and below. Covering the pots in insulation can mitigate the extremes and allow the roots to remain at the temperature of the frozen ground. Place the plants where they can be protected from winds that would dry out the trunks, branches and soil in the pot. If there is not much snow cover, you may need to throw a bucket or two of water on the pots a time or two over the winter.
An unheated shed will protect the top of the plants from winds and extremes in temperatures but may not be warm enough to protect the roots. An attached garage that isn’t directly heated will probably stay too warm for the top of the plant that needs to stay dormant. The top may even begin to grow leaves and flowers months too early to be planted outdoors in the spring.
My leaf blower has a vacuum attachment that shreds the leaves as it bags them. I use shredded leaves as the insulation. I cover the pots about a foot deep on top. I use some old siding boards to make walls around the pots and fill the space between the walls and pots with shredded leaves.
Snow is very beneficial as it is a good insulator. If there is enough snow available, it can be shoveled on top of the leaves and around the sides to doubly insulate the pots.
I wrap each tree trunk in wire mesh to prevent any mice or other rodents from eating the bark on the trunks that are buried in the leaves.
In the spring, you will need to remove the leaves as the weather starts warming up. Don’t let any new branches start growing under the pile of leaves. The new growth won’t be getting any light, so the new leaves will not be healthy.
I have used this technique several times. I have successfully overwintered fruit and shade trees, several species of shrubs, perennials and even a large potted prickly pear cactus.
Don’t wait until the last minute. Start now by figuring out where you can store the pots and start collecting leaves as they fall.
