Q: Hello, I have a dwarf Alberta spruce that has been in a large pot on our deck since Spring. I would like to leave it in the pot for the winter without bringing it in the house but am unsure of the proper method of protecting it from the Northeast (upper NYS) elements. Do you have any suggestions? Thank you!
A: I strongly caution against leaving the plant outside in its pot. The roots will be totally exposed to the cold. If they freeze, bye-bye sprucie!
If there is some way to protect the pot from freezing, such as partially burying it and mulching the rest, that would be better.
Or if you can construct something to go around the pot to accomplish the same goal (keeping the pot, and the roots contained therein, from freezing). Otherwise, if there's some place you can store it, like in an unheated garage, that may work, too.
I prefer the "bury the pot part way and mulching it" method, though. You can't be sure of the conditions inside an unheated building.
Partially "planting" the spruce in its pot more closely resembles the natural condition of being in the ground to begin with. Be sure to water the plant if you have a dry winter, too.
Q:I just received a potted Alberta spruce and need to know how to care for it during the winter; the ground is already frozen?
If the ground in your area is truly frozen too deeply to allow digging a hole for the spruce, you can overwinter it anywhere outside. Place it in a sheltered spot, out of direct wind and sun. Protect the pot with mulch or leaves piled up snugly around it on all sides from top to bottom. This is to protect the roots.
The root system of plants in above-ground containers have more exposure to the cold as they don't have the benefit of soil all around them (other than what's in the pot itself) to protect them from the cold.
As such, the roots are totally exposed on all sides, not just the top, and if they totally freeze, the plant may end up totally dead.
You may want to see if the ground really is frozen too deeply to dig a hole at this time. You may just have a "crust" of frozen soil, and the soil beneath is still diggable.
If so, dig a hole twice the width of the pot and the same depth or slightly less. Then carefully remove the spruce from the pot and place it in the hole. Chop up the soil you removed as finely as you can and place it back around the root ball a few inches deep at a time, lightly walking or stepping on it to tamp it down as you go.
When finished, 2-3" of mulch (wood chips, shredded bark or leaves are perfect) will help protect the top of the roots from extremes in temperature. It wouldn't hurt to apply a few gallons of water before mulching it, too. This should get your potted plant through all but the coldest of winters.
Q:Can I use "Ultra-Fine" pesticidal oil on my potted spruce in the winter now in Rhode Island? Also can I put the potted spruce in a garage which gets down to but not quite freezing? Thanks for your response.
A: Dwarf Alberta spruces are sensitive to oil, so I'd check the label to see if it says this product is safe to use on them. If the label says nothing about it, I'd play it safe and not apply it to the spruce.
Your potted spruce can be overwintered in an unheated garage. Check the soil at least once a week, and water if it's dry.
Thoroughly soak the soil down to 4-6" deep, but allow time in between waterings for the soil to dry out some. Otherwise, you'll waterlog it.
Ask our Arborist a question. E-Mail us at:
Top of Page
Back to Lawn & Garden