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Over-wintering potted plants
The cooler seasons are approching here in Idaho and I have been confronted with the challange of figuring out how to over winter an inventory of roughly 15,000 5g plants. Species varry between Native willows, Dogwoods,Hawthorns,Chokcherries, Snowberries, Woodsrose etc. In the past my company has stacked the pots and covered them with plastic but it is a great deal of manual labor to move that type of product and when it is all said and done the result was not that pleasing as a great deal of plant damage took place under the weight of the heavy snow on the plastic covering the plants. I have also heard that if you water the plants and then lay them on their sides for the winter this will help protect the roots. Are there any good ideas out there to help potted plants survive the winter months?
Replies to This Discussion
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Permalink Reply by Ed Hebbe IV on -
Danna,
You've got the basics of it down. You just need to do a bit of adjusting. Depending upon the weather conditions the closer it gets to winter, I try to wait until my pots are close to, if not already froze up. Instead of stacking your pots in an upright position, you lay them down pot to pot. And, you can also do some stacking, but laying down on one another.
I cover them with the white 4 mil plastic - sometimes doubling the thickness as this depends on the size of the plots I have - and weight the edges down well with whatever I have available. Oh, and don't forget - if you have an issue with mice and rodents in your area, be sure to place plenty of bar bait throughout the area you'll be covering. You may have to ck your bait stations occasionally through the winter months and replace any bar bait. It's not a nice sight to discover in the spring what those little creatures have done under the plastic.
I also place a few pallets here and there on top of this to hold the plastic in place for any high winter winds.
You also want to keep an eye on warm winter temps...here that's usually about the February time frame as you don't want your buds swelling or putting on any growth on any of the trees or shrubs. If it gets a bit too warm, roll up the edges around your covered plots so they can stay cool. Most of the time when I do this I basically leave them rolled up until I completely uncover them. I try to get them uncovered during March, though that has proven to be a bit challenging the past couple of years and it's been into April before I get them uncovered and placed upright again due to cool temps.
This has worked quite well for me over the years and I've lost some trees and shrubs to winter kill. You end up with some broken branches too, but that's expected with all the handling.
Otherwise, that's all that's to it. I don't have any pics right off hand, but need to do that this season.
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Permalink Reply by Sherwood Botsford on -
What I do is against all the rules. But it generally works. My potyard is pretty exposed to the northwest -- the direction we get bitterly cold breezes from for much of the winter.
I've tried three systems.
1. The pots are packed close together -- closest spacing.
They are surrounded with small square straw bales.
2. The pots are packed close together. No bales.
3. The pots occupy alternate squares in a hunk of concrete mesh suspended 10" off the ground.
(This last one is with Stuewe Tree pots, which tend to fall over with a harsh look.
ALL my trees are heavily mulched using old straw (fewer live seeds) The mulch fills the water space of the pot and runs an inch over the top when fresh, and covers the space between pots too.
Method one has almost zero losses.
Method two has some losses on the windward edge. At this time, don't know if that is drying from the wind or whether they didn't get enough water in the fall.
Method 3 has the most losses -- about 5% -- but this is the same place they grow. This may be a watering issue.
They get reduced water once we have a frost, then once the leaves drop they get a good soaking.
This works in Alberta (Zone 3b). We generally have a foot or so of snow most of the winter. Last year however it got down to -25 C for most of a week before we had snow. It works with Golden willow, laurel leaf willow, pussy willow, black maul willow, arctic blue willow, common osier willow and coyote willow. It works with blue, meyers, white, and serbian spruce. It works with ponderosa, scots, lodgepole, jack, red, mugo, mountain, bristlecone pines. It works with Swedish, trembling aspen. It works with Hill, Brooks #6, Balsam, and northwest poplar.
Jury is still out on eastern white pine, douglas fir, veitch fir, and concolor fir. I get a lot of tip burn on them. So I'm working up ways to raise them in the bush, where there is less wind.
My thoughts:
It's not so much how cold it gets, as how fast the pots freeze. If you can stop wind around the pots that may be enough.
As to why I don't get mice in that straw eating the bark off the trees? Don't know. There's a ton of mice running around at the bottom of the pots.
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