[rosenlof/lucas]

Hey all you northerners,

A design we did recently involved three large planters on wheels/casters. They were eight feet long, 36 inches high, and 18 inches wide.
Very big and heavy and very cool looking.
They were planted with eight Boxwood hedges each.
The idea is they will get tall and eventually become like a giant mobile fence.
At the time we built them, we were assured by a greenhouse plant specialist that they would be fine in the winter.
However, a new trusted source says she doubts "they'll make it through the winter if they're not in the ground".

Is she right?
if so
What can I do to correct this?
or make the odds for survival better?

I'm in Minneapolis Minnesota, it gets pretty cold here.

I've got my fingers crossed.

Thanks,
Matt

rosenlof/lucas

[Stonehenge]

I would trust your trusted source - those roots will be exposed to extreme cold on every side, and make it very tough on those plants.

You could mulch up around the entire planter, but that's not a very attractive solution, IMHO.

[rosenlof/lucas]

Thanks Stonhenge,

What about this. They are mobile and will be rolled into the garage for the winter (not-heated).
If one was to place bails of hay around them and cover them, would this improve our odds?

Any other ideas?

Thanks,
Matt

rosenlof/lucas

[GLAN]

I like your idea


OK.....

Here is how I see it. The boxes would freeze solid and the plants would have no way of getting any water. Comes spring they would be desicated beyond belief.

First spray them with "Wilt Proof" and do so 2 or 3x during the winter. Put them in a sheltered area West, South or South/East exposiure. Stack them together. I would try wraping with insulation and covering with plastic. I wouldn't want to dig in the planters or try to mulch around them. But mulching is doable.

two or three times a month water the planters.


The idea here is to shelter them in some way........prevent winds from just blowing through the plants day after day, after day. And to keep the boxes from freezing for any great length of time. And making sure there is enough water in the boxes for the plants needs.

[ianc]

line the box with SM Stryofoam - I do this when I put plants in Cement Planters

frost will freeze-dry the roots and drive in horizontally - water well in the fall

[GLAN]

Originally posted by rosenlof/lucas
Thanks Stonhenge,

What about this. They are mobile and will be rolled into the garage for the winter (not-heated).
If one was to place bails of hay around them and cover them, would this improve our odds?

Any other ideas?

Thanks,
Matt

rosenlof/lucas

The garage may work........roll them in at night.......out during the day and placing them along a south or south west wall. Monitor the water once a week or so

[LabourofLove]

Either or - moving into an unheated area or mulching with hay bales - ought to work. Once the snow comes and adds the 'blanket' to the hay, no worries. Be sure and put some critter bait underneath the planter because the rodents will like this moderately frozen soil much better than the actual outdoor ground.

I winter some very large pots of stock aboveground by putting wreathmaking scrap from the lip of the pot to the ground: making an airspace and holding the snow in place. Never a problem and I'm in Zone 3, too.

[dan deutekom]

Don't get overly complicated about it. If you water them well and then roll them into the garage for the winter (after they have gone dormant) they should be fine. Check every now and then check for moisture but once they have frozen they will be fine. The big trick is that once they start to thaw out make sure that they don't refreeze. In my experience it is not so much the harsh winter that kills planters but the thawing and refreezing that occurs in spring when you have warm weather thawing the roots and making things happen only to freeze solid at night. Plants in the ground generally thaw and stay that way.

[rivergirl]

I think GLAN has it. Especially wrap the long edge of the planter as it is only 18 inches wide.

What the heck is wreathmaking scraps?

[Paul]

Southern exposure would allow the planter to thaw in the warmth of the sun. A northern exposure would keep them frozen ( the root zone stay frozen all winter) What I have found is the root ball temps of planter fall below normal soil temps which is around 25 to 30 degrees then plants get harmed. Snow a great insulator keeps plants from drying out (freeze drying) water is one of the most important thing all plants need it's another insulator. Un heated garages get warm in the day time and cool off at night they might get too warm and activate the plant too early.

Place them on the North side and cover with hay bales and mulch water well and keep them hydrated.

This only come from doing a couple dozen streetscapes with Chicago winters.

[LabourofLove]

Originally posted by rivergirl
I think GLAN has it. Especially wrap the long edge of the planter as it is only 18 inches wide.

What the heck is wreathmaking scraps?

It's the leftover branches with bits of green still on the branch (but not long or big enough to use for the wreaths).

[Lanelle]

Two of the worst things that can happen to a boxwood in the winter are desication of the foliage and exposing the leaves to the early morning sun. That causes a rapid change in temperature in the foliage so that the leaves 'thaw' out too fast and will turn that odd orange color. So, don't store them on the southeast side of the building. The traditional way of protecting boxwoods in the winter includes wrapping the body of the plant with burlap so that the snow doesn't break the plant apart. Adding other things for insulation is a good idea and a snow will protect them. Definitely protect the roots from 'freeze drying' as Paul says.

[GLAN]

Interesting

That orange color.........I never attributed that to morning thaws of the foliage. Honestly though......I don't seem to see it on Boxwoods as I do on Larger Ilex. I guess it makes sense.......the condition is worse in the harsher and colder winters.......rather than when we have periodic thaws. But the do recover nicely, at least those that we care for do

My only concern here is the containers.....the concensus here is to not allow the containers getting to cold.....That would mean keeping the plants in a semidormant state..........where the roots are active and the plant can take in water.

Years ago I screened some new plantings with burlap.....Wondering if doing that with these containers keeping the sun off the foliage would help if they had to brought out to a Southern exposure during the day?