best location to overwinter potted trees
I have two japanese maples and a few other potted deciduous shrubs that are reasonably hardy, but I want to give them the best chance for survival this winter. I think Munich is zone 6 and all of these plants are rated zone 5 or colder.
Even though I'm in the city, I actually have a rather large yard with a choice of locations where I could overwinter the plants, and wanted some feedback about what might be best:
1) north facing yard. This gets zero direct sun, and is really cool and damp year round. For sure the temperature is going to stay more constant to prevent freeze/thaw cycles but it really is chilly. There is a gravel border along the side of the building where drainage is good, and I am thinking there will be heat radiating from the building too...but only on one side of the pots. Good or not good?
2) east facing patio. This is definitely warmer year round, and in winter does not get any direct sun because it's too low in the sky. The patio has a "roof", but no sides The floor consists of concrete pavers so no drainage, but the only natural moisture would come from blowing snow. Lots of radiant heat here, good or not good?
Munich has funny winters as it's really not very cold most of the time, but we do get pretty severe cold snaps that can last up to a week. In the open north yard, I lost two fargesias last year, as well as a boxwood. On the other hand I had one hydrangea paniculata stashed agaist that north wall that did great, and a hydrangea macrophylla in the same location which barely made it.
In either location, I do intend to group all the containers together and pack bags of straw around them as well. Advice on how thick that layer of insulation should be would be great, too.
looking forward to hearing what you guys think!