Does hardiness of perenials depend on depth or medium of material
Just wondering if plants that are perenials are not hardy when not planted in the ground. For example had some Echinachea, Goblin and Lupine in pots that didn't come back while lupine planted did. ?!? The frost line doent cease until much farther than these plant roots so what's happening here?
I'd also like to plant a small dwarf Cherry Tree in a homeade planter/bed for the time being until I move and get some real space. Will this likely be able to survive? The plant label claims it's hardy to -20 to -30