I would dig up the ones you want and plant them in pots in well-draining soil. That way they will be ready to move when you need to move them. Bury the pots in a loose material of some kind, like hay, shredded leaves, wood chips, and once the plants have died back for the winter, cover the pile with something that will keep the whole pile relatively dry so that the insulation material doesn't get wet and pack down (or freeze together which would make moving them in midwinter difficult.) Until hard freeze, periodically check the plants to see if they need water and hand water them. In early spring, pull off the tarp, and fluff up the insulation if it has packed down so that the pots don't thaw and refreeze repeatedly. Let them thaw naturally and when it has warmed up, you can remove the mulch entirely. You will have to keep an eye on the plants to see if they need watering.

If you have an unheated garage or your shed is water tight you can put the pots in there for the winter and bring them back out in the spring. The freeze shouldn't hurt native perennials. I do this with some pots every year. I leave them out on my patio until I cut them back after a good freeze. Once they are in the garage I don't water them or even look at them again until early spring when I put them out just before new growth should begin. If there is some new growth already started be sure to harden it off or it will burn. Last fall I had so many to overwinter in the garage that I stacked some in boxes, one pot on top of another, didn't bother them a bit.

I also overwinter plants in dormancy in my cool dark basement but only ones that can't be frozen, tender perennials or tropicals.

babs said: I would dig up the ones you want and plant them in pots in well-draining soil.

==>>> lets define some words.. soil is mother earth.. she is NOT engineered for pots ... after a lot of experimenting.. you might succeed.. but we dont have time to try and fail ...

you use a potting MEDIA in pots ...

what i did.. when i moved 1650 hosta.. was go to the nearest nursery with a greenhouse.. and talked to the manager.. about what MEDIA he had available in bulk ... [large bags usually end up cheaper than 10 small retail bags] ....

then go to his recycle pile.. and select pots ... the smaller the pot.. the less media you use ... and get to work ... now is prime ... some uniformity of the pots really helps ...

the black pots can never be in winter sun .. they MIGHT freeze and thaw too often .. the key is GET THEM DORMANT.. KEEP THEM DORMANT...

once the pots freeze.. they can simply be tipped on their sides for the worst of winter.. this is to avoid accumulation of water in frozen media.. roots need air when dormant ... and if the whole of the media turns into an ice cube.. you lose ..

i stored about 750 pots this way.. on the north side of a structure [no direct sun].. and after freezing. i stacked them in a vertical triangle form against the barn ... [if you wait until the pots are frozen.. they may be frozen to the ground.. do NOT kick them or you might break a toe... so use something that wont break] ...

the only problem with a shed is that it might be a zone or two warmer ... which means your plants might start coming out of dormancy a month or two early .. and then you have problems ...

now.. to start ... you have to decide the value of the media.. pots if you have to buy them.. and finally.. YOUR TIME ... and decide if it is all worth it ...

i took my hosta collection because it was worth thousands of dollars ...

if you are simply dealing with a bunch of common.. rather cheap plants.. let me be the first to suggest.. that spending $100 on media.. for $50 dollars of plants.. plus spending 20 hours doing it all.. might not be cost effective ...

and in this case.. you take a long hard look at which plants are really worth the effort.. to save ...

===>> the other alternative.. is to find a friend.. who could 'hold them' for a season or two ... perhaps make a 20 by 20 nursery bed in their garden.. and simply transfer them there.. until you are set in the new place ... and can come back and get them ... because.. one sure thing i didnt realize at the time was ... after the move.. and all.. that 'taking them' was less than 25% of the job ... defining the garden.. building the beds.. and actually getting them planted.. was the bigger problem ... all the while unpacking and painting a new house.. and on top of it all .... trying to build a garden.. was rather overwhelming .... not really for the faint of heart ... in hindsight.. i would never do it again ...

and dont forget.. if you end up with 100 pots.. you are going to have to figure out how to move them all .. besides moving the house.. the kids.. etc ...

good luck ...

ken

Extra outstanding post Ken!

thanks!! .. i have typed it a hundred times.. and really have it condensed to the nut of it all.. lol ...

ken

Thank you all!! Toronto can get major freeze-thaw cycles and this makes it tricky. Our (possible) move date is unknown at this point, which doesn't help.

I think a combo of all suggestions will work and you've all given me a lot to think about and apply elsewhere.

Some of the plants have taken me a while to find (giant hyssop, red milkweed, swamp milkweed, pale pink coneflower, woodland plants like bellwort, liver leaf)... so I'm reluctant to let these go but the point about cost is a good one. Will have to make some hard choices.

Final question: I'm not clear on your collective advice about potting media. Ken, what medium/media did you wind up using?

Again, thanks!

12 years ago.. i used what was called promix 360 ...

but google fails on that.. but shows metro mix 360 ...

but at the new place ... i ended up with sunshine something or another ...

both came from the nearest high end nursery .. at each house ... and they sold me giant bags of what they used ... if you buy a DRY BAG ... it will store in a plastic garbage can for a century or two ...

peat based media comes in various coursenesses .. perhaps a new word there.. lol ..

for seed starting.. media is nearly a fine ground powder .. to retain a lot of moisture for the surface seed ...

my mix was very course.. and included vermiculite and perlite ... so as to create a very 'airy' media.. as roots need air.. as much as water .... especially in winter ...

this might make a great new post.. titled appropriately for future searching.. rather than buried down in this post ...

ken

god i hate when i forget the link.. lol ... ken

Here is a link that might be useful: flip to the search side for info ...

best advice given so far was to store at a friend's garden. In the ground is much easier on the plants, then you can dig & take to your new place when you're ready. Unless of course the distance is prohibitive. The extra assurance of divisions at a friend's home makes sense. Then there are plants in 2 places. Of course, don't divide those perennials that don't divide easily.

Alternatively you could take cuttings or layer some depending on the type. Layerings might be the easiest way unless you need the new plants right away. Then next spring dig & move.

Julie,
Welcome to our province, whenever you make your move. A bit of advice regarding your perennials....make sure they will survive this zone before digging them up and preparing them for their journey West. I have lost more perennials than I can count, but gardeners are an optimistic bunch...good luck!