Burying indoor perennials over the winter?

I'm growing Balloon Flower and Columbines indoors, and was told I would need to take them outside and bury them through the winter.

I figured keeping them inside would keep them healthy all year even if they only flower in season. Can anyone explain if this is true and if so, why it's necessary?

I'm in Zone 5b by the way.

Someone was trying to impress upon you that the plant NEEDS a cold rest, and offered good information. Most, but not all temperate deciduous plants need a cold rest in the winter to grow well in the subsequent growth period. Your plants DO. Cold dormancy also has a very large influence over bloom set and subsequent fruiting. Also, deprived of a dormancy, it's not unusual for a plant to grow weakly before simply shedding its foliage and going dormant during the middle of the next growth cycle, often in the middle of summer. This is always fatal unless you recognize it for what it is and give the plant sufficient chilling until the following spring.

Burying the plants on the north side of a building out of direct sun is a good strategy, but you can also over-winter in an unheated garage. In both cases, you'll need to ensure that the soil never dries completely, but you don't want it to be soggy, either.

Good luck.

Al

Thank you muchly Al!

A cold rest is much better than having to replant twice. I can just put my planters outside. I had better check that they're hardy though since I'm in an apartment and don't have a garage. Although the storage rooms might be cool enough.

Cool enough = a consistent temp for both plants from 25* to about 42* (-4 to about 6*, for you).

Al

But if they were planted outside, they'd be getting the full coldness of the winter at -25C. How could they survive that?

The info pages say they're hardy to zone 3 (-40 for both of us). So being outside in planters for that time, would that be any different than outside in the ground?

6" soil temperatures in bare farm fields in your zone rarely see 25*, no matter how deep the frost goes. The earth is a great source of geothermal heat that moderates root temperatures. Once you put a plant in a container and expose the sides to the full effect of winter chill, and especially if you isolate it from the ground (and the effects of geothermal heat), root temperature quickly equalize with ambient air temps ....... and you have an OOPS moment. ;o)

It's also important to keep in mind that all roots (on the same plant) don't have equal hardiness. Just because a plant will live through root temps of 20* and lower, is no clear indication it likes it. The finest roots die first, usually at quite high temperatures (25-32* in most temperate plants, leaving only large roots that are of little value, except as conductive tissue. The result is, you often essentially start spring with a near dead plant or very close to a cutting, waiting for roots to regenerate so the plant can move water. This is very taxing from the perspective of energy outlay. .... beginning to see why we have a vested interest in preventing roots from freezing, or at least reaching killing lows, instead of seeing how much cold a plant can tolerate? ;-)

Al

Ah I see. There is so so so much to learn about gardening!

I'll have to think of something creative come the winter then if my building's storage area isn't cold enough. Something to keep in mind as I decide where to put things this year.

Thanks very much for the info.

You're most welcome.

Al