Not quite sure how to handle this etiquette-wise but I think it merits a new thread, perhaps best without pointing fingers or naming names. On two recent threads a difference of opinion has arisen regarding the advisability of moving plants, especially woody ones, at this time of year. It seems accepted that fall is planting time for potted plants, but someone recently said that moving plants is NOT advised at present because it is bad to disturb roots until they are dormant. The opposite point of view is obviously that fall is a fine time to move plants as well as to plant them as roots are establishing themselves and can thus recover from the trauma of moving. I've also heard that in climates that have serious winters, plants need a certain amount of time to get established prior to freeze-up. Can anyone come to this debate with some solid information to round out the opinions aired so far?
It's ok to transplant things in the fall if it's early enough in the fall and in a relatively mild location (i.e. Vancouver vs N. Ontario) so that there is still time for it to re establish itself (e.g. 6 wks) before serious frost. Or else a late fall transplant with a large rootball (thus not requiring much re-establishment) once a plant or tree is dormant is ok too. Problems arise when plants with actively growing roots and foliage are put in the ground late with no way to anchor themselves well, or adapt to existing soil conditions, etc. There's no one all-purpose answer, just a combination of things to balance out. Putting a 5-10 yr old nursery grown tree with a large rootball into your garden at almost anytime will not be as risky as a young actively growing plant with lots of foliage still on it into a new environment just before things are scheduled to freeze up (or at least come close to it). And it would be quite risky to prune roots at that time as well, as new roots would be stimulated into growth, only to be cut down by the cold before having a chance to harden off.
I would add my 2 cents- Even here in the mild winter Pacific Northwest, fall transplanting has its limits. I feel comfortable transplanting deciduous woody plants right through October and into November; our soils stay warm through December, there is usually good moisture in them, and rarely do our soils freeze more than just at the surface, so roots can continue to grow even as the tops are dormant. Transplanting evergreens, however, is different, and their foliage continues to transpire moisture right through the winter. The gamble lies in the winter weather; will it just be cold and rainy, or will we get one of those famous Fraser Valley outflow blasts? I have transplanted evergreens late in November, only to be blasted in December by a NE cold wind, which burnt the foliage severely. The plants recovered, but it took a few years. We now limit late fall transplanting to deciduous plants only, and have never had damage on those.
I think what confused me was the statement that it would be BETTER to move the plant once it is dormant in winter than to do it in fall when it still has some time to establish, and indeed this advice was given to apply to deciduous plants. This GW thread happens to discuss the issue as well: http://forums.gardenweb.com/forums/load/conif/msg1012050827635.html?5
