Very early spring before any growth begins is probably best, but it's usually successful to transplant around Dec. 1 after hard freezes have stopped all growth. In fall/early winter you are less busy and the soil can be in better condition for working. I usually remove the leaves if any seem to be still functioning. However, if you should have unseasonably warm weather in December, the transplanted rose may try to grow out, to its detriment.

Growing only one foot in two years suggests there may be something more wrong than lack of sunlight (pH? watering?).

I don't know if there is any best time, but I always think it is late winter/very early spring while the plant is still dormant--and doesn't know it is being moved. At least that is when I prefer to do that in my Zone 6 (midwest)--but I must confess to transplanting a couple roses this past midsummer in 90 degree heat. They moved fine and are happy, so maybe the "when" doesn't make that much difference. Not sure why, but I've never had much confidence in fall transplanting, however--I'd be afraid that the roots would not have settled in and started growing enough to get the rose through the cold winter storms.

I'd say, make sure the plant is well-watered the day before--easier to dig up and move. And have the other hole already dug so that you can slip the transplant right in.

Good luck.

Kate

Most roses/rootstocks have coarse fleshy roots and then very fine feeder roots which tend to break in transplanting. It is hard to get a solid root ball. Problems in transplanting occur when the few remaining fine roots cannot supply enough water to replace the water lost through leaves, so that the plant wilts or can even die of dehydration.

If the plant is dormant or leafless when transplanted, there will be hardly any moisture loss. The coarse roots will generate new feeder roots when the soil temperature is above 40. When the plant senses it is well supplied with moisture, and conditions are warm enough, it will produce new leaves. This new growth (roots and leaves) is fueled by energy (carbs) stored in the canes and fleshy roots. This stored energy is quite limited, so you don't want the new growth coming out on the verge of winter when it will be killed and the plant will be left depleted of energy. Ideally, when transplanting in late fall, you want the plant to remain dormant until March or April.

So the things to guard against are (a) dehydration in summer and (b) unwanted growth in late fall or winter.

But it's true that skilled gardeners can transplant just about any time the ground isn't frozen.

I'd wait for early spring. I don't like to disturb anything just before winter sets in. In the spring when it starts to show some fattening of the leaf buds is when I do mine. It's beginning to wake and you can move it and it will then establish and begin to grow right away in it's new spot.

While mounding with soil is a good idea, I find it more practical to wrap roses with burlap for the winter. Unlike soil, it doesn't freeze solid in our climate, so it can be added whenever the rose isn't covered with snow. A snow covered rose IS protected from winter and doesn't need any extra help.

I have done it all times of the year, however I have had the best luck doing it in late winter when the rose is dormant. When I've done it in summer, I get a leaf droop that can last a few days up to a week or two.