The BEST time to transplant anything is during it's dormant state. For
roses, that would be about 6 weeks before your last frost date. Amend the
new planting hole with as much organic matter as you can lay your hands on
and get as much of the root ball of the rose as you can, and it's doubtful
that the rose will even know it's been moved. You can prune the canes back,
just as you would for the annual spring pruning anyway, if you need to make
the shrub more easy to handle.
OTOH, roses can actually be moved most any time of the year, including
summer, if you are willing to provide *plenty* of moisture and some shade to
the newly transplanted shrub. If this is done during the hot months, you
can expect some cane dieback. Wait until the extent of the dieback is known
before pruning it off. New leaves will develop fine as long as the canes
remain green. As long as the rose has at least 6 weeks before the first
frost, fall transplanting is fine for zones 6+. The imminance of cold
weather, and the harshness of it, makes spring transplanting more advisable
in the cooler climates.
Sunflower
I also have some roses I want to move. They are pretty badly infested with
black spot. Is there anything special I can do to prevent the black spot
from affecting them in their new location?
thanks
Black Spot spores are everywhere. All you can do is follow previous
postings on the subject and practice good cultural practices in the garden.
A dormant season spray of lime-sulpher may help some. It may also be
necessary to apply a *preventative* fungicidal spray. BS cannot be cured,
only prevented.
Sunflower