Answer: Moving any plant that has been established in the same spot for 20 years will be risky, but I think you can do it. The very best time to move your roses is in winter when they are dormant. They will suffer lots less stress if they are sleeping when you dig and replant them. Start by cutting them back to a manageable size (not too severely, about a third of the plant can be safely removed). Expect the root system to be extensive so try not to sever too many of the largest roots. After replanting water them well and water every 10-14 days during the winter months unless natural rainfall takes over. You should see some new growth in the spring and it will probably take the shrubs a full season to become fully established in their new homes.
If you must move them now (in spring) follow the above directions but water them deeply once each week during the growing season. They'll probably drop their leaves an look pathetic for a while but eventually they should start putting out new growth.
Best wishes with your move!
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