We have touched on the subject before, but I wanted to take a minute and reiterate my opinion and experience on when to transplant most plants. This may or may not apply to the extreme cold climates because the ground temperature gets so cold, but this works extremely well for zones 5 and up. If you don’t know what zone you are in, check out this link.
Typically following a good frost, plants begin going into their winter dormancy period. How do they go into dormancy you might be asking. Well, the sap that is their ‘blood’ begins to leave the top of the plant and the branches prepare themselves for the cold weather. This is why Deciduous trees loose their leaves in the winter.
Once the plants go dormant, they are not actively growing and will begin to concentrate on strengthening their root systems during the winter. This means that if you want to move a plant, do it anytime after the first hard freeze. With the plant going into dormancy, they will not realize they got moved and will repair its root system before the growing season in the spring.
This is a very simple concept that if carefully utilized, can save you from having to replace plants after transplanting. Anything I can do to help us in the recession to save money!!