Transplant a large hibiscus bush
Thank you for the question. There are tropical and hardy, perennial hibiscus. Since you live in Minnesota and it sounds like this shrub has been growing outdoors for several years, you must have a hardy hibiscus. Transplanting this perennial is best accomplished in the spring, once the soil is workable. Cut back the dead growth from last season and carefully dig up the roots. A 5 foot tall shrub will probably have some big roots so be prepared for some hard work. If you are moving this spring, dig it up and take to the new place and plant right away. Be sure to choose a location with full sun and adequately drained, rich soil. Water well the first year until well established. Typically, hardy hibiscus don't require much intervention after the first year.
Since I don't know when you are moving, the general advice is that while spring is best for transplanting hardy hibiscus, you can transplant perennials until quite late in the season as long as you water well until the ground freezes, but the later you transplant, the less likely the plant is to make it through the winter. Ideally, the plant needs a few months to grow some roots before winter for best success next season.
Read more about hardy hibiscus in this publication from Illinois Extension: http://web.extension.illinois.edu/dmp/palette/090712.html
This publication on planting and transplanting perennials, also from Illinois Extension, provides good general information:
Thank you for contacting Extension.