The Red Prince weigela becomes an upright deciduous shrub with medium green leaves and bell-shaped red flowers in early summer. This variety's key features include flowers that do not fade their red color in intense sunlight as well as producing a small flowering display again in late summer. Plant Red Prince weigela in a fertile, moist, well-draining soil in at least six hours of daily sunshine in U.S. Department of Agriculture hardiness zones 4 through 8. It slowly grows to a mature height of 5 to 6 feet and 4 to 5 feet wide.
Remove dead or diseased branches of the Red Prince weigela with a hand pruners. Make the pruning cut 1/4-inch above a lower healthy branch junction or stem to fully remove the dead or disease-ridden branch. Consider spraying the pruning blade with rubbing alcohol if it was a diseased branch and you plan on making more pruning cuts on other healthy plants.
Cut the majority of main branches back by one-third their length across the entire shrub after flowering display of Red Prince weigela wanes by midsummer. Make all pruning cuts 1/4-inch above a lower branch junction, healthy leaf or dormant bud. Feel free to slightly stagger the heights of cuts across the shrub so it does not look like a sheering ball when your summer pruning task is done.
Allow new growth to sprout back from the midsummer pruning. You can remove any dead or diseased branches, but do no further pruning of the weigela shrub the rest of the year.
Tip prune any errant branches after winter ends to remove any dead or diseased plant tissues. Do not prune large parts of the shrub as removing alive, healthy stems in late winter and spring reduces the flowering due in early summer.