My Wine & Roses Weigela shrubs are leafing out only about 5 % throughout the shrubs. They have been established for about 9 years on the south side of the house. A friend in my community is also having the same problem. I’m enclosing a photo. As you can see they are not leafing out just at the bottom, but there’s a few leaves throughout the shrub. Should we wait awhile to see if more leaf out or should we trim them back to about 1 foot from the ground? Sure would hate to lose them! Barb
There are a few things to consider with Weigelas. It is not uncommon for them to show dieback. Last year we had a sudden hard freeze, which could have injured some wood, so for now, just wait. It is really still early for some plants.
Weigelas do benefit from a good pruning to encourage more new wood, especially after 3 years or so. Since your shrub has been in the ground for nine years, I'd recommend pruning it. First the dead wood (after you see what has survived), then again after it blooms. If you find that most of the top wood is dead, then, yes, prune it way back to rejuvenate. Although Weigelas bloom on old wood, they can throw off a few more flowers later in the season on new growth.
Here is the link to the KSU bulletin on shrub pruning: http://www.ksre.ksu.edu/bookstore/pubs/mf2998.pdf .And here is a the link to a more detailed KSU bulletin on pruning both trees and shrubs: http://www.ksre.ksu.edu/bookstore/pubs/c550.pdf . Both have good illustrations to guide you.
Weigelas like a sunny location, so it sounds like yours is in a good spot.
Carole-Johnson County Extension Master Gardener