I wouldn't dig them up until late summer/early fall when the weather is cooler. If you have enough space around them to dig and they're not huge, old plants then I would move them. You could always get some insurance by taking cuttings (Weigela are easy to root) or layering before you dig them up.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize that we can't eat money. Cree proverb
