my extensive collection of Hibiscus just about died last winter
My extensive collection of Hibiscus just about died last winter due to the extreme cold in Dallas, TX. I had them in greenhouses with light and heat, but clearly not enough. The leaves are slowly coming back at the base on the large trees, some 6-7 ft. Should I cut back the trees to the new growth or will it slowly come back on the branches? Some trees are getting leaves higher up now, but it is limited.
I would cut back all the branches. Leaves will gradually come back on the branches that are not dead, but it will take a long time. Pruning often encourages plants to put out a new flush of growth. Here's some general information on pruning hibiscus. https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/tips-for-pruning-hibiscus-plants-when-to-prune-hibiscus.htm