I have an evergreen and large weigela bush in my backyard. The evergreen is about 5 feet high (I think it’s a yew). It looks terrible and I want to remove it… How do I deal with the roots? The weigela is very large but has been doing more and more poorly. It seems to be dying back and I break off many dead branches. It is about 7 feet high. I would like to save the weigela. What do I do? If it needs to be removed, there is the issue of the many roots that are under it. What is done with roots if you want to plant a new bush in that area? (photo attached, weigela back left)
Unfortunately, its rather hard to determine, in the photo, exactly what is happening with the two shrubs you mention in your request.
The weigela could do with some pruning judging by your description and the photo. Pruning helps to maintain an attractive shape and develop more vigorous growth. Its far better to make clean cuts with well maintained pruning tools rather than break off branches which may then let in disease. Early summer, immediately after flowering is the best time to prune. Firstly, cut out any dead, dangerous, damaged or diseased branches. Then, shorten stems that have flowered by 1/3rd. Also, cut back overlong and badly placed branches to the base of the plant. Never prune more than 1/3rd of the whole plant though. This process can be repeated on subsequent years until you have brought the shrub back to the size you want. It should also give this plant a new lease on life.
If you wish to remove the evergreen (possible yew) it will require a lot of manual labour. Dead or unwanted evergreens can be difficult to remove even if the plants are only small shrubs. Evergreens often send down deep taproots as well as long horizontal feeder roots. The resinous wood decays slowly and remains limber and strong even long after the plant dies.
Should you wish to tackle this yourself, first cut back all the branches to within 6ins of the base. Dig around the root ball approximately to the drip line and at least 12ins deep. The spade should sever the roots. Water the soil beforehand to make the digging easier. Angle the spade toward the middle of the shrub and slowly work the shrub up and down all the way around to loosen the soil. Eventually, you should be able to work it out of the ground. You may need to tug on the trunk to lift it out of the ground. If the root ball is 4ft or more, most likely it will be too difficult to manage on your own. This may be a project that lasts several weeks as you do not want to injure your back.
If it proves to be too much, then call in a professional.