I live in Lynchburg, VA and was wondering whether spring or fall is a good time to plant, and what kind of soil to use. Thank you.
Crape myrtles need a sunny location and well drained soil. It is not fussy about soil and is adaptable to many soil types. No need to amend the soil.
Fall is the best time to plant trees and shrubs, however often spring has the best selection in nurseries.
https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-care.htm
Our weather is mild. Freezing doesn't last over a couple of days.
Your crape myrtles shouldn't die in zones 7b and 8a, which you are. The worst scenario if you had unusually cold weather would be if they died back to the ground and came back from the roots. I live in zone 6 and crape myrtles are everywhere.
Here are growing tips:
https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-care.htm
We just purchase a home where there is a Crepe Myrtle that is about 30' high and hanging over the house. I really want it off the house but don't want to kill it. Bottom line is I would like to have it more manageable. Thank You for any suggestions Mark Klosek
Crape Myrtles benefit from very hard pruning every year, or every few years. You can cut back to any height that you choose, either after the flowers drop or during dormancy.
This article will help: https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/pruning-crepe-myrtle-trees.htm
How wide should make the base on the ground to hold the water? I transplanted a medium sized tree last year in Feb. when it had no leaves. It sprouted all new leaves but never really grew. Now all the leaves are brown and it appears to be dying. How do I know it is still alive?
You can tell if it is still alive by breaking off the tip of a branch and looking for green inside. Or just scrape off the outside layer of a stem and look for green inside.
It may have been planted too deeply during the move. Crape myrtles usually decline if they are not planted level with the nursery container, or in your case, the same height it was in the ground.
https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-tree-problems.htm
Got rid of crepe, pulled out roots- no stump was there. Getting suckers. If I put table salt or vinegar and cover with black plastic, will that stop suckers from growing?
Salt should work, but you won't be able to replant in the area for quite a while. An herbicide might be your best bet. Be sure to follow label instructions.
I wouldn't worry about the roots being invasive. This article will explain: https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-root-system.htm
You will be limited by the size of the shrub you choose. Many will get to between 5 and 10 feet wide. If you are planting at least 10 feet away, then you can be sure that it will not obstruct the road.
Here is an article that will help you with the care of the shrub: https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-care.htm
I'm not seeing the missing portion of the article. It states to prune during dormancy, which will be different depending on where you live. Just in case you found a different article than the one that I am using- Here is that article: https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/best-crepe-myrtle-pruning-time-when-to-prune-crepe-myrtle.htm