By Schieftain
United States 
How far do Weigela roots grow?
9 Aug, 2013
Answers
The fine feeder roots can actually go much further, but are nothing to worry about, in practical terms.
11 Aug, 2013
as a rule the amount of roots tend to match the amount of top growth. When I removed a 20 yr old one the main roots went down for about 5ft and spread a good 6ft in all directions.
9 Aug, 2013