The answer to 'why is my shrub drainage problems' is that poor drainage can be caused by a variety of factors, including heavy clay soil, compacted soil, or a high water table. Symptoms may include waterlogged soil, wilting or yellowing leaves, and root rot.
To address drainage issues, you can try improving soil drainage through methods like adding organic matter, installing a French drain, or aerating the soil. However, if the problem is severe or the cause is unclear, it's best to consult a professional landscaper who can diagnose the issue and recommend the appropriate solution.