Planters that do not drain properly generally do not cause a problem. However, if the planter is near the foundation of the home, then drainage becomes more important. Basically having standing water or excessively wet soil next to the homes foundation is not healthy for the foundation.
Areas with expansive soil are especially sensitive to excessive moisture. When the soil gets wet, it expands in volume. This places pressure on the foundation or slab of the home and can result in cracking of the foundation or slab. Additionally, it can lead to moist conditions developing under homes that have raised foundations.
Keeping moisture away from the foundation
Planters with drains in them need to be kept clear of debris such as leaves and roots. This maintenance duty is often overlooked because the drains are out of site or plants are covering them. Check to make sure that any covers are intact and undamaged. At times when placing plants in the planter, soil gets moved around and it ends up making it so that the drain is actually higher than the soil. Re-grading the area or lowering the drain will easily solve the elevation problem.
Does the planter height or design allow water against the homes’ wall?
If the answer is yes, then you should check to see if there is moisture getting into the wall. If so, mold or mildew may exist, which under some circumstances is a health concern.
Wood rot or deterioration can also occur if moisture is entering the wall. Should this be the case, proper maintenance or repair would be wise.
If moisture is getting into the walls of the home because of the planters, then corrective action is wise. This may include adding or improving drainage to the planter and under some circumstances, just removing the planter is easiest and best.Who to consult? Landscapers, gardeners and handymen
Many homeowners prefer to improve the drainage themselves. If busy, they often will call a gardener, landscaper or handyman.