Hello, I am in the process of replanting/revamping my entire front garden and I need to add more soil to bring it up to the level of the retaining wall. The soil right now is about 6 or 8 inches lower than the top of the wall. In the corner is a large bridal wreath spirea. My concern is if I add more soil to the base of the spirea will it harm the plant.
How much earth is recommended to put on top of the root area of a shrub? For example, if just smoothing away some soil from a nearby new planting, maybe 2 inches of it... Never add any? What about mulch, is it considered much more breathable and less apt to smother the root area? Mulch is so commonly added over everything...
For a bridal Wreath Spirea you can add up to a foot of new soil around the base of the plant (of it is a mature 4 -5 foot tall specimen) with out much harm. Just remove as many leaves from the base of the plant that will become covered in soil (the leafs can cause issues as they rot under the new soil around the base of the plant) After being covered the plant may even form extra roots in this area. This is not always the case for every tree or shrub (in fact in the case of tree's it is usually an exception) Best of luck
