Because the foundation cement can leech lime into the soil and make the soil alkaline, it would be best to plant the shrub a few feet away from the house. If the house foundation is old, it may no longer leech lots of lime so then it would not matter if you planted it close (provided you still regularly amended the soil some).

I placed some camellias about 2 ft from the house and the prev owner had some hydrangeas closer to the foundation. The hydrangeas require that I amend the soil in the Spring and (only sometimes) again in mid-summer. The camellias have not had any issues. An Annabelle that I planted about 1 ft away from the foundation has not complained; I amend its soil only once a year but it is relativel;y speaking new shrub.

The thing with the paniculatas is that they can get huge depending on the variety so they may generate more roots towards the foundation and may require that you amend the soil once or twice. It obviously would help if your soil was already acidic as hydrangeas will tolerate alkalinity up to a point without showing too many issues. Meaning that the leaves, for example, may not be dark green but "almost" dark green and may not show the leaf veins darker than the rest of the leaf (a common iron chlorosis symptom).

Luis

This post was edited by luis_pr on Sun, Mar 10, 13 at 10:51