How to lime helleborus
I live on a small suburban lot which has lots of native oaks, blueberries, mountain laurel and other acid loving trees and shrubs. I have 12 helleborus plants (about 6 years old) in my back yard. I have read that they like a neutral or slightly alkaline soil. The back yard slopes slightly toward the native woods. how can I make the soil a bit more alkaline around the helleborus without hurting the acid loving plants?
A soil test will determine your soil pH. In early spring the plants will benefit from the addition of compost. The soil test will also indicate the levels of magnesium. If Mg is low you can sprinkle a hand full of Epsom salt or dolomitic lime around each plant.
Yes, I've read to apply compost, but my compost is generated mostly from oak leaves. It's great for mulching my azaleas, pieris and hydrangeas, but it's probably too acidic for the helleborus. Guess I'd better do a soil test on those locations.
Oak leaves, like almost all other organic matter with the possible exception of pine bark, will compost to a neutral pH. So, don't worry about using oak leaves mulch on your helleborus.
Lime does not dissolve and so it does not move around in the soil very much. Therefore, if you would like to apply some lime around your helleborus, simply be careful to scratch it into the soil and not leave it on the surface where it could be washed down the hill in a heavy rain.
Helleborus are tough plants and not exactly finnicky about pH (acidity or alkalinity of soil).