My front garden is south facing and very exposed to the wind. The soil is acidic, but very peaty which tends to dry out quickly. I want to put either farmyard manure, top soil or bark to retain the moisture but I need to keep the ph of the soil below 7 as I have a number of acid loving plants. All three products I will be buying in the local garden centre. Is there any of those products that you would recommend or is there another product which would be more suitable?