This can be used at anytime but it is best to dress the soil in autumn and spring. Lime "sweetens" sour, acid soils, helps to raise the soil pH which helps to release nutrients to plants, improves the soils condition and helps to obtain a better tilth and drainage. It can be use on most plants except:- blueberries, azaleas, heathers, primulas, lupins and rhododendrons.
Apply at the following rate:-
Light or sandy soil 8oz per square yard
Medium or silty soil 12oz
Heavy or clay soil 16oz
As a wise precaution, keep all garden fertilisers or chemicals, stored in the well labelled boxes (preferably their original one) or containers and in a safe and secure place well away from children or others.