Changing a alkaline or chalk soil to extend the type of plants you can grow

Lowering the soil pH in a alkaline soil to suit more plants 

As simple as it sounds adding acid will lower the soil pH in an alkaline or chalky soil 

The acid can come from a number of acidic sources such as 

Farm yard manure – ideally well rotted unless the area or flower bed is empty it needs to be well rotted. Fresh manure can burn the roots of any existing plants.

Horse manure – ideally well rotted unless the area or flower bed is empty it needs to be well rotted. Fresh manure can burn the roots of any existing plants.

With both types of manure its important not to import any weeds that might be growing on and around the manure pile or stack. Ideally taking the manure from the middle of the pile or stack as often the manure will have heated up and killed and existing weeds or weed seeds. 

Chemical solutions include flowers of sulphur, sulphur dust, iron sulphate

All these are best dug into the soil and allowed to be washed in by rain or watering takes place 

A combination of chemical treatments and manure are ideal with annual treatments and mulches 

To a lesser extend using such fertilisers as Growmore annually will also help lower the soil pH