Hi Catherine. The best way to improve a heavy clay soil is by adding clay breaker and compost to your soil. Clay breaker can by bought by the bag from hardware shops and isn"t very expensive. It forms a chemical reaction with the soil to change the texture. If you start a compost heap with lawn clippings and other garden prunings you could make your own compost to add to the clay to improve it. Cow manure will also help and can be bought by the bag. Not many plants will grow well in unimproved clay so it is worth spending time first improving it. Some suggestions for shrubs for shade once the soil is improved include Mackaya bella, Euonymus cultivars, Abutilon, Megaskepasma, Strobilanthes species, Plectranthus species and cultivars. These plants can all be seen on my Plant Reference feature on this website. Deirdre

 Thanks, Deirdre. :-)

 Hi Catherine, don"t forget that simple tree mulch from a local Tree Contractor is also a fantastic source of organic material, you can put the mulch on green and then nature do it"s magic, "Horizontal Composting". Remember, mulch feeds your soil, not the plant.