Not many of us are naturally blessed with a good rich loam soil that is ideal for all plants. If you have heavy clay or sandy soil you will need to add plenty of organic matter to improve the structure and widen the range of plants that will thrive.
Digging will help to improve the drainage of clay soils, but is unnecessary on loam or sandy soils. While you are digging incorporate as much bulky organic matter as you are able. Your compost heap will provide well rotted material created from vegetable peelings from the kitchen mixed with grass cuttings and other plant material such as fallen leaves, dead annual bedding and annual weeds.
If you don’t have enough material for your needs then fresh bags of Organic Blend Soil Conditioner or Organic Blend Farmyard Manure bought from your gardening retailer will provide unlimited supplies. Remember to dig in any compost from spent growing bags, patio pots and hanging baskets once they are finished.
Improving heavy clay soil
Usually cold, wet and sticky for most of the year but in dry weather cracks appear or the surface cakes over. Holds a lot of moisture and plant foods that are not leached away by rain.
Dig any unplanted areas in early autumn and add a generous amount of organic matter as you go. Leave the clods rough so that frost can break down the structure. A dressing of gypsum will also help in this process of producing a crumb structure. Repeat the process each autumn to help produce a crumbly textured soil.
Soil in between plants can be gradually improved if bulky organic matter is forked into the top 15cm of soil each autumn. A mulch layer of material applied each spring around established plants will also help improve the structure and the amount of worm and micro-organism activity.
Improving light sandy soils
Thin soil short of nutrients quickly drains moisture so watering is needed frequently during summer. Plants are naturally shallow rooted. Digging won’t help, but adding bulky organic matter in spring will. Use plenty of farmyard manure, garden compost or organic soil conditioner when planting to give moisture-holding material at root level. Mulch all over in late spring to reduce evaporation and use ground-cover plants to shield the soil.