Handling Silt Soil

The main problem with a silt soil, as with clay, is one of drainage. Of all the soils formed by grinding, silt has the smallest particles. Only the particles of clay are smaller, but they were formed by chemical action. The size of the particles means that they tend to pack together very closely when wet, preventing the free passage of water and air through the soil.

So drainage is poor and there is a danger of the soil settling down to form an airless mass. However, if you never walk on the soil when it is wet (use boards) and condition it as recommended here, silt is perfectly manageable and will produce satisfactory results.

Digging

Silt soil should be cultivated only when it is dry enough not to stick to your boots. Conditions underfoot permitting, aim to dig silt during the fall to take advantage of weather which will help break the soil down to a sowable tillage. Like clay, when silt gets wet and dries out again, it expands and contracts, causing the mass of soil to crack into small clods.

If water then gets into these cracks and freezes, it will force them further apart, breaking the soil down even more. So by digging silt over in the fall, you expose the maximum amount of the soil surface to the elements and work the organic material into the topsoil at the same time.

Drainage

In order to improve drainage, the soil particles have to be forced apart physically to allow free passage of air, water, and plant roots. Do this by digging one or two bucketfuls of coarse sand into the soil every square yard/meter when you dig in the organic matter. Raising your ornamental beds slightly and growing vegetables on the deep bed system will improve drainage, helping the soil dry out and warm up.

Organic Matter

The structure of silt soils benefits greatly from the addition of liberal quantities of well-rotted compost or manure. Adding plenty of bulky organic matter to the soil will hold the particles apart so that roots and water can pass through more easily. If possible, keep the soil covered with a green-manure crop in order to add organic matter and remove surface water.