Phacelia Green Manure Seed

Phacelia is a fast growing, hardy annual green manure that establishes quickly and produces dense foliage. Its shallow but extensive root system helps to improve soil structure, while the leafy growth is effective at suppressing weeds. It is suitable for most soil types and performs particularly well in dry conditions.

Although phacelia does not fix nitrogen, it is an efficient nitrogen holder, taking up nutrients and returning them to the soil when dug in. It fits easily into crop rotations and can be grown before most crops.

Phacelia should be sown between March and September and grows rapidly, reaching flowering stage within six to eight weeks. To prevent self seeding and to gain the greatest soil benefit, it should be cut down and dug into the soil before flowering.

How to sow

Dig the soil and remove weeds. Firm the surface by treading lightly, then broadcast the seed evenly. Rake over the soil and water well. Germination is quick, even in cooler conditions.

How to dig in

Chop the green manure into small pieces using a spade and turn it into the top 10 to 12cm of soil. Alternatively, cut it down and leave the clippings on the surface, covering them to exclude light using cardboard and grass cuttings or a biodegradable ground cover. Leave for at least six weeks, allowing the material to break down naturally and be incorporated into the soil by earthworms.

To sow as a pollinator-friendly wildflower

Phacelia produces masses of nectar rich purple blue flowers that are highly attractive to bees, hoverflies and other beneficial insects. When grown for pollinators, allow the plants to flower fully and avoid cutting them back until flowering has finished. A small patch can be sown near vegetable crops to help attract pollinating insects into the growing area.