Herb cover crops

Species of cover crops other than legumes, brassicas and cereals include buckwheat, phacelia, chicory and linseed. Sometimes referred to as ‘herbs’, they are in different families to most cash crops and can be used to avoid rotational conflicts.

Common buckwheat: A summer broad-leaved annual that is easily killed by frost and best used in mixtures. It grows better than many other cover crops on low-fertility soils. It is effective at scavenging phosphate with its fine fibrous rooting system. It has also been reported to suppress some root pathogens. It proliferates and completes its life cycle quickly, taking around six weeks from planting into warm soil until the early flowering stage. It is possible to grow more than one crop per year in many regions . It can grow more than two feet tall in the month following planting and competes well with weeds. Although its seeds do not disperse widely, it can become a weed. Mow or till it before seeds develop to prevent reseeding. It should not be grazed as it can cause photosensitivity in livestock.

• Sowing (autumn): August
• Example sowing rates kg/ha (as a single species): 70

Phacelia: A fast-establishing cover crop with good top growth and a root system that suppresses weeds. A competitive crop with benefits for managing erosion, leaching and structure. Not entirely frost tolerant and unlikely to senesce fully over winter.

• Sowing (Autumn): Mid-Aug – mid-Sept
• Example sowing rates kg/ha (as a single species): 10

Chicory: Produces deep-rooted cover crop (delivering soil structure benefits) and is better suited to longer-term use, especially where grazing is of interest. It can be used in mixtures.

• Sowing (autumn): August
• Example sowing rates kg/ha (as a single species): 15

Linseed: Can perform well on challenging (thin) soils. Although not hardy, it grows well into winter, especially in a species mix. It is susceptible to flea beetle.

Note: Example sowing dates and rates (where shown) are taken from the AHDB cover crop review.