Vegetative Growth
Flowering Plant



(Phacelia tanacetifolia)

Phacelia is a rapidly growing, high biomass plant. It is a nitrogen holder and weed suppressor. Its eye catching purple flowers are particularly good at attracting bees and other beneficial insects.


Used as a soil improving green manure.


An annual species.


Phacelia is effective at preventing nitrogen leaching and suppressing weeds, due to its fast establishment. Although not known as a deep rooted species, its dense zone of shallow roots are very good at conditioning the top 3-4cm of soil. Itís a good source of pollen and nectar for pollinators and other beneficals.

Frost Tolerance

Phacelia may survive through very mild winters, however prolonged frost will normally kill the plant.


2 - 3t DM per ha.

Sowing Rate Advice

4kg per acre / 10kg per ha.

The seed of phacelia is very small, so it should be shallow sown, pure stands may become open later in the winter.

Mixture Sowing Rate Advice

0.25kgs - 0.5kgs per acre / 0.625 - 1.25kgs per ha

The vigorous nature of phacelia means it should not be used excessively in mixtures with slower growing species.

Ideal Sowing Time

As itís a quick to establish species, sow from spring until autumn after the risk of frost has passed.


Phacelia does not need topping and is generally free from problems with pest and disease. Phacelia can flower and set seed quickly, if seed shed is a risk, destroy at or just after flowering.

Distinguishing characteristics


This is a particularly small and light weight seed, with an orange segment type shape. It is a uniform, dark brown cover and a coarse texture. The seed is 2mm in size.


The seedling develops a pair of rounded, lance shaped, broad cotyledons. They are several times longer than their width, with a mid vein and short to medium stipules. The first true leaf is feathery with deeply divided, lobed leaflets.

Vegetative State

Flowering Plant

Flowering Plant
This is an upright and multi branched, dark green and hairy plant. The leaves are deeply divided, with leaflets cut into small lobes giving them a feathery appearance. The inflorescence is eye catching, lavender to pale blue or white in colour, with pronounced hair like stamens. The root is shallow, with many dense, lateral side roots.

Additional Info

The seeds will only germinate in darkness, which means they should be shallow sown or harrowed and rolled well after sowing. Biomass production is prolific above ground but breaks down quickly after mulching as much of the canopy comprises a fine leaf structure, this may be a positive trait for direct drilling systems.

Works well with

It can be combined in mixture with other fast establishing species like mustard, the annual clovers or buckwheat.

Buy Phacelia Straight

You can find Phacelia in the following mixtures