Phacelia Green Manure Seeds

Phacelia Green Manure Seeds

Botanical Name: Phacelia tanacetifolia

Phacelia is a fast-growing annual green manure and pollinator cover crop valued for its quick establishment, fine root system, soft biomass, and highly attractive purple-blue flowers. It is commonly used to improve soil structure, suppress weeds, support beneficial insects, and add organic matter to garden beds, orchards, vineyards, paddocks, and crop rotations.

Phacelia is especially popular as an insectary plant because its flowers attract bees, hoverflies, lacewings, parasitic wasps, and other beneficial insects. It is a useful non-legume cover crop for increasing biodiversity and supporting natural pest control in vegetable gardens, orchards, market gardens, and regenerative farming systems.

• Fast-growing annual green manure and pollinator cover crop.
• Highly attractive to bees, hoverflies, lacewings, and beneficial insects.
• Produces soft biomass that can be chopped and returned to the soil.
• Fine roots help improve soil structure and protect bare ground.
• Quick canopy growth helps suppress weeds and reduce erosion.
• Useful in vegetable gardens, orchards, vineyards, paddocks, and flower strips.
• Best suited to cool, temperate, and mild subtropical conditions.

Plant Details

• Plant Type: Annual green manure, cover crop, and insectary plant
• Botanical Name: Phacelia tanacetifolia
• Growth Height: Approximately 30–90 cm depending on conditions
• Growth Habit: Upright annual with fern-like foliage and curled flower clusters
• Flower Colour: Purple-blue to lavender
• Root System: Fine fibrous roots
• Frost Tolerance: Moderate once established
• Heat Tolerance: Moderate; avoid extreme heat during establishment
• Best Position: Full sun to light shade

Best Uses

• Green manure crop
• Pollinator seed planting
• Beneficial insect habitat
• Cool-season cover crop
• Weed suppression and soil cover
• Orchard and vineyard inter-rows
• Vegetable garden rotations
• Flowering strips and insectary rows
• Regenerative farming and biodiversity plantings

Sowing Information

• Best Sowing Time: Autumn to spring in most suitable regions
• Germination Time: 7–14 days in suitable conditions
• Sowing Depth: 5–10 mm
• Position: Full sun to light shade
• Soil Type: Well-drained soil preferred; suitable for a range of garden and cropping soils
• Watering: Keep moist during germination and establishment
• Sow Where: Garden beds, orchards, vineyards, paddocks, flower strips, inter-rows, and fallow areas
• Important: Phacelia is not a legume and does not fix nitrogen, but it supports soil health, beneficial insects, and organic matter production.

Sowing Rate and Coverage

Seed Quantity Guide

Coverage is a guide only. Use higher rates for faster cover, stronger weed suppression, poor seedbeds, exposed sites, or areas with bird pressure.

When to Sow Phacelia in Australia

How to Sow Phacelia Seeds

1. Choose a sunny to lightly shaded position with well-drained soil.
2. Remove weeds and prepare a fine, firm seedbed.
3. Broadcast seed evenly or sow in rows.
4. Cover lightly with approximately 5–10 mm of soil.
5. Press or roll the surface gently for good seed-to-soil contact.
6. Water gently and keep moist until seedlings establish.
7. Allow to flower for pollinator support, or cut earlier for green manure use.

Management

• Keep soil moist during germination and early establishment.
• Cut before seed set if volunteer plants are not wanted.
• Allow flowering where pollinator and beneficial insect support is the priority.
• Cut before full maturity for softer biomass and easier breakdown.
• Leave cut material as surface mulch in no-dig systems or incorporate as green manure.
• Avoid sowing into hot, dry, or waterlogged conditions.

Harvest and Incorporation

For green manure use, cut or chop Phacelia before heavy seed set while stems are still soft. Incorporate the chopped material into the soil 2–4 weeks before planting the next crop, or leave it on the surface as mulch in no-dig systems. If the main goal is pollinator support, allow flowering before cutting.

Soil Benefits and Use

Phacelia helps improve soil by providing quick cover, fine root activity, organic matter, and biodiversity. Its canopy helps shade bare soil and reduce weed pressure, while its flowers support beneficial insects that can assist with pollination and natural pest control. It is especially valuable in mixed cover crop blends and pollinator-friendly rotations.

Important Notes

• Phacelia is not a nitrogen-fixing legume.
• It is highly attractive to bees and beneficial insects when flowering.
• Best results occur in cool to mild growing conditions with reliable moisture.
• Avoid hot, humid lowland tropical conditions.
• Cut before seed set if self-seeding is not wanted.
• Can be used alone or mixed with other green manure and cover crop species.

Quick Growing Guide