Nitrogen Fix Mix Green Manure Seeds

Nitrogen Fix Green Manure Seed Mix

Botanical Names: Crotalaria juncea (Sunn Hemp), Helianthus annuus (Sunflower), Vigna unguiculata (Cowpea), Lablab purpureus (Lablab)

Nitrogen Fix Mix is a warm-season green manure and cover crop blend designed to build soil fertility, add organic matter, suppress weeds, and improve soil structure during the warmer months. This high-biomass mix combines nitrogen-fixing legumes with deep-rooted sunflower to create strong seasonal growth and useful chop-and-drop material.

Sunn Hemp, Cowpea, and Lablab support nitrogen fixation when compatible rhizobia are present, while Sunflower adds deep roots, upright biomass, and pollinator value. This mix is suitable for vegetable gardens, orchards, food forests, paddocks, fallow blocks, market gardens, and regenerative farming systems.

• Warm-season green manure mix for nitrogen fixation and soil improvement.
• Includes Sunn Hemp, Cowpea, and Lablab for legume-based soil fertility.
• Sunflower adds deep roots, biomass, and pollinator support.
• Fast canopy growth helps suppress weeds and protect bare soil.
• Produces organic matter for chop-and-drop mulch or soil incorporation.
• Suitable for gardens, orchards, paddocks, broadacre rotations, and regenerative systems.
• Best grown in warm, frost-free conditions with reliable moisture.

Plant Details

• Mix Type: Warm-season multi-species green manure and cover crop blend
• Main Uses: Nitrogen fixation, organic matter, biomass, weed suppression, soil conditioning, and pollinator support
• Growth Habit: Mixed legumes and upright broadleaf species
• Root Benefits: Combines legume roots with deep sunflower roots for soil structure and nutrient cycling
• Best Position: Full sun
• Frost Tolerance: Low; this is a warm-season mix
• Coverage: Approx. 100–200 m² per kg depending on sowing rate and conditions

Best Uses

• Warm-season green manure
• Nitrogen-fixing cover crop
• Summer soil improvement
• Organic matter production
• Weed suppression and bare soil protection
• Vegetable garden rotations
• Orchard and food forest inter-rows
• Paddock and broadacre cover cropping
• Regenerative farming and soil-building programs

Mix Benefits

Sowing Information

• Best Sowing Time: Spring to summer once soil is warm and frost risk has passed
• Germination Time: Approximately 5–14 days depending on species, soil temperature, and moisture
• Sowing Depth: 15–30 mm; cover larger seeds well and avoid burying too deeply
• Position: Full sun for maximum biomass and nitrogen fixation
• Soil Type: Suitable for a range of soils; performs best in well-drained soil with good seed-to-soil contact
• Watering: Keep soil moist during germination and establishment
• Sow Where: Garden beds, paddocks, fallow blocks, orchards, food forests, inter-rows, and broadacre rotations
• Inoculation: Legume components may benefit from suitable cowpea/lablab/sunn hemp inoculant for stronger nitrogen fixation.

Sowing Rate and Coverage

Seed Quantity Guide

Coverage is a guide only. Use higher sowing rates for faster canopy closure, stronger weed suppression, poor soil, exposed sites, dry conditions, or areas with bird pressure.

When to Sow Nitrogen Fix Mix in Australia

How to Sow Nitrogen Fix Green Manure Mix

1. Choose a sunny position with warm, well-drained soil.
2. Remove weeds and prepare a firm seedbed.
3. Broadcast seed evenly at the recommended sowing rate.
4. Cover seed with approximately 15–30 mm of soil.
5. Press or roll the soil surface gently for good seed-to-soil contact.
6. Water well after sowing if soil moisture is low.
7. Keep moist until seedlings are established.
8. Allow the mix to grow until useful biomass is produced, then chop and incorporate or leave as mulch.

Management

• Keep soil moist during germination and early growth.
• Use suitable inoculant where nitrogen fixation is a priority.
• Cut before heavy seed set if self-seeding is not wanted.
• Chop at early flowering for a balance of nitrogen, biomass, and easier breakdown.
• Leave chopped material as surface mulch in no-dig systems.
• Allow 3–6 weeks for residues to break down before planting sensitive seedlings.

Harvest and Incorporation

For green manure use, mow, slash, or flail the mix when the legumes begin flowering or when good biomass has developed. Incorporate the chopped material into the soil 3–6 weeks before planting the next crop, or leave it on the soil surface as mulch in no-dig systems. Cutting earlier produces softer material that breaks down faster, while later cutting produces more bulk and longer-lasting mulch.

Soil Benefits and Use

Nitrogen Fix Mix is designed to support soil fertility through legume nitrogen fixation, fast biomass production, deep rooting, and living ground cover. The mix helps protect bare soil, feed soil biology, improve organic matter, suppress weeds, and recycle nutrients during warm growing periods.

Important Notes

• This is a warm-season mix and should be sown after frost risk has passed.
• Nitrogen fixation is strongest when compatible rhizobia are present in the soil or applied as inoculant.
• Species performance will vary depending on climate, rainfall, soil type, sowing time, and management.
• Cut before seed set if volunteer plants are not wanted.
• Use higher sowing rates where fast cover and weed suppression are priorities.
• If used as forage, manage carefully and confirm suitability for your livestock and growth stage.

Quick Growing Guide