Nasturtium Edible Flower Seeds

For the most reliable establishment, direct sow Nasturtium seeds where the plants are to grow. They can also be started in individual pots where an earlier crop is required.

Sowing Method

To direct sow:

1. Choose a sunny, well-drained growing position.
2. Prepare the soil and remove competing weeds.
3. Water dry soil before sowing.
4. Sow seeds approximately 10–15mm deep.
5. Cover with fine soil and gently firm the surface.
6. Water carefully.
7. Keep the soil consistently moist until seedlings establish.
8. Thin seedlings once growing strongly.
9. Maintain approximately 25–30cm between established plants.

If raising seedlings:

1. Use individual cells or small pots where practical.
2. Fill with free-draining seed-raising mix.
3. Sow one seed approximately 10–15mm deep.
4. Water gently.
5. Maintain even moisture.
6. Transplant carefully once conditions are suitable.
7. Minimise root disturbance during transplanting.

Optional Seed Soaking

Pre-soaking is optional rather than essential.

If desired:

1. Place the seeds in clean water.
2. Soak for approximately 8–12 hours.
3. Drain before sowing.
4. Do not leave the seed soaking for prolonged periods.

Sowing Depth

Sow approximately:

10–15mm deep

Unlike very fine edible flower seeds, Nasturtium seed should be completely covered with soil or seed-raising mix.

Avoid planting unnecessarily deeply.

Best Sowing Season

Nasturtiums perform best during mild to warm conditions and are sensitive to significant frost.

As a practical Australian guide:

• Cool climates: spring to early summer after frost risk has passed
• Temperate climates: late winter to spring and again in autumn where frost is unlikely
• Subtropical climates: autumn through spring
• Tropical climates: cooler, drier months
• Hot or arid climates: autumn and spring, avoiding extreme summer heat

In mild frost-free areas, the sowing period can be considerably longer.

Germination

Expect germination in approximately:

7–14 days

Aim for a germination temperature of approximately:

15–21°C

During germination:

• Keep the soil evenly moist.
• Do not allow newly sown seed to dry completely.
• Avoid keeping the soil permanently waterlogged.
• Protect emerging seedlings from slugs and snails.
• Maintain reasonable airflow.

Plant Spacing

Space established plants approximately:

25–30cm apart

This gives compact plants enough room to branch while maintaining airflow around the foliage.

Position

Grow Nasturtiums in:

Full sun to partial shade

For the strongest flowering, provide plenty of direct sunlight.

Nasturtiums prefer:

• Full sun in mild conditions
• Light partial shade in very hot weather
• Well-drained soil
• Moderate moisture
• Good airflow
• Protection from significant frost

Soil & Drainage

Nasturtiums do not require highly fertile soil.

They generally perform well in:

• Average garden soil
• Moderately lean soil
• Raised beds
• Free-draining containers
• Well-drained garden borders

Excessively rich soil and heavy nitrogen feeding can encourage large amounts of foliage while reducing flowering.

Reliable drainage is more important than high fertility.

Watering

During germination and establishment, keep the soil:

Consistently moist but not waterlogged

Once established:

• Allow the upper soil to begin drying between waterings.
• Water deeply rather than applying frequent small amounts.
• Check pots regularly during warm weather.
• Increase watering during prolonged dry conditions.
• Avoid permanently saturated soil.

Established Nasturtiums tolerate some dryness, although severe water stress can reduce flowering.

Feeding

Nasturtiums generally require little fertiliser.

In average garden soil, additional feeding may not be necessary.

Container-grown plants in depleted potting mix may benefit from occasional light feeding.

Avoid heavy nitrogen fertiliser, which can encourage excessive foliage and fewer flowers.

Growing Nasturtiums in Pots

Compact Nasturtiums are particularly well suited to container growing.

Choose:

• A pot approximately 25–30cm wide or larger
• Effective drainage holes
• Quality free-draining potting mix
• Full sun to partial shade
• Regular access to water

For container growing:

1. Sow directly into the final pot where practical.
2. Position in good light.
3. Water regularly during establishment.
4. Allow excess water to drain freely.
5. Avoid excessive fertiliser.
6. Harvest flowers and leaves regularly.

Growing in Garden Beds

Nasturtiums work well in:

• Edible flower gardens
• Raised beds
• Vegetable garden borders
• Cottage gardens
• Rockeries
• Path edges
• Mixed ornamental and edible plantings

Compact plants can be positioned towards the front of beds without the long trailing growth of climbing types.

Encouraging More Flowers

For strong flowering:

• Provide plenty of sunlight.
• Avoid excessive nitrogen fertiliser.
• Maintain moderate moisture.
• Harvest flowers regularly.
• Remove fading blooms.
• Avoid severe overcrowding.

Regular deadheading can encourage continued flowering.

Harvesting Edible Nasturtium Flowers

Harvest flowers when they are:

• Freshly opened
• Clean
• Undamaged
• Dry rather than wet from rain or irrigation
• Grown specifically for culinary use

To harvest:

1. Pick flowers with clean hands or scissors.
2. Inspect carefully for insects.
3. Remove damaged material.
4. Rinse gently in clean water where required.
5. Allow excess moisture to drain.
6. Use whole or separate the petals according to the dish.

Nasturtium flowers have a:

Fresh, peppery and slightly spicy flavour with mild sweetness

They can be used with:

• Salads
• Sandwiches
• Savoury platters
• Canapés
• Cheese dishes
• Garnishes
• Stuffed-flower preparations

Harvesting Edible Nasturtium Leaves

Young, tender leaves are also edible.

Their flavour is:

Peppery and watercress-like

Young leaves can be used in:

• Salads
• Sandwiches
• Wraps
• Herb sauces
• Pesto-style preparations
• Savoury garnishes

Harvest healthy young leaves regularly rather than removing excessive foliage at one time.

Harvesting Buds & Immature Seed Pods

Unopened flower buds and young green seed pods are also edible.

Immature pods can be pickled and used as a tangy caper-style condiment.

Harvest pods while they are:

• Young
• Green
• Tender
• Free from deterioration

Do not confuse immature culinary pods with fully mature dry seed intended for planting.

Managing Hot Weather

Nasturtiums generally flower best during mild conditions.

During prolonged extreme heat:

• Provide afternoon shade where practical.
• Maintain reliable moisture.
• Check container plants frequently.
• Avoid severe wilting.
• Maintain airflow.

In very warm regions, the main crop may perform better during the cooler parts of the year.

Protecting Nasturtiums from Frost

Nasturtiums are frost tender.

In frost-prone climates:

• Wait until frost danger has passed before spring sowing.
• Start seeds under protection if an earlier crop is required.
• Protect young seedlings from unexpected cold snaps.
• Expect plants to decline after severe frost.

Food Safety for Edible Nasturtiums

Only consume Nasturtiums that have been correctly identified and intentionally grown for culinary use.

For edible flowers, leaves, buds and pods:

• Use clean gardening and harvesting equipment.
• Do not consume plants treated with chemicals that are not approved for edible crops.
• Avoid ornamental plants where treatment history is unknown.
• Do not harvest beside busy roads or from contaminated areas.
• Inspect flowers and leaves carefully for insects.
• Rinse gently with clean water where appropriate.
• Discard material showing mould, slime or significant deterioration.

Harvest & Storage

Nasturtium flowers and leaves are best harvested close to when they will be used.

For short-term storage:

1. Harvest clean, dry flowers or leaves.
2. Remove damaged material.
3. Place in a clean container or produce bag.
4. Refrigerate promptly.
5. Protect flowers from crushing.
6. Avoid excessive free moisture.
7. Use while fresh and crisp.

Young seed pods should also be refrigerated if they are not being prepared immediately.