Bupleurum rotundifolium Green Gold | Thorough Wax | Seeds

Bupleurum Green Gold is a versatile annual grown for its airy sprays of yellow-green flowers, decorative foliage and long, branching stems. Its fresh lime-green tones bring lightness and texture to bouquets, making it a useful filler for both home gardeners and cut flower growers.

Also known as thoroughwax or hare’s ear, this variety combines beautifully with roses, sweet peas, snapdragons and other seasonal flowers. In the garden, its upright growth adds a soft, natural look to mixed borders.

Plant Information

Botanical name: Bupleurum rotundifolium
Common names: Thoroughwax, hare’s ear
Variety: Green Gold
Family: Apiaceae
Plant type: Annual
Seed type: Open-pollinated
Plant habit: Upright and branching
Flower colour: Yellow-green to lime green
Height: Approximately 60–100 cm, depending on growing conditions
Plant spacing: Approximately 15–25 cm
Days to Maturity: Approximately 80–90 days from sowing to the first harvest under favourable growing conditions.
Position: Full sun or partial shade
Soil: Average, well-drained soil
Flowering: Summer into autumn, depending on sowing time and climate
Uses: Bouquet filler, fresh and dried flowers, decorative foliage and mixed borders

Fresh Lime-Green Colour for Bouquets

Green Gold produces small flowers surrounded by decorative yellow-green bracts. These create an airy, branching framework that supports other flowers in an arrangement without overwhelming them.

Its colour works equally well with soft pastels, white flowers and richer summer shades. Grow a patch alongside your favourite cutting flowers for a ready supply of fresh bouquet filler.

Sowing & Germination

Sowing method: Direct sow or start in plug trays
Sowing indoors: Approximately 5–8 weeks before planting out
Sowing depth: Approximately 0.5–0.6 cm
Cover seed: Yes; darkness supports germination
Germination temperature: Approximately 13–16°C
Germination time: Usually 14–21 days; some seed lots may germinate sooner

Bupleurum germinates best in cool conditions. Sow into a fine, moist seedbed or seed-starting substrate, cover the seeds and maintain even moisture without waterlogging.

Avoid placing seed trays on a hot windowsill or using excessive bottom heat. Allow enough time for germination before discarding trays.

For direct sowing, choose a period when the soil is cool and workable. Thin seedlings once their true leaves appear.

If starting indoors, use individual cells and transplant carefully before the roots become crowded. Harden off seedlings gradually before planting out.

Growing Conditions & Care

Choose a sunny position with well-drained soil. Partial shade is also suitable, particularly where summers are hot.

Water regularly while plants establish, then as needed to prevent prolonged drought stress. Avoid constantly wet soil and excessive feeding.

Space plants approximately 15–25 cm apart. In exposed locations, support netting can help keep the tall, branching stems upright and easier to harvest.

For a longer cutting season, make successive sowings where local conditions allow. Cooler sowing periods generally give the best start.

Harvesting for Fresh Bouquets

Cut when the flower heads begin to develop their characteristic yellow-green colour and the stems are firm.

Harvest during the cooler part of the day, remove foliage that would sit below the waterline and place stems promptly into clean water. The branching sprays are useful for adding volume, movement and a natural finish to mixed bouquets.

Drying Bupleurum

For dried arrangements, harvest when the flowers are fully open. Remove excess foliage and hang small bunches upside down in a dry, shaded, well-ventilated place.

Green Gold adds delicate structure to dried bouquets and seasonal floral decorations.