Blue Gum Eucalyptus Seeds

Blue Gum Eucalyptus — Eucalyptus globulus bicostata

With Eucalyptus (Eucalyptus globulus bicostata) you grow the iconic Blue Gum yourself. Silver-grey, heart-shaped juvenile leaves are popular for floristry and wreaths. Distinctive eucalyptus scent (cineole) acts as expectorant and insect repellent. Fast-growing (1-2 m per year early on), hardy to -8 °C.

What's in the box

• 100 seeds Eucalyptus globulus bicostata — tested for germination
• Illustrated growing guide in 8 languages (on the seed card)
• Minimum shelf life: 2 years from packaging date

Growing in brief

• Prep: soak seeds 24 h in lukewarm water
• Sowing: in loose, moist seed compost
• Temperature: 20-25 °C
• Germination: 2-4 weeks

Position & care in detail

• Light: full sun
• Humidity: moderate
• Substrate: well-draining — houseplant compost + sand
• Watering: moderate, established trees very drought-tolerant
• Feeding: 1-2× per season
• Wintering: Frost-hardy down to -8 °C

Sowing date & timeline

The ideal sowing date depends on the plant type.

Indoors sowing is possible year-round if heat mat and grow light are available. January to April is optimal: after germination the seedling can grow vigorously through spring/summer before light declines in autumn.

Directly outdoors only for frost-hardy species and after mid-May. Frost-tender species should first be raised in pots indoors, then hardened off after mid-May before being placed outdoors.

Pot choice & transplanting

Pot size and transplanting evolve with the plant:

• Sowing: 6×6 cm seed tray per seed or tray pots. Use low-nutrient seed compost.
• Seedling: prick out at 2-3 true leaves into a 9 cm pot with nutrient-rich compost.
• Established: repot every 1-2 years into a pot 2-3 cm larger. Mature plants need 5-30 L pot volume depending on the species.

Tips & tricks

• Use a heat mat: bottom heat at 25 °C speeds germination by weeks
• Mini greenhouse: cover seed tray with a transparent lid or cling film — keeps humidity high
• Prefer fresh seed: the fresher the seed, the higher the germination rate — sow soon after delivery
• Cut fresh branches for bouquets and wreaths — silver-grey juvenile leaves are decorative
• Winter the pot bright and cool (5-12 °C)
• Crushing leaves releases fresh eucalyptus scent — natural moth repellent

Good to know

• Native range: Tasmania and southeast Australia
• Height: 60 m, in a pot 1-3 m
• Iconic silver-grey, heart-shaped juvenile leaves — popular for floristry
• Distinctive eucalyptus scent (cineole) — expectorant and insect-repellent
• Hardy to -8 °C — can survive mild winters in Ticino
• Fast-growing: 1-2 m per year in early years

Seed storage

Unopened or leftover Saflax seeds keep for 2 years if stored correctly. Keep dry, cool (vegetable drawer in fridge) and in the original packaging — moisture drastically reduces germination. Test germinability before each sowing: 5 seeds on moist kitchen paper in a covered plastic dish at 22-25 °C — if 4-5 germinate, the rest are reliable.

FAQs

How long does germination take?
Typically 2-4 at 20-25 °C. Bottom heat (heat mat) shortens germination significantly, often by half.

Can it grow outdoors?
Yes, year-round — frost-hardy down to -8 °C. In a sheltered position it thrives without issue.

How fast does it grow?
Slow in the first year (establishment phase), then notably faster from year two with optimal care and the right position.

Do I need special tools?
A simple seed tray, compost and a bright position are enough. A heat mat (~CHF 30) and a mini greenhouse noticeably improve germination but are not mandatory.

What if seeds don't germinate?
Patience — many exotic species take 4-12 weeks. Check temperature (heat mat!), substrate moisture (evenly moist, never wet) and whether the seeds require stratification or scarification. Saflax seeds are tested for germination before dispatch.

Can I use leaves for essential oils?
Yes — dried leaves give the classic eucalyptus scent. For aroma baths, inhalation, or as moth protection in wardrobes.

Will it survive Swiss winters?
In Ticino and very mild locations yes (down to -8 °C). Otherwise grow in pots and shelter in winter.

How best to store leftover seeds?
In the sealed original packet, dry and cool (vegetable drawer of fridge at 4-8 °C). Germinability is preserved through the full 2-year shelf life. Reseal immediately after opening and acclimatise to room temperature before sowing.