Japanese Cherry Seeds (Sakura)

Japanese Cherry / Sakura — Prunus serrulata

With the Japanese Cherry (Prunus serrulata) you grow the symbol of Japanese spring yourself. In April clouds of pink-white blossom open before delicate foliage — Hanami (cherry-blossom festival) has been celebrated in Japan for over 1000 years. Spectacular red-orange autumn colour. Excellent as bonsai.

What's in the box

• 30 seeds Prunus serrulata — 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: 5 (Kaltkeimer) °C
• Germination: Stratifikation 8-12 Wochen kalt, dann 4-8 weeks

Position & care in detail

• Light: full sun
• Humidity: normal
• Substrate: well-draining, slightly acidic — houseplant compost + gravel
• Watering: regular, avoid waterlogging
• Feeding: in spring and early summer with complete fertiliser
• Wintering: Frost-hardy down to -25 °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
• Stratification: 8-12 weeks moist in fridge — no cold period = no germination
• Protect young plants from voles (they love the roots)
• First flowering from seed after 5-8 years — faster as bonsai

Good to know

• Native range: Japan, Korea, China — symbol of Japanese spring (Sakura)
• Height: 12 m, in a pot 2-4 (als Bonsai) m
• Iconic Japanese spring spectacle: pink-white blossom clouds
• Hanami festival celebrated for over 1000 years
• Spectacular red-orange autumn colour
• One of the most prestigious bonsai species

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 Stratifikation 8-12 Wochen kalt, dann 4-8 at 5 (Kaltkeimer) °C. Bottom heat (heat mat) shortens germination significantly, often by half.

Can it grow outdoors?
Yes, year-round — frost-hardy down to -25 °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.

Do seeds need a cold period?
Yes, mandatory. 8-12 weeks moist in fridge at 4-5 °C. Without stratification germination is often 0 %.

Does it bear edible cherries?
No — Prunus serrulata is purely ornamental. Fruits are small, dark and inedible.

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.