How to Grow Coast Redwood from Seed
Sequoia sempervirens

The plant

What is Coast Redwood — the Tallest Living Tree on Earth?

Sequoia sempervirens is not just a large tree — it is the largest living thing by height that has ever existed on this planet. The tallest measured individual, named Hyperion and discovered in 2006 in Redwood National Park, California, stands at 115.92 metres. Its exact location is kept secret to protect it from tourism damage.

Coast Redwood is native to an extraordinarily narrow strip of land: a 750-kilometre coastal band running through northern California and a small part of southern Oregon, rarely extending more than 50 kilometres inland. This range is defined by a specific microclimate — the coastal fog belt, where summer fog rolls in from the Pacific and provides moisture during California's dry summers.

The tree is an evergreen conifer — unlike its close relative Metasequoia (Dawn Redwood), it keeps its dark-green, flat needles year-round. It grows rapidly in the right conditions: 0.6–1 m per year once established, reaching 20–30 m in a garden over several decades. In cultivation outside California, trees of 40–50 m have been recorded in the British Isles and parts of western Europe.

Quick facts

Sequoia sempervirens at a Glance

Growing guide

How to Grow Coast Redwood from Seed — Step by Step

Seeds are tiny — about 3–4 mm. Handle carefully. Fresh seeds germinate at 40–60%; older seeds drop below 20%.

1. 01
   Cold Stratification — 4 to 6 Weeks

   Mix seeds with lightly moist peat or vermiculite in a sealed zip bag. Refrigerate at 2–4°C for 4–6 weeks. Sequoia seeds are naturally shed in autumn and require cold to break dormancy. Check every 10 days — medium should be barely moist, never wet. Seeds that begin to sprout in the bag are ready to sow immediately.
2. 02
   Surface Sowing — Never Cover

   Fill shallow trays with fine seed compost mixed with perlite (2:1). Moisten thoroughly. Press stratified seeds onto the surface with a finger — do not cover with compost. Coast Redwood seeds require light for germination. Cover tray with clear plastic lid to maintain humidity. Keep at 18–22°C in a bright position.
3. 03
   Germination — 14 to 35 Days

   Seeds typically emerge in 14–35 days at 18–22°C. The seedlings are tiny at first — be patient. Maintain consistent moisture and 14–16 hours of light. Remove the plastic cover gradually over 3–5 days once seedlings reach 2–3 cm. Damping off (fungal collapse at stem base) is the primary risk — ensure good air circulation and avoid overwatering.
4. 04
   First Year — Humidity Above All

   Transplant to individual 9 cm pots when seedlings reach 5–8 cm. Sequoia sempervirens evolved in coastal fog — it needs high atmospheric humidity, not just wet soil. Mist foliage daily in dry indoor conditions, or group pots together to create a humid microclimate. Use slightly acidic, well-drained soil (pH 5.5–6.5). Expect 15–30 cm by end of first season in good conditions.
5. 05
   Outdoor Planting — Zone 7+ and Oceanic Climate Only

   Plant out in second or third year, after last frost. Sequoia sempervirens tolerates short frosts to −15°C but is not suitable for continental winters (Germany, Poland, inland France). It thrives in oceanic climates: southern England, coastal France, Ireland, Pacific Northwest USA. Choose a sheltered, humid position away from drying winds. Water regularly through the first two summers.
6. 06
   Long-Term Growth — 0.6 to 1 m Per Year

   Once established in open ground, Coast Redwood grows 0.6–1 m per year, reaching 15–25 m in a garden over 20–30 years. In favourable European locations (southwest England, Brittany, Basque Country) trees of 40–50 m have been recorded. The tree is evergreen — dark-green needles year-round — with distinctive reddish-brown bark developing with age. Trunk diameter can reach 6–9 m at full maturity over centuries.

Compare

Coast Redwood vs. Dawn Redwood vs. Giant Sequoia

Avoid these

Common Mistakes When Growing Coast Redwood from Seed

FAQ

Frequently Asked Questions