Asparagus Seed Germination

Starting asparagus from seed can feel slow compared to other vegetables, but with the right preparation you’ll achieve strong, healthy seedlings. Many UK gardeners ask the same questions about soaking, germination time, and seed viability. Below we’ll cover them all in detail.

How Long Do Asparagus Seeds Take to Germinate?

• On average, asparagus seeds take 14–21 days to germinate at a steady temperature of 18–21°C.
• If temperatures drop below 15°C, germination may take up to 30 days or more.
• Using a heated propagator or warm windowsill speeds things up and ensures more even sprouting.

Should You Soak Asparagus Seeds Before Planting?

Yes — soaking asparagus seeds is highly recommended.

• How long to soak asparagus seeds before planting: Place them in warm water for 12–24 hours before sowing.
• Soaking softens the hard seed coat and reduces germination time by several days.
• Some gardeners even pre-sprout seeds on damp kitchen paper before potting them up.

How Many Days Until Asparagus Seeds Sprout?

• Expect the first sprouts in 2–3 weeks, but don’t be surprised if some take up to 4 weeks.
• Seeds rarely all sprout at the same time — patience is needed.
• Once sprouted, seedlings will quickly send down long roots, so deep pots or root trainers are essential.

How Long Do Asparagus Seeds Last?

• When stored in a cool, dry, airtight container, asparagus seeds will remain viable for around 3 years.
• Germination rates are highest in the first 1–2 years, dropping as seeds age.
• Avoid keeping seed packets in damp sheds or greenhouses, as moisture shortens lifespan.

How to Germinate Asparagus Seeds – Step by Step

1. Soak seeds in warm water for 12–24 hours.
2. Fill pots or trays with free-draining seed compost, ideally mixed with sand or perlite.
3. Sow 1–2 cm deep and cover lightly with compost.
4. Keep warm — aim for 18–21°C. A propagator, heat mat, or warm airing cupboard works well.
5. Water gently, keeping the compost moist but not waterlogged.
6. Wait 2–3 weeks for seedlings to emerge.
7. Once seedlings appear, move to bright light to prevent leggy growth.

How Long Do Asparagus Seeds Take to Grow?

• From sowing to a young transplantable seedling takes about 8–10 weeks.
• After that, seedlings are moved outside, but full cropping takes patience:
• Year 1 – Germination, seedling growth, fern development.
• Year 2 – Strong root and crown establishment, no harvest.
• Year 3 – Light picking of a few spears.
• Year 4 onwards – Full harvest season (6–8 weeks each spring).

When Are Asparagus Seeds Ready?

• Seeds are ready to sow from the packet at any time within their 3-year viability window.
• In the UK, the best sowing season is February–April indoors.
• You’ll know they’re “ready” in the garden sense once they germinate into strong seedlings with 2–3 sets of true leaves — at that stage, they can be potted on or prepared for hardening off.

Quick Reference: Asparagus Germination Facts

Recommended Seeds

• Connover’s Colossal – vigorous, traditional variety.
• Asparagus Pea – a different crop, but a delicious option with asparagus-like flavour.
• Browse the full asparagus seed range here.