Sowing & Planting Asparagus Seeds

Growing asparagus from seed takes patience, but it is one of the most rewarding ways to establish a long-lasting crop. Unlike crowns, which crop sooner, asparagus from seed gives you stronger, disease-resistant plants that adapt to your soil from the start. With the right timing and preparation, you can raise a healthy asparagus bed that will crop for 15 years or more.

When to Plant Asparagus Seeds

• In the UK, asparagus seeds are best sown indoors from February to April. This gives them a head start before they are planted outside once all risk of frost has passed.
• Outdoors, you can direct sow from late April to early May, but germination will be slower, and young seedlings are more vulnerable.
• The key is to avoid frost – asparagus seedlings are tender and need steady warmth to establish.

Quick tip: If you want to speed up germination, soak the seeds in warm water for 24 hours before sowing.

Starting Asparagus Seeds Indoors

Sowing indoors gives you more control over germination. Here’s how:

• Containers – Use deep pots, root trainers, or a cell tray with at least 5–7 cm depth. Asparagus forms long roots early, so depth is important.
• Soil/Compost – Choose a free-draining seed compost, enriched with a little sand or grit to avoid waterlogging.
• Seed Depth – Sow seeds 1–2 cm deep and cover lightly with compost.
• Spacing – Place 1 seed per cell/pot. This avoids tangled roots and makes transplanting easier.
• Temperature – Keep at around 18–21°C. Germination usually takes 2–3 weeks.
• Watering – Water gently but do not let the compost sit soggy.

Transplanting Seedlings Outdoors

Once seedlings are 8–10 weeks old and frosts are over (usually late May–early June in the UK), they can be hardened off and planted outside.

• Soil preparation – Asparagus needs a sunny, sheltered site with fertile, well-drained soil. Dig in well-rotted manure or compost beforehand.
• Row spacing – Space rows 30–45 cm apart.
• Plant spacing – Place seedlings 30 cm apart within the row.
• Planting depth – Dig a trench 15 cm deep, place seedlings in, and gently backfill. The crowns will naturally settle as the plants grow.
• Mulching – Apply an organic mulch to help retain moisture and suppress weeds.

How Many Seeds to Sow Per Hole

• Sow one seed per hole/cell.
• If direct sowing outdoors, you can drop 2–3 seeds in each station and thin to the strongest plant later.

This avoids wasted space and ensures strong individual plants.

Planting in Pots

If space is limited, asparagus can be started in pots or containers:

• Choose a container at least 30–40 cm deep.
• Use a loamy, free-draining compost mix.
• Sow one seed per pot, thin if necessary.
• Keep well-fed with a balanced liquid fertiliser through summer.

While asparagus can grow in pots, long-term cropping is best done in the ground for stronger crowns and higher yields.

Asparagus Fern Seeds

Some gardeners ask about “asparagus fern seeds.” This refers to the feathery foliage that grows after the edible shoots are cut. These ferns are part of the plant’s life cycle and are not a separate type of seed. By the end of the season, red berries will form, each containing small seeds – but these are not commonly used for propagation as they germinate less reliably than purchased seed.

When Can You Pick Asparagus?

Patience is key. Do not harvest spears in the first two years after sowing. Allow the plants to establish strong crowns and roots. From the third spring onwards, you can begin harvesting lightly, taking just a few spears per plant for 2–3 weeks. By year four, you can harvest fully for around 6–8 weeks.

Quick Reference Table – Sowing & Planting Asparagus Seeds

Recommended Asparagus Varieties

• Connover’s Colossal – a traditional variety with thick spears, very hardy and reliable.
• Asparagus Pea – not a true asparagus, but a delicious pea with a flavour reminiscent of asparagus.
• Explore our full asparagus seed range here.