Spring Onion Ishikura Seeds

How to Grow Spring Onion Ishikura Seeds: Your Complete Guide

When and Where to Sow

Indoor Sowing

Start them off from February to March. Sow a pinch of 4-5 seeds per module, cover lightly with vermiculite or compost, and keep them somewhere around 10-15°C.

Outdoor Sowing

Sow outside any time from March to September, in shallow drills about 1-1.5cm deep with rows 15-20cm apart.

What to Do Next

Indoor-Sown Seeds

No thinning is needed. In April, move the modules to a cold frame to harden off, then plant each clump out around 7cm apart.

Outdoor-Sown Seeds

If you sow thinly there’s no need to thin them. Just pull them as you need them.

Maturity and Harvesting

Expect your first pulls around 10 weeks after sowing. Ishikura doesn’t form a bulb, so you can pull it at any size, from pencil-thin to as thick as a carrot, and one sowing will stand happily for months without bolting. It’s hardy, too, so a late summer sowing will see the winter through. The onions are versatile and perfect for salads and stir-fries.

Handy Tips

Successional Sowing

One sowing stands for so long that you don’t need to keep resowing, but if you like your spring onions young and slender, a short row every 2-3 weeks keeps them coming.