Allium cepa
Origin: Great Britain
Improvement status: Cultivar
Seeds per packet: ~150
Germination tested 01/2026: 92%
Life cycle: Biennial
Ailsa Craig' was introduced in 1887 by David Murray, the gardener of a British nobleman, the Marquis of Ailsa, at Culzean Castle in the Scottish town of Maybole, South Ayrshire. It's named for the island of Ailsa Craig — famously the location of the only quarry for the unique microgranite utilized for curling stones — which can be seen from Culzean Castle. Under ideal conditions, a single onion of this old heirloom can reach sizes upward of 5 pounds! It has pale yellow skin and whitish flesh that has a sweeter flavor than most onions, making it ideal for fresh use. This variety has a reputation for not storing very well, so it's typically recommended for fresh use or processing for long-term pantry uses (dried, powdered, pickled, etc), but this special strain has been selected for much improved storage ability.
Our growers, Kelly Gelino and Sebastian Aguilar of Summertime Seeds in Oregon's Willamette Valley, have been growing 'Ailsa Craig' for over two decades. They worked for several years with the late great plant breeding legend John Navazio, particularly trying to improve this variety's uniformity and original shape, in addition to its storage quality. They've also selected it for strong production under strictly organic conditions. We're grateful to be offering these special seeds.
GROWING TIPS: Start onion seeds indoors in flats a couple months before last frost. Plant out in rows once all danger of frost has passed. Plants spaced closer together will yield smaller bulbs, but again this variety can grow very large.
Photo with hand:
[Photo by Wikimedia Commons user MOs810, available under a Creative Commons Attribution-Share Alike 4.0 International license.]