This might sound like a rather abrupt change of subject for this blog, but no no, I’m still talking about vegetables, and any high jinks herein are purely plant-based. It does, however, begin with a seedy tale of contacts made on the internet…

A bit over a year ago, I offered some turnip-rooted chervil seed to members of a Facebook group I’m on. A few people replied and little packets duly went out. One recipient kindly sent me some kale seeds in exchange, along with a note explaining that they were from an OP grex. A quick Google later, I knew what an OP grex was. Essentially, a grex is a particular cross between two previously-named gene pools (which may be species or may be crosses themselves), plus any further offspring that arise from members of the grex crossing with each other or with the original parent populations. OP simply stands for open-pollinated.

Usually, seed-saving is quite a conservative affair. The aim is to propagate a named variety, keeping it as ‘clean’ as possible by avoiding pollination by any other variety. Seed-saving manuals give the isolation distance required for each species: up to a mile in the case of the brassicas. This keeps the variety stable, of uniform and predictable qualities. This is particularly important when one ancestral species has differentiated into a number of quite different forms: cauliflower and Brussels sprout will cross quite happily, but their offspring is unlikely to be very useful. The kale seeds I received represent a different philosophy.

The grex originated in a rare flowering of Daubenton’s perennial kale, pollinated by a number of adjacent brassicas. Since then enthusiasts have been breeding in as much diversity as they can. The idea is that individual growers can then select for whatever characteristics they like, according to local conditions and personal preference. If the long-lived characteristics of Daubenton’s are also selected for, this could eventually yield a galaxy of perennial kales, from super-cool Tuscan types to my personal hope, a perennial Pentland Brig.

Here you can see the diversity in a single row of OP kale, showing variation in leaf size, form, texture, coloration and yield. In the next generation, I’ll be selecting from this variety on five criteria: leaf size, yield, tenderness, funkiness and lifespan. Perennial kale is a great candidate for this approach. Uniformity isn’t particularly critical in kales: there are some of these plants that I won’t be breeding from, but none that are a waste of space.

Furthermore, a plant with a particularly good combination of qualities can then be propagated vegetatively by cuttings so that it is preserved. A number of other crops also have these characteristics: mostly ones which propagate by seed but also by bulbs or tubers. Most importantly, there is the potato. We usually buy ‘seed’ potatoes in bags of tubers from a single clone, but they also grow perfectly well from the seeds contained in the little tomato-like fruits that you may see on the vines. If you get a good one, it can then be propagated indefinitely from the tubers in the normal way. One variety I’m growing from is Magic Dragons, a very blight-resistant line that I was sent by Tom Wagner. The Kenosha Potato Project is an amazing network of true potato seed enthusiasts.

The alliums are another group with lots of potential. The problem with many asexually-propagated vegetables is that they slowly lose the capacity to produce seed at all, meaning that opportunities for future breeding are lost. Sometimes they can be coaxed back into seeding, as in the work that Kelly Winterton has done on potato onions (which are probably the same thing as shallots).

But why would you want to do this? Aren’t there proper plant breeders out there, honing the perfect varieties for us? Well yes, there are, but they can never hope to produce the range of locally-adapted varieties that an army of amateur enthusiasts can. Also, the nature of their trade means that they have to actively breed diversity out of their seed lines so that they are uniform and stable. Where this is a virtue, I’m quite happy to rely on the big guns to do the work, but where it isn’t, I’d rather have a joyous riot of diversity in my garden.

Big plant breeders are currently trying to claim rights far beyond a just reward for the work that they actually do, patenting not just individual mutations but whole broad characteristics of crop plants. This stifles seed sharing and the genetic heterogeneity that is essential for future resilience. The Open Source Seed Initiative is one response to this. Getting maximum diversity into seed lines is another, as explained in the excellent article Linux for Lettuce. Above all, it is simply so much more fun. The anticipation, interest and potential in my OP kale are simply so much higher than in any ‘clean’ variety I have ever grown. I’m now taking this approach to all the legumes and leaf crops that I grow too. I’ll leave you with a few more of those kales…