With lots of harvesting and clearing of annual vegetable beds going on I've started to think about next year's growing.
In the world of perennial vegetables we've continued to enjoy perennial kale, sea beet and sorrel over the summer and daylilies are beginning to become normal fare. There should be scorzonera and skirret roots to eat soon and fresh Babington leek shoots later in the year. The asparagus that I despaired over earlier in the year eventually threw out one frond per plant so perhaps we shall have a harvest in 2014. So I feel the perennial vegetable adventure is going quite well and after mulling it over for a while I've decided to plant all but one of my twelve vegetable beds with perennials. I have a half-plot on another allotment site where I can carry on growing annual vegetables. The remaining bed on the perennial site I plan to keep for self-seeding opium poppies (because we like collecting the seed for bread and cakes) and perhaps a few other self-seeders.
So what to put in the new beds? So far I've got half-beds (about 2 square metres) of tree onions, potato onions, sea kale, sea beet, Good King Henry, scorzonera, common mallow, Daubenton kale, skirret, Babington leeks, a whole bed of asparagus and another of assorted heritage kales and sea cabbage. Well, to start with, the common mallow is coming out. The young leaves are great added to a salad but are too coarse and lacking in flavour for me to enjoy as a cooked vegetable.
Common mallow Malva sylvestris
Mallow leaves collected for cooking
Also the plant succumbs to rust very readily. So I think I'll just keep one plant and relegate it to a spot in the herb garden.
Rust on mallow leaves
That leaves me with space for nine more perennial vegetable crops if I give each one a half bed.
Jerusalem artichokes, Chinese artichokes and daylilies are at my other plot at present so I'll bring those over. I have a couple of globe artichokes plants that would love a bed of their own; they will get one except that they will have to share with another variety or two and a cardoon when I get them!
Up until now I've tended not to consider the various South American tubers like oca, mashua, ulluco and yacon as perennial vegetables on the grounds that they aren't very hardy and their tubers are usually taken up in autumn and replanted in the spring. To my mind that makes them as much work as an annual vegetable. But Rhizowen from Radix (Root Crop Research and Ruminations) has given me hope that I might be able to overwinter tubers by burying them extra deep. Frost doesn't get very deep into the ground in this country - although it depends how severe and extended a cold period we have. Building foundations are usually put in to a depth of 70cm to be below the level of any possible frost action but I get the impression that pushing a tuber 30cm down would render it safe in all but the very harshest winters. I'd be quite happy to replant a set of tubers at the same time as harvesting. I already do that with some other crops like the potato onions and Jerusalem artichokes and it's quick and easy to do when the ground has just been dug for harvesting. So I think I'll be experimenting with some of these interesting vegetables.
Oca, mashua, ulluco and yacon tubers Courtesy of Jonathaneo, Nzfauna, Farmcore
There's lots more possibilities for perennial vegetables that might be worth growing in quantity - many plants that I've heard about but not had the chance to grow yet and others that I've planted but not yet eaten, like Camassia and Tigridia bulbs for example. And then there's all those I don't know about yet. The adventure continues........
N.B. I sell a range of perennial vegetable plants on my website.