Perennial vegetables

Although any favourite crop is worth whatever efforts it takes, on the whole it's better to grow as much as possible with the least work possible. (Unless you use your garden as a gym that is.) Fruit trees are least work each year and soft fruits nearly as good, culinary herbs take little effort but only a little of each is required. Unfortunately our common vegetables are a lot of work with all their annual sowing, thinning or transplanting and care. To say nothing of the autumn dig! Perennial vegetables just have to be a good idea.

As with the other more permanent crops there is this tremendous saving in work each year just because of their permanence. Once established they only need the odd bit of attention and a good mulch and most of them then crop for many years. But only if they were well chosen and well planted in the first place of course!

Their relative permanence encourages the build up of a healthier ecosystem around them than amongst annual vegetables. Especially if they are mulched with a coarse material such as straw or rough bark; I find both increase the number and variety of spiders and beetles, particularly the former.

Because of their reserves built up over the years perennial crops are more regular and reliable than annual. And, their biggest advantage is that most of them crop early in the year well before most annual crops are even part grown. Indeed this is when they are most needed as the stored crops will also be running out and deteriorating about this same time.

Unfortunately there are not that many true perennial vegetables compared to the far more numerous perennial culinary herbs which are used for their flavour rather than for bulk. And of course there are those that have the potential to be developed further but which currently are more of a standby in case of famine. The majority of perennial croppers produce foliage which can be turned into rather nondescript spinach. Only a few have been bred to give the qualities we demand for our table.

Asparagus is probably the first perennial vegetable most of us will think of, and well deservedly. Esteemed since Roman times this crop is a delight but not quite as low labour as some of the others. Asparagus takes a couple of years to establish and build up enough energy to crop well and then can last a couple of decades. It's without doubt best sown in situ but this can be inconvenient. Planting young crowns is better than older and they need handling with care, and urgency. Asparagus grows well under a mulch but crops earlier if this is raked aside to let the sun warm the soil and roots. The newer cultivars are all worth trying, many are 'all male' but do not spurn those that also give female plants as these usually produce the fattest shoots. More space per plant gives bigger shoots and more of them, as does irrigation, seaweed sprays and enriching the soil. I have found that the best shoots I get are the ones that come for free on my vegetable beds. Sure the plants compete with whatever goes near them but I can't think of any crop that I wouldn't rather have more asparagus instead of...

Good King Henry is another excellent shoot, very much unknown and under-rated, remarkably quick and easy to grow in quantity from seed. In fact this is a weed but as it is very edible then it can be allowed to self seed and colonise any damp area. If you want good shoots though give each plant space and deflower them to build up their strength. The young leaves also make a good spinach and hens appreciate the leaves. (Turkish rocket, Bunias orientalis, is similar in many ways and used likewise but is mustardy and hot.)

Hops also make edible spring shoots but are rather bitter so the water needs salting and changing during cooking. Obviously they need tall supports and can be left to go on to give a crop of flowers for brewing as well. Interestingly enough, as with asparagus, these are dioecious plants with male flowers on one plant and female on another. Thus it ought to be fairly easy to breed a bigger fatter shooted variety because the current sorts are rather poor fare. Likewise around the world many other perennials have been grown and their shoots eaten but we would probably find many hardy ones too tough or such as Solomon's seal too poisonous for modern stomachs, but they could be improved.

Bamboo as a food from our gardens is almost completely overlooked yet many species have edible young shoots, mine proved too tough and bitter for my palate yet obviously there is potential here. Many sorts are eaten in China and the East but few references suggest sorts for here. Does anyone grow a hardy variety here in the UK they eat and can personally vouch for and recommend?

Seakale is too much like cabbage for my liking yet makes an excellent alternative. The mature leaves are attractive enough for use as a foliage plant. I found the seeds produced variable, often more bitter, plants and recommend slips of Lily White are grown. Like asparagus this is a seaside plant so responds well to seaweed sprays. Of course this needs blanching to be edible but if done in situ this is not much effort.

Rhubarb is much neglected yet a very reliable early source of fresh food each year. The varieties we eat are all fairly recent as they were bred by the Victorians from earlier medicinal species. It's odd we have never widely used rhubarb as a savoury vegetable but always as a fruit; may I suggest rhubarb and cheese pie??? I find a bottomless oil drum or dustbin full of loose straw a far better blancher than the traditional bottomless bucket.

Stinging Nettles verge on being nothing but a weed but I must admit I can't be content in early spring without the odd meal of nettle top soup. This is so good I feel obliged to include them as a vegetable -and they have never been selected for plump succulence; now there's a possibility.

Globe Artichokes are so decorative they could go to the flower garden. I find them variable from seed and it's best to choose improved sorts. The crowns can be as long lived as asparagus in the right site but are soon destroyed by really hard winters or slugs. (Geese also kill the over-wintering crowns off very effectively as I accidentally found out.) Admittedly you can only eat so many of the flower buds as such but they can be processed to make a superbly tasty paté. I've grown these intermixed with raspberries. If like me you foolishly let the buds flower that are intensely beautiful and always full of humble bees who seem intoxicated by their perfume. The cardoon is almost identical in everything except flower size but can not be cropped as a perennial and only successfully made edible when grown as an annual. It's said the heads of the short lived, usually biennial, Milk thistle, Silybum marianum, are edible after the manner of globe artichokes but they are very small and even more spiny so need much improving. I've tried most things but these defeated me!

Perpetual Broccoli is sadly only a tri-ennial at best, producing small mini-cauliflower heads each spring as it becomes ungainly. This has possibilities and it is only as I write this that I wonder whether it ought not be cut back hard after cropping to stop it becoming so ungainly? Certainly cabbages and some other brassicas will come again if the stalks and roots are left in the ground, for up to three years or so, but only if prevented from wasting their energies by flowering. I also often propagate cabbages by detaching some of the small shoots that spring from ground level.

Jerusalem Artichokes are not really a perennial, but as you can never extricate all the nodules then they become effectively perennial. (Chinese artichokes, are similar on a dwarf scale but cannot be left to fend for themselves.) These are almost perfect; productive, reliable, pest and disease free, fairly unrelated to other crops, trouble free. It's just you can only use so many of the tubers; they're just not as usable everyday as are potatoes. The flowers are sweet and loved by bees and the stems make good wildlife shelters, and they will grow almost anywhere on almost completely impoverished soil!

There are several perennials such as chives and bunching onions that can produce significant quantities when grown as semi-permanent edgings and likewise for the many culinary herbs. Horseradish is almost immortal but again you can only use so much of it -pity no-one has bred a less pungent more succulent root yet.

Dandelions are almost perennial and I cut them back and put a pot over them to get their blanched leaves of each one in turn letting them recover after. These really are excellent fare especially fried with shallots, bacon and eggs. Sow more dandelions as these can be grown almost anywhere and are a rich source of minerals. They can be given a bed of their own -or you could use them as a way of cropping the lawn!