What if you could plant just once, and then enjoy harvests for many years to come with minimal effort? Amazingly, you can – if you grow perennial vegetables!
Perennial vegetables have superb culinary qualities, and often good looks too. But what I especially love about perennial vegetables is that many fill the ‘hungry gap’ – that time of year in spring when winter’s vegetables are over but the newly sown crops of the season aren’t quite there yet.
But – confession time – since I moved to my current home, I haven’t grown nearly enough of them in my garden, so it’s time to put that right. Read on or watch our video to discover five of the best perennial vegetables...
Grow Gargantuan Globe Artichokes
First up is the globe artichoke – a big, bold plant that makes an incredibly architectural statement. I love it because it looks so darn good – it’s just such a striking plant in its own right!
They can be grown from seed but you can get a head start by planting young plants. I’m planting mine into an area of ground that gets plenty of sunshine and is well drained. If you’re planting more than one, leave at least 3ft (90cm) between plants. I’ll need to keep the area free of weeds during the growing season, water well in dry weather, and mulch the soil around plants with organic matter each spring to feed all that eager growth. If winters are very cold where you are, consider adding a mulch of straw or compost over the plants in winter to protect them from the worst of the freezing weather.
The globe’s artichoke’s tight flower buds are harvested once they reach about golf ball size, and before they open. The buds can be steamed or boiled until tender then, to eat, the individual scales are picked off and dipped into a butter sauce, hollandaise sauce or some other dipping sauce before sucking the delicious flesh from each scale. You’re then left with the tender heart – the real centrepiece to the whole affair!
You’ll often get a second cut of buds a few weeks after harvesting the first, but do allow some of these to open out and flower, because they are one of the most effective bee-attracting flowers I’ve ever seen.
Another perennial vegetable similar to the globe artichoke is cardoon. It’s just as dramatic and eye-catching and grown in much the same way – plenty of warm sunshine and a well-drained soil – but in this case it’s not the flower buds you harvest, but the stems. Harvested cardoon looks a lot like a bunch of celery and can be used in similar ways: baked, gratinated or turned into soups, for example.
If you’re looking for another bold statement-of-a-vegetable for cooler, damper parts of the garden, you can’t beat rhubarb.
Save Effort By Planting Babington’s Leek
Babington’s leek is a type of perennial leek which I’m told has a mild, garlicky leek flavour. I’m planting the tiny bulblets into pots of all-purpose potting mix to grow on under cover before planting out in spring. The bulblets are going in about an inch (3cm) deep. You could plant them directly outside into well-prepared soil, but I’m keen to get them started where I can keep a watchful eye over them, avoid any risk of them rotting away, and to keep them clear of my dog who seems to love eating leeks! Once they’re up and underway, they’ll go outside, spaced about 6in (15cm) apart to establish a decent-sized clump.
Plants need to be left alone in the first year after planting to bulk out and establish. Then from the second spring you can begin harvesting the stems, cutting them off at ground level but leaving the bulbs below ground intact to continue growing.
Plants send out a flower stalk in early summer. The flower stalks produce lots of tiny bulbils, which will either fall to the ground or weigh the whole stalk down onto the ground so that the bulbils make contact with the soil that way. Once in the ground, these bulbils will also root and eventually form new plants, spreading the clump still further.
Other perennial alliums to try include the Welsh onion, a type of perennial bunching onion, and the tree onion (also known as the Egyptian walking onion), which gradually ‘walk’ their way across your garden using their top-setting bulbils that flop down onto the ground, root, and grow.
Pick Perennial Kale All Year Round
Another perennial vegetable I’m making room is perennial kale, and here’s why. Perennial kales can reach pretty epic proportions – up to person height – but are easily kept in check through regular harvesting. They’re very hardy and very resilient, easily shaking off any caterpillar damage. And the best bit: they can be harvested almost year-round, anytime you need fresh, tasty greens, straight from the garden.
The best way to introduce perennial kale is with cuttings taken from side shoots. Big chunky cuttings, which are about 6in (15cm) long. Mine came in the mail, trimmed and ready to plant straight away. The cut has been made just below a bud and the lowest leaves stripped off to reduce the stress on the cutting. I’m planting them into pots of potting mix. I’ll keep the potting mix moist to encourage root growth, while keeping them in a bright, sheltered position. They’ll then go outside in spring to their final home in the garden.
There are several varieties of perennial kale available including Taunton Deane, Daubenton’s kale, Ethiopian kale (a great choice for warmer climates), and the very hardy Sutherland kale, with its origins in the crofting communities of the North of Scotland.
What if I told you there was a root crop that’s as easy to grow as potatoes but that suffers few of the pests and diseases associated with the common spud? Well, that’s oca, also known as the New Zealand yam.
Oca can be cooked just like potatoes – boiled, fried or baked – but also eaten raw – sliced into salads for a lovely lemony tang. And that lemon zing is also found in the leaves, which may be harvested fresh as a welcome extra salad staple.
Oca isn’t frost-hardy, so to get it off to a strong start you’ll need to plant the tubers into pots of potting mix then grow them on under cover until you can safely plant them out after your last frost, setting plants about 3ft (90cm) apart.
The tubers form very late in the season, in autumn, and are harvested only after all the foliage has died off, usually with the first hard frost. Tubers can then be lifted, brought inside to dry off and stored, like potatoes, in a cool, frost-free place. Some of these tubers can then be planted the following spring to keep the harvests coming.
Fresh Asparagus For Years To Come
Have I saved the best till last? I reckon so! My final must-grow perennial vegetable is the royalty of veggies: asparagus. Asparagus loves a very free-draining soil and does best basking in full sun. You’ll need a little patience, but boy is it worth it.
The easiest way to begin an asparagus bed is using dormant roots, or crowns, which are available from early spring. Plant them as soon as they become available into a patch of ground you can dedicate solely to this hard-working perennial. Prepare the ground by removing any weeds, work in some garden compost, then dig a trench for your asparagus crowns about a foot (30cm) wide and 8in (20cm) deep. Make a ridge along the bottom of the trench then splay your crowns out along the top. Set them about 18in (45cm) apart along the trench, leaving the same distance between further trenches. Backfill with soil then water to settle.
At this stage you can add a mulch of compost or well-rotted manure to help keep weeds in check, and to help slowly feed the roots below. You’ll then need to resist the temptation to cut spears for at least two years, to give plants time to establish. Then from the third spring onwards, harvest as they appear for up to six to eight weeks until about midsummer, when the stems should be left to develop their ferny foliage, which will recharge the crown’s resources for next year.
You’ll need to watch out for asparagus beetle, which can chew notches in the spears, making them crooked, and munch on the foliage. Control them by picking or knocking them off into soapy water, and be sure to tidy away old, dead foliage at the end of the season. Other than that, they’re largely pest free.
There are lots of other perennial vegetables worth seeking out, many of which are flower border favourites: for example, the tender young leaves of hostas can be eaten, or how about daylily flower buds – all delicious for sure! Don’t be afraid to explore but do your research so you know what’s safe to eat.