Winter vegetables that thrive in Irish gardens

Parsnips, celeriac, squash, Swiss chard and purple sprouting broccoli are happy to overwinter outdoors or wait out the colder months under cover

Swiss chard is surprisingly tolerant of winter cold, recovering quickly from low temperatures
Swiss chard is surprisingly tolerant of winter cold, recovering quickly from low temperatures

It was the writer Michael Pollan who noted that the garden is an unhappy place for the perfectionist. While I’m not the latter (too high a bar), still his words ring true. It’s why, when contemplating my kitchen garden efforts this year, I can’t help but feel a smidgeon of regret for the fact that I could have done better.

On the plus side, those vegetables that I did find time and space to grow did well. Tucked in between lines of cut flowers – a rough-and-ready version of an Irish potager – potatoes, mangetout, climbing French beans, beetroot, kale, lettuce, rocket and leeks all thrived, helped by a long, hot summer and a freshly opened soil rich in plant nutrients. But it’s now, as autumn descends, that I wish I’d grown more of the kinds suitable for eating/storing over winter.

Parsnips, for example, with their long, thick, edible, starchy root systems capable of happily sitting in the ground for months until needed. Indeed, their flavour is actually greatly enhanced by exposure to winter frosts – the trigger for a process where the plant converts the starch stored in its roots into sugar as a way of protecting it against damage from low temperatures. The happy byproduct of this natural vegetable antifreeze is parsnips’ distinctively sweet, nutty flavour, which has been celebrated since Roman times.

I love these root vegetables in a curried soup, or creamed, or roasted, but have yet to try making parsnip cake, even though the celebrated food writer Jane Grigson swore that it’s far superior to carrot cake. Those fleshy, sweet roots can also be used to make parsnip beer and parsnip wine.

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As for growing parsnips, it’s an exercise in patience, with germination of the direct-sown seeds (these should be sown in late spring) taking as long as a month. To reduce the risk of the disease known as canker, it’s important to choose a variety with good resistance such as ‘Gladiator’ or ‘Tender and True’. Parsnips can also fall victim to carrot fly so should be netted, while those long probing root systems also make them unsuitable for stony soils.

Another root vegetable happy to overwinter outdoors in an Irish garden is celeriac. The plain jane of the vegetable kingdom, its warty, whiskery flesh is packed full of flavour and partners perfectly with roasted bulb fennel but is equally delicious roasted on its own with lashings of butter and parmesan.

Just like parsnips, celeriac’s sweet, nutty, slightly aniseed taste is improved by exposure to winter frosts, so don’t be in a hurry to harvest it if you grew it this summer in your garden or allotment. But in wet gardens or those where slugs and snails are a problem, it’s best to lift it by late October and store the fleshy roots in a box of sand under cover of a garden shed.

Winter squash is yet another vegetable that’s perfectly suited to winter storage. This tender, heat-loving annual, a very close relative of the ornamental pumpkin, needs plenty of space (more than a square metre) for its fast-growing, rambling stems. Delicious used in a nourishing soup or roasted in fat slices with the golden flesh sprinkled with salt, olive oil and chilli powder, its large fruits will keep for many months just so long as they’re properly ripened and cured. These should be brought indoors under cover around this time of year before the first frosts hit and then stored in a cool, dry place.

Parsnips can be left to sit in the ground for months until needed
Parsnips can be left to sit in the ground for months until needed
Celeriac's sweet, nutty, slightly aniseed taste is improved by exposure to winter frosts
Celeriac's sweet, nutty, slightly aniseed taste is improved by exposure to winter frosts
Waltham butternut squash will keep for months after harvesting if properly ripened and cured
Waltham butternut squash will keep for months after harvesting if properly ripened and cured

Typically sown in late spring with gentle heat under cover and then planted out after all risk of frost has passed, varieties suitable for the vagaries of an Irish summer include ‘Waltham Butternut’, Uchiki Kuri’, and ‘Hunter’. Winter squash also does very well under cover of a polytunnel or glasshouse if you can give the plants the space they need.

Delicious home-grown autumn fruits you won’t find in the supermarketOpens in new window ]

As for Swiss chard, annoyingly I got as far as sowing seed this spring but then forgot to prick out the baby seedlings in time. This versatile, vigorous vegetable’s jewel-coloured, fleshy leaves are not only a beautiful addition to any potager style garden, but are also surprisingly tolerant of winter cold. Low temperatures will knock it back, but it recovers quickly and will overwinter in most Irish gardens, especially if given a protective mulch around the base of the plant.

In mild years, plants will continue to produce enough leaves throughout the winter months for the occasional harvest. Come spring, Swiss chard then bursts back into growth again, especially if plants are protected with horticultural fleece or a cloche. So, if you grew it this summer, make sure to leave it in the ground rather than summarily dispatching it too early to the compost heap.

If left in the ground, chard will produce enough leaves throughout the winter for the occasional harvest before bursting back into growth in spring
If left in the ground, chard will produce enough leaves throughout the winter for the occasional harvest before bursting back into growth in spring
Purple sprouting broccoli can tolerate temperatures as low as -15°C
Purple sprouting broccoli can tolerate temperatures as low as -15°C

Last on my vegetable list of regrets for 2025 is purple sprouting broccoli. A stalwart of the late winter/early spring garden with the ability to tolerate temperatures as low as -15°C, its tender, sweet, slightly peppery purple florets are a succulent treat chargrilled, or steamed and served with hollandaise sauce. This cut-and-come-again giant of the vegetable garden is also astonishingly productive, offering up multiple harvests from February right through to May.

Purple sprouting broccoli should be sown under cover in early summer, then pricked out and planted in the garden where it very slowly grows into a large plant. If, like me, you never got around to doing this, there’s still a chance of finding young container-grown plants in garden centres. Planted this month, they won’t be as productive as their summer-planted equivalents but are still worth the effort. Just make sure to net plants against pigeon damage, and to earth up around the plants’ root systems to help prevent them toppling in a winter storm as a result of root rock. In exposed sites, a very sturdy stake is advisable.

This week in the garden

Label dahlias before they finish flowering. In milder gardens where the plants will be left in the ground over winter, this helps to avoid accidental damage to their tubers when weeding/digging next spring. In colder, wetter gardens where the tubers will be lifted and stored over winter under cover, it prevents different varieties becoming mixed up.

Carefully collect, bag and dispose of any dead, damaged or decaying leaves, fruit and vegetables in the glasshouse and/or polytunnel to help prevent the spread of pests and diseases and keep plants productive.

Dates for your diary

Annual Apple Day Festival The Organic Centre, Rossinver, Co Leitrim; Sunday, September 28th, noon-4pm. Juicing demonstrations, talks and tours. See theorganiccentre.ie