Autumn frosts kill summer plants such as runner beans, tomatoes and cucumbers, but leave winter crops unscathed, allowing a new suite of vegetables adapted to Scotland’s colder climes to enter the gardening fray.
Many of these root vegetables are even thought to taste better after frost. The cold triggers the starch in them to break down and release glucose, which provides sweetness. The fact sugar freezes at a lower temperature than water means it acts like an anti-freeze and prevents the damage that frozen water causes in more tender plants.
A tough survivor is the neep, one of Scotland’s two most famous vegetables, though its Swedish origins give rise to it still being known by many as a swede. A love-it-or-loathe-it vegetable, the neep is accused of being dull by David Stuart in The Kitchen Garden, the author adding: “In the field, hares and pheasants are said to prefer swedes to turnips, not a taste I share. If you have only a small garden, it is probably not a culinary field worth investigating.”
I disagree. Even before being frosted, I reckon a neep has a delightful, if less pronounced flavour and, after a touch of frost, a stronger-tasting, sweeter neep also makes a tasty dish, and not just for St Andrew’s Day or Burns Night. Frosting changes the colour of the flesh, making it much darker. Vitally for me, the tough outer skin is pleasingly slug-proof.
Most other root vegetables -- carrots, parsnips, salsify and the less well-known scorzonera -- withstand the rigours of an average winter, and they too acquire a stronger, slightly sweeter flavour, almost excessively so in the case of parsnips. A borderline root -- one that will tolerate some but not too much frost -- is celeriac. Salsify and celeriac merit a place in any veg garden, so I recommend you add them to your seed order next year.
Meadow salsify or goat’s beard (Tragopogon pratensis) is native to the British Isles, but the salsify (Tragopogon porrifolius) we now grow originated in the Mediterranean, arriving in the 16th century. If you haven’t tasted this long, thin, almost asparagus-flavoured root, you’re missing something.
Salsify is grown much like parsnip, but you need to keep giving the plants a good drink throughout the growing season to stop the roots becoming hard and woody. Start harvesting the roots during October and November, and during very cold weather you could make this a shade easier by covering the ground with a mulch such as a thick layer of straw. Be warned, though: slugs will congregate there and tuck into your salsify before you. The similar-tasting scorzonera is grown in exactly the same way, but its thinner, more fiddly roots are much harder to deal with in the kitchen.
Celeriac is another massively underrated vegetable. Although it needs a steady, warm growing temperature in its early stages -- ideally 15C -- it will cope with the first few frosts. Unlike neeps and salsify, though, it’ll turn to mush in hard frost. When lifting, cut off and compost all the leaves and remove loose soil. Keep the roots in a cool, frost and vermin-free place. Layer the celeriac on damp sand in a solid wooden box, keeping each root apart from its neighbour. You could dig a trench to store the vegetables, but the thought of retrieving them in the middle of January might prove a deterrent to this approach. To exacerbate the problem, I have to stop rodents from consuming the lot, so I stick a box of celeriac in the large cupboard I use for storing apples.
The first frosts mark a change in the seasons and, for me, that means switching to winter fruit and veg. Parsnips are only for winter and courgettes and strawberries are for summer.