If you like the taste of celery, but find it a little cumbersome, then celeriac is the vegetable for you. Celeriac has a similar flavour to celery, but is grown for its knobbly, turnip-shaped swollen stem. As vegetables go, it’s ugly as sin, but don’t let that fool you – it tastes delicious. It’s very hardy and (unlike celery) stores extremely well. A decent crop of celeriac can see you right through the winter months to late March. Celeriac is also referred to as knob celery or turnip rooted celery.
Grow celeriac as you would with celery, but because it stores well, there’s no need for succession sowing. A single sowing in late March or early April is all that’s required. Broadcast (sprinkle liberally) the seed in to a pot filled with compost. As is the case with celery, celeriac seeds need light to germinate so do not cover the seed with compost. Place the pot somewhere warm (a sunny windowsill or a heating mat) – it’s slow to germinate so don’t expect any action for two to three weeks. Keep the compost moist. Prick the seedlings out in to module trays (one seedling per module) about 2 weeks after germination (when about 3cm tall). If you grow 24 celeriac you can enjoy one a week from October to the end of March. You will need 1m of veg bed for every 9 celeriac (where the bed is 1.2m wide).
Dig the bed where you are going to grow celeriac in the winter or early spring and add plenty of well rotted manure or compost. After hardening off well, plant out the seedlings in to the bed in May or when the seedlings are 10cm tall. Space the plants 35cm x 35cm apart. Celeriac is shallow rooting which means two things – firstly it will dry out easily so you will need to water well in dry weather (and/or mulch around the plants to conserve moisture). Secondly you need to be careful when hoeing in case you damage the roots.
Celeriac are ready to rock from October onwards. They can be left in the ground in a mild winter (though they can be a little vulnerable to worms etc which will bore inside) or lifted and stored in sand. Use a fork to gently lift the plant, roots and all.
It’s a healthy veg, so not much will bother it if you follow the guidelines above. Slugs like the seedlings however.