How to grow celeriac on the allotment

A close relative of celery, celeriac has a subtle nutty, aniseed flavour. It is usually considered to be a root crop but the edible part is actually a swollen stem. It originates from the Mediterranean and although quite hardy once established immature plants are tender and need careful management at first.

Celeriac can be served mashed, roasted or in soups and stews as well as grated raw in salads. It’s one of the most versatile vegetables on the allotment.

Sow celeriac

If you are familiar with the large knobbly-rooted celeriac but have never grown it before you may be surprised by how tiny the seeds are and how spindly the seedlings are at first.

Celeriac can be sown in a heated propagator from February or in the greenhouse or on a window sill from March until April. Germination can be inconsistent and a temperature of around 15 to 20 degrees centigrade is required. They require a long growing season so best results are usually to be had from early sowing in a propagator.

I sow thinly in small cells of general purpose compost and cover with 1 cm of compost. Water by standing the seed tray in a container of water as there’s a danger that watering from above with a watering can will wash the seeds away. Germination takes 14 - 21 days.Thin to one seedling per cell once they begin to develop.

Transplant to 5 cm pots when large enough enough to handle.

Grow celeriac

Grow on in their pots in slightly cooler, but frost free conditions, potting on into larger pots if it becomes necessary. Do not allow to dry out.

Plant out into the allotment in May or June. Give them plenty of space, about 30 cm in each direction is ideal. They like a rich, moisture retaining soil so add well rotted manure or garden compost if you have it. Water regularly.

As the plants grow the outer leaves will drop, these should be removed. This helps the bulb develop, allows good air circulation and light around the plants. It also denies slugs, snails and other pests the cover the leaves would otherwise provide.

Continue to water generously throughout the growing season.

Harvest celeriac

Celeriac will be ready to harvest from October until March. Cover with mulch to prevent frost damage. They will also keep well in a refrigerator. For best results remove the foliage and store in a plastic bag in the vegetable compartment.

Celeriac problems

Celery leaf miner causes brown blisters on the foliage. Remove and burn any affected leaves. Can be prevented by covering with fine mesh.

Slugs and snails may attack immature plants.