How to grow Celeriac

• • Celeriac is a member of the Carrot Family, and it is recommended that it should not be grown in the same soil as other family members for at least three years.

  • Ideally, celeriac should not follow a crop from the Bean Family, as they fix large amounts of nitrogen in the soil, which can have an adverse effect on celeriac.

How to grow Celeriac - Soil preparation

• • They grow best in a soil which has been fertilised the previous season and not the current season.

  • Too much nitrogen in the soil from manure etc. will encourage leaf growth rather then growth of the bulbous root.

  • The best soil is one which retains moisture but is also free-draining.

  • Although those are the ideal conditions celeriac is very tolerant of soil conditions and will grow well on most sites.

  • They prefer a site which is in full sun but will tolerate part-shade very well.

How to grow Celeriac - Sowing seed

• • Celeriac takes longer than most vegetables to reach maturity and it also requires a soil temperature of at least 59°F if the seeds are to germinate.

  • If you live in a warm climate which has the correct soil temperature then the seed can be sown directly into the soil in early March and they will grow well.

  • Sow thinly at a depth of about ½ cm (¼ in).

  • As the seedlings emerge, gradually thin the seedlings to about 30cm (1ft) apart in rows which are 35cm (14in) apart.

  • In cooler areas, sow indoors or in a greenhouse / cold frame.

  • Sow two seeds to a small pot (7.5cm / 3in) in early March.

  • When the seedlings emerge, thin out the weakest growing one. The plants can be transplanted to their final positions in mid-May when the danger of frost is minimal.

  • Acclimatise the plants to the outside conditions for a week or two before planting outside.

How to grow Celeriac - Planting out

• • Plant out the hardened-off seedlings spaced to 30cm (1ft) in rows about 35cm (14in) apart.

How to grow Celeriac - Cultivation & care

• • Caring for celeriac is a simple matter. The plants grow strongly in most conditions.

  • When they are first planted outside, water frequently if the conditions are dry.

  • Once they are established, watering should not be necessary unless there is a prolonged drought.

  • Don't feed celeriac, the bulbous roots develop well enough if the initial soil conditions were correct.

  • Keep the plants weed free, frequent hoeing is the best solution.

  • In July and August you may notice side shoots starting to grow from the side of the now exposed root.

  • Pinch these out as they emerge because they do not contribute to increasing the size of the root.

  • By early September the roots will be swollen and visible above the ground.

  • Scoop up some soil surrounding the roots and cover the parts which are above ground. This will keep the roots whiter because they will not be exposed to sunlight.

How to grow Celeriac - Harvesting

• • Celeriac can be stored after harvest (see below) but the best roots are from plants which have been freshly dug up.

  • Celeriac will be ready for harvest around September time.

  • If your soil is free draining leave them in the ground and harvest as required.

  • A hard frost will damage them but they will withstand a light frost.

  • To protect them from frost a layer of straw or hay laid around the base of the plants will provide some insulation.

How to grow Celeriac - Preserving & Storing

• • If a hard frost does threaten then lift the plants.

  • Cut off the top foliage and store in boxes of slightly damp peat in a cool greenhouse or shed.

  • With the correct treatment you can be eating celeriac up until late March.