How to grow Celery in New Zealand

Where to plant

Grow celery in rich, moisture-holding soil with plenty of compost, in full sun or light shade and out of strong wind. It needs consistently moist soil to crop well; any stress gives dry, fibrous stalks.

• Northland, Auckland, Waikato and Bay of Plenty, Wellington, and Nelson and Marlborough: sow from August to October and February to April. In the warm north, leaf celery is the easier choice.
• Central North Island: skip August. Sow from September, covering young plants on frosty nights, and again from February to April.
• Canterbury: start in September under a cloche or frost cloth and keep sowing through to January with steady watering.
• Otago and Southland and Central Otago: sow from October to December, starting under a cloche. Skip autumn sowings, as growth stops before they are ready.

Choosing a variety

• Tall Utah: a reliable heirloom with crunchy, stringless stalks up to 75 cm and tight hearts that do not need blanching.
• Green Crunch and Tendercrisp: crisp salad celeries with long, stringless stalks.
• Cutting or leaf celery: a dwarf, intensely flavoured celery grown for its leaves and thin stems, ideal in pots and far easier than stalk celery.

How to plant

1. Sow seed thinly about 6 mm deep, or just pressed into the surface, in trays of seed raising mix. It is slow, taking 14 to 21 days.
2. Keep moist and warm until seedlings appear.
3. Transplant seedlings carefully with a little mix intact around the roots, as celery dislikes root disturbance. Space them 20 to 25 cm apart in rows about 60 cm apart.
4. Water in and mulch to keep the soil moist.

Watering and feeding

Water often, never letting the soil dry out. Celery is one of the thirstiest vegetables, and stress gives dry, stringy stalks or bolting.

Feed every week or two with a liquid fertiliser for leafy vegetables.

Pruning and care through the year

• To blanch stalk celery, wrap the stems in thick newspaper or black plastic from ground level to about 40 cm, three to four weeks before harvest. The stalks pale and are ready in 2 to 3 weeks. Self-blanching varieties such as Tall Utah do not need this.
• Keep slugs and snails away from young plants.

Harvesting

Pick outer stalks of green celery as needed, with a sideways pull to break them off at the base, so the plant keeps producing. For stalk celery, you can instead cut the whole head once the stalks are full size but still tender.

Leaf celery is ready in about 60 days; snip outer stems and leaves as needed. Celery keeps up to two weeks in the fridge in a sealed bag or wrapped in foil.

Growing in pots

Use a pot at least 30 cm wide and deep, in full sun and out of strong wind, filled with rich potting mix. Water very often. Cutting celery is the best choice for pots. Baby lettuce or microgreens can be sown around the edge, without overcrowding.

Using it

Eat celery raw with dips and in salads, or use it in soups, stews, stocks and stir-fries. The leaves have the strongest flavour and are good in soups.