The wild plant grows in marshy, salt impregnated ground in several parts of the world. The cultivated form needs a long growing season in the North of the UK. Therefore it is probably best sown with a little heat in cells, then transferred to a cold frame before being transplanted to the final growing position in May. I always look forward to eating the inner stems in salads.
Warning. Apparently, some people can develop potentially fatal allergic reactions to raw celery and even cooked celery.
There are two basic different types of celery available, the so-called self-blanching type and the trench type of celery.
The self-blanching type of celery is not frost hardy, and even with cloche protection it does not take much frost to make the leaves and stems turn to mush. It should be ready in about 6 months from sowing.
The trench type of celery is claimed to be much more hardy, with the stems protected with cardboard or paper and covered up with soil. It should be ready in about 10 months from sowing.
Sow the seeds in individual cells, with a little heat in February or March and harden off in a cold frame. Plant out the seedlings about 30 cm apart in May in their final positions, with cloche protection in case of night frosts. Keep the young plants well watered especially in dry weather to prevent the stems becoming tough and stringy. Remember that the wild form of celery grows in marshes, so it likes moisture.
When growing self-blanching celery, plant the seedlings 22 cm apart, in blocks so that the plants shade each other and aid the blanching process.
If growing the trench type of celery, when planting out the seedlings at 22 cm spacing in their final positions, place them at the bottom of a 10 cm deep trench. Allow the young plants to grow till August in the open trench. At this stage, wrap the stems with cardboard or newspapers. Then infill the trench with soil to below the height of the cardboard, just leaving the tops showing.
Self-blanching celery. Loretta.
Trench celery. Hopkins Fenlander.
Pests and diseases. Slugs and snails seem to be particularly fond of celery. It is very bad in the Autumn when the slugs get in between the celery stems and cause a lot of damage. Try slug pellets to prevent damage. Apparently, carrot fly can cause damage but I have never seen it.
Storage. Will keep in the fridge crispator for several weeks.
Celery leaves are also nutritious (vitamins and minerals C, magnesium, calcium) and can be eaten when added to a salad, stir fry, soups and stews, and as a garnish for fish and chicken. Do not add too much as they can taste bitter when the leaves are older.