If you are harvesting celery now, you will be congratulating yourself because it is a very useful vegetable to have on hand. However, it is not a foolproof crop and if you do succeed in getting it to maturity without being stringy, slimy, disease ridden or slug infested, you often have the problem of excessive amounts of celery ready all at once. You can raise celery from seed but the need to stagger harvest means that most people will buy a few baby plants at a time from the garden centre. Seed is not such a great option when you only want 3 or 4 plants maturing at once. That said, I read one advisory that 16 to 20 plants per sowing (so we are talking successional planting) is sufficient for the average family. All I can say is that the author must have eaten vast amounts of celery.
Celery is a cool climate, very hungry crop. It needs good soil, preferably enriched with compost and rotted manure and you must keep it well watered in dry periods. Lack of water leads to stringiness and a bitter flavour. It is also a slow grower and can take up to four months to mature so you have to keep the food and water up to it for quite some time. In cold climates it is a spring crop, but in mild areas it can be sown or planted in early autumn as well. If you want to get a jump start on spring, you could sow seed soon into small pots and grow them under cover for planting out as soon as the soils start to warm up in September. Space at about 20cm apart and stay on top of the weeds which will compete with the celery’s root system and rob the nutrients.
First published in the Waikato Times and reprinted here with their permission.