A beginner's guide to growing celery

Celery is not an easy vegetable to grow. It needs more than the usual quantities of soil nutrients, a particularly well-prepared soil, and an abundant and never-failing supply of moisture. In addition, its tiny seeds are difficult to nurture into seedlings, even under ideal indoor conditions. So if you do raise a crop of this crisp and succulent vegetable, you will have won the right to consider yourself an accomplished horticulturist.

• Celery is usually started indoors in flats. Before sowing the seeds, soak them in water overnight to soften the seed coat.
• Use a light soil-and-sand mixture or sterile sphagnum moss as a growing medium, sprinkle the seeds into the pots, and cover with six millimetres of sphagnum moss.
• Keep the soil moist, and be patient — celery seeds take three weeks to sprout.When the seedlings are about three centimetres (one inch) tall, transplant them to individual pots.
• Do not transplant seedlings into the garden until they are at least eight centimetres (three inches) tall — a height they will reach 10 to 12 weeks after sowing.
• You can also buy seedlings from a local garden centre, which should have sturdy 15-centimetre (six-inch) plants available in time for early planting.

• Set out the seedlings when all danger of frost is past, or the plants may bolt. Count on at least 120 days of outdoor growing time for homegrown seedlings, 115 days for nursery plants.
• Because celery grows best in cool temperatures, much of that growing time should be in spring, when the weather is moderate.
• For years the classical method of planting celery was to dig a trench, set the seedlings at the bottom, and then heap earth around the stems as they grew.
• The earth helped conserve soil moisture and blanched the celery — that is, kept the stems white and tender by protecting them from the sun's rays.
• In recent times, however, celery strains have been developed whose sun-greened stalks remain tender and are also more nutritious than blanched stalks. "Self-blanching" varieties, with yellowish stalks, have also been developed. Most gardeners now plant celery in ordinary furrows.
• Trenching offers advantages even though blanching is not necessary: it protects late crops against frost, makes fertilizing easier, and eliminates the need for weeding.
• If you decide to use this method, dig a trench 35 centimetres (14 inches) wide and 25 centimetres (10 inches) deep, fertilizing, and filling with topsoil to a depth of 12 centimetres (five inches).
• Enrich the soil with plenty of compost or well-rotted manure. Prepare the soil at least two weeks before setting out your plants. Transplant on a cloudy day. Set the seedlings 15 to 20 centimetres (six to eight inches) apart in rows at least 60 centimetres (25 inches) apart, and water them in well with a compost tea solution.
• To protect against sun shock, cover the plants for the first few days with some form of shade, such as a floating row cover.
• Because celery is an exceptionally thirsty plant, mulch the soil heavily to conserve moisture and prevent weed growth.
• Keep the soil rich by watering around each plant with compost tea, diluted to half strength, every two or three weeks. Or apply a balanced organic fertilizer blend every two weeks, at the amount recommended on the product label.

Prevent fungal diseases, which cause yellow or brown spots on leaves and stalks, by drenching the soil with compost tea; by not planting celery in soil where it was previously grown; by not touching the celery plants when they are wet; and by keeping the bed free of weeds.

• If spots nevertheless appear, spray the celery plants with copper fungicide.

Growing celery can be difficult, but it's not impossible! Consider this guide before getting started and cultivate your celery the right way.