For centuries, aromatic celery has flavored soups and added crunch to salads. But today’s commercial, non-organic celery continuously ranks near the top of the list of vegetables known to carry chemical residues, with some samples tainted with more than 60 pesticides.
That’s a great reason to buy organic or start growing celery yourself, cutting celery and celeriac — three different forms of celery’s parent species, Apium graveolens. Native to Greece, celery is easy to grow if given a long head start indoors and rich, moist soil.
Celery Types to Try
Stalk celery is the supermarket version most people recognize. Commercial stalk celery is grown by following an intricate regimen of fertilizers and flood irrigation. Even under perfect growing conditions, stalk celery stays in good picking condition for only a few days. If you're growing celery in moist garden soil, stalk celery can be handled as a cut-and-come-again crop — just harvest a few outer stalks at a time.
Cutting celery is like a primitive form of stalk celery. The bushy plants produce numerous small stalks with strong flavor. Established plants are hardy to Zone 5 or 6. Cutting celery that survives winter will bolt in spring and produce heavy crops of edible seeds, and it will reseed itself with slight encouragement.
Celeriac slowly develops a rounded, knobby root that has a crisp texture and mild, nutty flavor. While in the ground, you’ll see thin, celery-like stalks growing from the rounded top of the edible root. Celeriac harvested in fall will store for weeks in a cold root cellar or refrigerator.
For more information about types of celery and our recommended varieties, see our Celeries at a Glance chart.
When to Plant Celery
Celery seeds of all types are small and may germinate erratically. Start them in doors or in a greenhouse 10 to 12 weeks before your last spring frost and give them bright light. Seedlings that have more than five leaves can be hardened off and set out when average night temperatures are above 55 degrees Fahrenheit. Exposure to cold for more than a week can trigger plants to bolt and produce seeds. In hot summer areas with mild winters, start seeds indoors in late summer and set them out in early fall. Plants should be ready to harvest about 90 days after you put your seedlings in the ground.
How to Plant Celery
Choose a sunny site that is convenient to water, because celery requires constant moisture. If possible, allow space between rows for a shallow trench that can be flooded with water in dry weather. Dig in a 1-inch layer of rich compost and a standard application of a high-nitrogen organic fertilizer, such as dried poultry manure, and water well. Wait at least three days before planting seedlings 12 to 14 inches apart. Before hot weather comes, mulch between plants with grass clippings or another organic mulch to keep the soil cool and moist.
Growing Celery: Tips and Tricks
Celery and celeriac seedlings should show vigorous new growth a few weeks after they have been transplanted. Plants that are making little progress should be drenched with fish emulsion or another organic liquid fertilizer. Try to keep the plants’ roots moist at all times, and don’t worry about excessive rain — celery and celeriac tolerate waterlogged soil better than other vegetables.
To encourage stalk celery to develop a pale, mild-flavored heart, use an elastic hair scrunchie or strips of soft cloth to secure the stalks into a bunch after the plants have been growing in the garden for eight to 10 weeks. Blanching — excluding light from the stalks to prevent chlorophyll production — for one to two weeks is necessary to grow celery that looks lighter and tastes milder (think supermarket celery).
Harvesting and Storage
Cut high, 1 to 2 inches from the ground, when harvesting celery hearts. A new stalk (and sometimes two or three) will sprout from the stump left behind. Trim off excess leaves and tough outer stalks before storing celery in the refrigerator. Freeze blemished celery and the outside stalks that are dark and coarse for flavoring broths and stocks. Include bits of celery or cutting celery in packets of frozen garden veggies. Blanch and dry a bumper crop of stalk celery or cutting celery. Dried celery makes a great addition to homemade soup mixes.
Celeriac plants shed their lowest, oldest leaves naturally beginning in midsummer. Low, hollow stems in good condition can even be used as novel drinking straws. Harvest celeriac before hard freezes damage the roots. Clip off all leaves and roots before storing celeriac in the refrigerator or packed in damp sand in your root cellar.
Celery is a biennial plant capable of producing large amounts of seed for eating and replanting in climates where plants survive winter (Zones 5 and 6, depending on exposure). Cutting celery in particular will reseed itself to become a welcome volunteer crop. To grow a crop of celery seed, lightly mulch over the crowns of 1-year-old plants in early winter, after they have been killed back by cold. Or, protect them with a dome or tipi made from scraps of row cover. Remove mulch or covers in early spring, and allow the plants to grow until they produce tiny white flowers followed by dark brown seeds. Collect seed-bearing stems in a paper bag and allow them to dry indoors for a few days. The ripe seeds will accumulate at the bottom of the bag.
Celeriac seed can be grown this way as well, or you can start seeds indoors in late winter and set out the plants under row covers while the weather is still cold. Exposure to cold triggers bolting, making it possible to grow a seed crop of celeriac (or other celery) in one growing season.
Final Recommendations for Growing Celery
Commercial celery crops suffer from a long list of insect and disease problems, but garden celery is often trouble-free when grown in rich, moist soil. Be sure to rotate celery with unrelated vegetables to prevent the buildup of soilborne diseases that flourish in wet soil.
Stems that seem dry and have hollow channels did not receive enough water. The best crops come in rainy years. Celery and celeriac benefit from frequent drenches with a liquid organic fertilizer.
In the Kitchen
Low in calories yet high in fiber, celery is a good source of vitamins A, C and K. Chop stalk celery into salads, soups and main dishes to impart flavor and texture. You can do the same with cutting celery by choosing young stalks and cutting them into small pieces. If any garden celery tastes so strong it’s almost bitter (a side effect of strong sun), blanch pieces for a minute or two in boiling water before adding to cooked dishes. Peel celeriac with a sharp knife, and cook the nutty flesh like potatoes. If you’ve never tasted celeriac, you’ll become a devotee after you’ve sampled it braised in butter with a little salt.
If you buy organic celery, immediately cut off the bottom inch of the bunch and plant it to half its depth in a pot of moist soil. By the time you have used the celery you bought, a small new bunch of two or three stalks should appear in the pot. Harvest it when they are about 8 inches tall, because the minimally rooted base won’t be able to support a full-sized plant. Trimmed celery stalks will keep for weeks in the refrigerator if wrapped in aluminum foil.
Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.