|Celery (Apium graveolens) Photo Credit|
Celery is not a common northern garden addition because it needs a very long, cool, growing season (the long growing season being the limiting factor) but starting it indoors can give the extra time it needs. Start celery indoors 10 - 12 weeks prior to the average last spring frost and transplant it into the garden about one week before the last frost, or root the bottom end of a purchased celery plant. Celery does not like hot temperatures and needs 125 growing days or more to reach maturity. Getting it started early in the spring is essential both to give it the time it needs and to keep it cool. Plant individuals about 8 inches apart and slightly deeper than they were in the container they were started in.
Celery is a heavy feeder and benefits significantly from additional applications of garden fertilizer (10-10-10), or a rich compost several times during the growing season. It also has a shallow root system and is susceptible to drying out which causes tough, stringy stalks, or even, heart rot. It is very important to maintain even moisture for the plant to survive and produce a quality product. Stabilize moisture in the root zone by applying a thick layer of mulch around the plants after they have reached about 6 inches tall, and closely monitoring the soil moisture in the top 2 inches.
Some varieties of celery require the stalks to be blanched to keep them from getting a dark green color and bitter tasting. Blanching is basically removing the stalks from sun exposure. The easiest way to blanch celery is to place a paper milk carton sleeve around it, or wrap a paper bag around the plant and tie it on.
Harvest outer stalks anytime after the plant reaches 6-8 inches tall for immediate use or the whole plant can be harvested and stored in a dry cool location for 2 or 3 weeks. Plants will tolerate a light frost but should be harvested before a hard frost in the fall.
Happy Gardening! :)