Celery plants (Apium graveolens) grow spicy-flavored foliage and crisp stalks that are used fresh or in cooked entrees and soups. Instead of buying celery in the grocery store, grow fresh celery in your backyard garden. Though celery is very finicky when it comes to weather and temperatures, anyone can provide the plant with the basic care it needs to thrive and produce a bountiful harvest.
Fill a seed tray with standard potting mix. For the best results, use a tray that's 3/4 to 1 1/4 inches deep, according to North Carolina State University.
Plant the celery seeds, burying one seed in each individual socket in the seed tray. Bury the seeds 1/4 inch under the soil surface.
Sprinkle the seed tray with water twice a day or as needed to keep the potting soil moist. The seeds will typically germinate within 14 days.
Prepare the outdoor garden soil while waiting for the celery seeds to grow. Use a spade to break up the dirt to a depth of 6 to 8 inches. Stir in 4 inches of aged compost or manure to boost the soil's ability to retain both moisture and nutrients. Fertilize the area with a basic 16-16-8 fertilizer at a rate of 1 lb. for every 50 square feet of gardening space, according to Utah State University.
Transplant the celery seedlings into the garden soil once they've grown three or four leaves, according to Utah State. N.C. State recommends spacing each transplant by 7 to 10 inches.
Water the celery plants. They develop shallow root networks that require frequent watering--apply twice a day and expect to use approximately 1.5 inches of water per week per plant, according to N.C. State. Insufficient watering will create stringy, bitter celery plants.
Fertilize the celery plants twice before harvesting. Utah State recommends spreading a 16-16-8 fertilizer approximately six weeks after transplanting at the rate of 1 lb. for every 50 square feet of soil. Fertilize again four weeks later with a high-nitrogen 46-0-0 fertilizer at a rate of 1/2 lb. for every 100 square feet.
Control celery plant pests. Common insect pests include aphids and leafminers, according to the University of Florida. A basic insecticidal spray labeled for use on vegetables will effectively control such problems.
Harvest the celery. The stalks are ready for harvesting when they're approximately 12 inches long and 3 inches in diameter. Uproot the plants and trim off the roots. Celery can be stored in a refrigerator for up to 14 days.