How To Grow Celery: 7 Helpful Tips

Growing celery in your home garden comes with numerous benefits. Homegrown veggies always taste better than store-bought ones. You’ll also have the peace of mind that comes with knowing your celery hasn’t been treated with harmful pesticides and other chemicals. Keep reading to learn how to grow celery plants and keep them thriving until harvest time.

Celery is a cool-weather vegetable and has a long growing season. The average time between planting seeds and harvest is around 80-130 days, depending on the variety. Therefore, most gardeners start celery seeds indoors in late winter or early spring, approximately six to ten weeks before the zone’s average last frost.

For a fall crop, plant celery seeds 12-14 weeks before your average first frost date. If daytime temperatures are still over 80℉, it’s best to start the seeds indoors and transplant your seedlings when the weather cools.

Despite having a reputation for being difficult to grow, planting celery in your veggie garden is worth the effort. Are you ready to start growing your own groceries? Let’s dig in!

How to Grow Celery Plants

Celery (Apium graveolens) is naturally a biennial plant. The plant grows leaves, stems, and roots in its first year. The following season, it produces flowers and seeds. However, most gardeners grow celery as an annual crop to harvest crisp stalks.

There are two primary kinds of celery plants: self-blanching and trenching. Trenching celery varieties undergo a period of light deprivation to produce paler, sweeter, more tender stalks like those in the grocery store. In contrast, self-blanching celery doesn’t undergo light deprivation.

The advantage of blanching celery is removing the bitterness from the stalks. However, depriving the plant of chlorophyll reduces vitamin content. To blanch a celery plant, gradually mound the soil around its base once it reaches about 12 inches tall. Gradually keep mounding more soil, adding two or three inches every few days until the mound is almost up to the leaves. Another option is wrapping the plant in cardboard or thick paper for two to three weeks before harvest.

Best Varieties of Celery

• Conquistador (hybrid, trenching, drought-tolerant, heat-resistant, 18-24 inches tall, 80-115 days to maturity)
• Giant Red (heirloom, trenching, reddish-purple stalks that turn pink when cooked, cold-hardy, 20-24 inches tall, 85-120 days to maturity)
• Golden Pascal (heirloom, self-blanching, stringless, cold-hardy, 18-24 inches tall, 115-140 days to maturity)
• Golden Self-Blanching (heirloom, self-blanching, disease-resistant, 25-30 inches tall, 105-130 days to maturity)
• Tall Utah (heirloom, trenching, stringless, disease-resistant, 24-30 inches tall, 100-125 days to maturity)

Celeriac, also called knob celery or Apium graveolens var. rapaceum, is a celery variety cultivated for its large, round, edible root. It’s a rich source of vitamins, minerals, and fiber. Celery root can be mashed, roasted, baked, boiled, or eaten raw.

How To Grow Celery from Seed

Begin by filling a seedling tray, peat pots, or a cardboard egg carton with nutrient-rich potting soil. Cover the seedling tray with a humidity dome or sheet of plastic wrap to hold in moisture. It’s helpful to pre-saturate the soil to avoid disturbing the seeds after planting.

Plant three or four celery seeds per cell, and don’t press them down or cover them. Celery seeds are tiny, but it’s best not to plant more than four seeds together. Otherwise, the seedlings become stunted from growing too close together. Dip a damp cotton swab into the seed packet to better control seed dispersal and scrape them off using a toothpick.

Celery seeds usually germinate in one to three weeks. To speed up germination, soak the seeds in lukewarm water overnight before planting them to break down their protective outer coating.

The optimal soil temperature for germinating celery seeds is 70-75℉. For best results, use a heat mat to keep the soil consistently warm during germination and while the seedlings develop.

How to Grow Celery Seedlings

Once your celery seedlings sprout, move them to a sunny windowsill that gets at least six hours of direct sunlight daily. If you don’t have a south-facing window available, consider using a grow light to prevent the seedlings from growing elongated or “leggy.” Encourage strong stem growth by rotating the tray every few days.

Once the seedlings are two inches tall, transplant them into 4-inch pots. They grow best at temperatures around 70-75℉ during the day and 60-65℉ at night. Keep the soil consistently moist but not soggy.

When to Transplant Celery Seedlings Outdoors

Begin to harden off your celery seedlings about two weeks before transplanting them into your garden. Set them outside in a sheltered area for progressively longer periods each day to acclimatize them gradually. Doing so helps to avoid transplant shock.

The best time to transplant celery seedlings outdoors in most areas is one week after your average last frost date. The soil temperature should be at least 50℉, with nighttime temperatures consistently above 40℉.

Celery Growing Tips

Celery plants grow best with full sun, plenty of water, and soil rich in organic matter. Add several inches of organic compost to your garden bed a week or two before transplanting.

For growing blanching celery varieties using the mounding method, plant your seedlings in twelve-inch deep trenches. If you’re planting self-blanching celery, trenching isn’t necessary.

Add two tablespoons of organic, all-purpose fertilizer to the bottom of your planting hole. Then, fill in around the sides of the root ball with a mixture of soil and compost.

Used coffee grounds and eggshells make an excellent natural mulch that helps deter slugs. Eggshells add calcium to the soil when they decompose, and coffee grounds supply nitrogen. Fertilize celery plants once per month throughout the growing season.

Celery stalks often become withered and stringy if they dry out too much. On average, give celery plants 1 to 2 inches of water per week or more in hot or dry weather. Use bark chips, grass clippings, leaves, pine needles, or straw as mulch to retain moisture, suppress weeds, and keep the roots cool.

Harvesting Homegrown Celery

Harvest self-blanching celery stalks as needed from the outside of the plant. Or, cut the whole plant at once. Blanching celery should remain covered for two to three weeks before harvest.

Celery planted in the spring is ready to eat in late summer. A fall crop matures in late autumn to early winter.

Always use a clean, sharp knife or pair of pruners when harvesting celery. Sterilize your tools before and after each use to avoid accidentally spreading diseases between plants.

Celery leaves are also edible and provide a robust flavor similar to anise or fennel. The light green inner leaves taste milder and have a tender texture, making them excellent for using as a garnish or eating raw in salads. Cook the dark green outer leaves in soups, stews, and sauces.

Companion Plants for Celery

Companion planting utilizes plants’ unique properties to repel pests, attract beneficial insects, and enrich the garden ecosystem. However, certain plants aren’t compatible and must grow separately.

Aromatic herbs like oregano, dill, rosemary, sage, and thyme attract pollinators and beneficial predatory insects. In addition, they also repel common garden pests like aphids, cabbage loopers, whiteflies, and spider mites, as well as deer and rabbits.

Allium plants like chives, garlic, and onions repel insect pests, rodents, and deer. These plants also give celery a sweeter flavor when grown close by.

Geraniums and nasturtiums repel cabbage loopers, celery worms, and flea beetles. These flowers can also be trap plants for aphids to deter them from feeding on celery plants.

Celery is a helpful companion plant for brassicas like broccoli, cabbage, kale, radishes, and turnips, in addition to bush beans and cucumbers. Celery plants repel whiteflies and cabbage moths.

Keep celery away from carrots, parsnips, and parsley. Since they’re in the same plant family as celery, they’re prone to similar pests and diseases. In addition, they’ll compete with celery for the same nutrients and root space.

Common Pest and Disease Problems

The most common celery pests are aphids, cabbage loopers, celery worms, slugs, and spider mites. If you notice insect damage on the stalks or leaves, spray the entire plant with insecticidal soap or neem oil. Protect your seedlings with row covers or a cold frame after transplanting.

Leaf spot is one of the most prevalent fungal diseases for celery plants. First, yellow patches form on the leaves that later darken to brown or grey. Spores typically spread via splashing water, insect activity, and contaminated garden tools. Treat leaf spot fungus with a copper fungicide after removing the diseased plant matter, and sterilize your pruners afterward.

Don’t add plant material affected by pests or diseases to your compost. Insect eggs and fungal spores can overwinter in compost. To avoid disease problems, water with drip irrigation, and clean your tools between uses. To learn more about pest and disease control for celery plants, check out this article from Pennsylvania State University’s PlantVillage.

Homegrown celery tastes better and is more nutritious than the store-bought alternative. Grow celery in an area with full sun, good drainage, and nutrient-rich soil.

Have you ever tried growing celery? Share your success stories or ask any questions you may have in the comments below! If you enjoyed learning how to grow celery, please share this article with your fellow gardeners.