Celery in Zone 7A — Midwest

Celery might seem like a grocery store staple, but homegrown celery in the Midwest has a flavor you just can't beat. The crisp, aromatic stalks are fantastic in soups, salads, and as a healthy snack – and knowing you grew it yourself in our fertile soil is extra rewarding. Plus, it thrives in our summer heat, giving you a productive harvest.

Yes, Midwest weather can be unpredictable, and celery needs a long growing season. But by starting seeds indoors and timing your transplant carefully, you can absolutely enjoy a delicious celery harvest within our 193-day growing season.

Starting celery indoors is essential here in the Midwest, given our moderate-to-late spring. You'll want to sow those tiny seeds late January through mid February, roughly 10 weeks before you plan to move them outside. Use seed trays with a good seed-starting mix, and remember celery seeds need light to germinate, so don't bury them too deep – just gently press them onto the surface.

Keep the trays consistently moist; bottom watering is a great trick to avoid disturbing the delicate seedlings. Provide warmth and plenty of light, either with a sunny windowsill or grow lights. Celery can be slow to get going, so be patient and don't get discouraged if it takes a little while to sprout.

Transplanting time arrives early April through early May, after the danger of hard frost has passed. Before planting them in the garden, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Midwest weather and prevents transplant shock.

Plant your celery seedlings 8-10 inches apart in well-prepared soil. Keep an eye on the forecast – late frosts are always a possibility in the spring, so be ready to cover your young plants if needed.

Celery is a very thirsty plant, and consistent moisture is key to preventing bitter, hollow stalks. In our Midwest climate, with its moderate-to-hot summers and moderate-to-humid air, you'll need to pay close attention to watering.

During the hotter parts of the summer, aim for at least 1-2 inches of water per week, either from rainfall or irrigation. Stick your finger about 2 inches deep into the soil – it should feel consistently moist. Water at the base of the plants to avoid wetting the foliage too much, which can encourage fungal diseases in our humid environment.

Wilting leaves are a sign of underwatering, while yellowing leaves might indicate overwatering. A layer of mulch around your celery plants will help retain moisture and keep the soil cool, which is especially helpful during those summer heat spells.

You can expect your first celery harvest early July through late August, about 85 days after transplanting. Start harvesting individual outer stalks when they're at least 8 inches long. For a larger harvest, you can cut the entire plant at the base when the stalks reach 12+ inches.

Harvesting the outer stalks encourages continued production throughout the summer. If you prefer a milder flavor, blanch the stalks by mounding soil around them a week or two before harvesting. As our first frost approaches in mid- October, harvest any remaining celery to enjoy before the cold weather sets in.

Celery can face a few challenges here in the Midwest, but knowing what to look for can help you keep your plants healthy. The top three problems we see are bolting from temperature stress, hollow stalks, and stringy stalks from the heat.

Bolting from temperature stress

• What it looks like: The plant prematurely sends up a flower stalk, and the stalks become bitter and tough.
• What causes it: Fluctuations in temperature, particularly cold snaps followed by warm weather, can trigger bolting. This is common with our variable spring weather here in the Midwest.
• How to fix/prevent it: Choose bolt-resistant varieties and provide consistent temperatures. If a cold snap is expected, protect your plants with row covers or move them to a sheltered location.

Hollow stalks

• What it looks like: The inside of the celery stalks are hollow and air-filled.
• What causes it: Inconsistent watering and nutrient deficiencies are the main culprits. Celery needs consistently moist soil, especially during our summer heat spells.
• How to fix/prevent it: Water deeply and regularly, and fertilize with a balanced fertilizer. Make sure your soil is rich in organic matter.

Stringy stalks from heat

• What it looks like: The celery stalks are tough and fibrous, making them unpleasant to eat.
• What causes it: High temperatures can cause celery stalks to become stringy.
• How to fix/prevent it: Provide afternoon shade during the hottest parts of the summer. Consistent watering also helps.

Midwest Specific Challenges: Our moderate-to-hot summer heat, combined with moderate-to-humid humidity and wet-summer rainfall, means you'll need to be extra vigilant about watering and providing adequate shade for your celery plants. Consistent moisture is key to preventing many of these problems.

Companion planting can give your celery a boost in the Midwest garden. Green beans are great companions because they fix nitrogen in the soil, which celery loves. Cabbage family plants also do well with celery, as they can help deter some pests. Tomatoes and onions are good choices too, as their strong scent can confuse pests that might otherwise target your celery.

Avoid planting carrots near celery. Carrots and celery compete for the same nutrients in the soil.