Celery in Zone 6B — Great Plains

Homegrown celery has a taste you just can't find in the grocery store, and it's a versatile addition to soups, salads, and snacks. Plus, there's something deeply satisfying about coaxing this cool-weather crop through our Great Plains summers. Celery can be a bit of a challenge, but the reward is worth it.

We all know our region can throw some curveballs with extreme temperature swings, wind, and variable rainfall. But with a little planning and attention to watering, you can definitely grow celery here. Our growing season is around 198 days, so timing is key.

Start your celery seeds indoors from late January through mid February, giving them about 10 weeks to get a head start. You'll need seed trays, a warm spot (around 70-75°F), and a good grow light, since our spring weather can be pretty variable. A heat mat can really help with germination.

Celery seeds are tiny and need light to germinate, so don't bury them too deep – just sprinkle them on the surface of your seed starting mix and gently press them in. Keep the soil consistently moist, and bottom watering can be a great way to avoid disturbing the delicate seedlings. Be patient; they can be slow to get going.

Transplant your celery seedlings outdoors from early April through early May, after the risk of hard frost has passed. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the wind and temperature fluctuations that are common here on the Plains.

Space your celery plants 8-10 inches apart in a spot that gets full sun to partial shade. Choose a cloudy day for transplanting, if possible, to minimize transplant shock. Water them in well immediately after planting. Keep an eye on the forecast; a sudden cold snap can set them back.

Celery is a thirsty plant, and consistent watering is absolutely crucial for success in our Great Plains climate. We often deal with hot summers and variable rainfall, so you need to be vigilant. Celery needs consistently wet soil.

Aim to water deeply at least 1-2 times per week, providing about 1-2 inches of water each time. Use the finger test: stick your finger about 2 inches into the soil. If it feels dry, it's time to water. In the hottest part of the summer, you might need to water even more frequently. Watering at the base of the plant is ideal, especially with our low-to-moderate humidity, to avoid fungal diseases.

Signs of underwatering include wilting leaves and bitter-tasting stalks. Overwatering, on the other hand, can lead to root rot. A layer of mulch around your celery plants can help retain moisture and regulate soil temperature, which is especially helpful given our extreme temperature swings.

You can expect your first celery harvest from early July through late August, about 85 days after transplanting. Look for outer stalks that are at least 8 inches long. You can harvest individual stalks as needed, or cut the entire plant at the base when the stalks are 12+ inches.

To harvest individual stalks, simply cut them off at the base of the plant with a sharp knife. This allows the inner stalks to continue growing. If you prefer milder celery, try blanching the stalks by mounding soil around them a week or two before harvesting. As the first frost approaches in late October, harvest any remaining celery.

Bolting from Temperature Stress

• What it looks like: The plant sends up a flower stalk prematurely, and the celery stalks become bitter and tough.
• What causes it: Extreme temperature swings, especially a sudden shift from cold to hot, can trigger bolting. This is common in our region with its unpredictable spring and early summer weather.
• How to fix/prevent it: Choose bolt-resistant varieties. Provide consistent watering to reduce stress. Use shade cloth during periods of intense heat. Consider a cold frame or row covers during cooler periods.

Hollow Stalks

• What it looks like: The inside of the celery stalk is empty or has a large air pocket.
• What causes it: Inconsistent watering and nutrient deficiencies, especially calcium. Our variable rainfall can make it difficult to maintain consistent soil moisture.
• How to fix/prevent it: Water deeply and regularly, especially during dry spells. Amend your soil with compost before planting to improve nutrient availability. Consider adding a calcium supplement to the soil.

Stringy Stalks from Heat

• What it looks like: The celery stalks are tough and fibrous, making them unpleasant to eat.
• What causes it: Prolonged exposure to high temperatures. Our hot Great Plains summers can definitely contribute to this problem.
• How to fix/prevent it: Plant in a location that gets partial shade during the hottest part of the day. Ensure consistent watering. Choose heat-tolerant varieties. Harvest before the hottest part of summer if possible.

Great Plains Specific Challenges: Our hot summers, low-to-moderate humidity, and variable rainfall make growing celery a real test. Consistent watering is absolutely essential, as is protecting your plants from extreme temperature swings. Mulching and providing shade during the hottest part of the day can also help.

Celery benefits from companion planting. Green beans help by fixing nitrogen in the soil, which celery needs for healthy growth. Cabbage deters some common celery pests, like the cabbage white butterfly. Tomatoes provide shade during the hottest part of the day, and their strong scent can confuse pests. Onions also deter pests with their strong odor.

Avoid planting celery near carrots. Carrots and celery both attract the same pests, which can increase the likelihood of infestation.