Celery in Zone 7A — Desert Southwest

Growing celery in our Desert Southwest gardens can be surprisingly rewarding. The crisp, refreshing flavor is far superior to what you find in stores, and it adds a unique dimension to soups, salads, and snacks. Plus, the satisfaction of coaxing this water-loving plant to thrive in our arid climate is a real accomplishment.

Sure, celery needs a bit more attention than some other crops, especially with our extreme heat and alkaline soil. But with careful timing and consistent watering, you can enjoy a delicious harvest. Our long 230-day growing season gives us a good window to make it happen.

Start your celery seeds indoors in early to late January, about 10 weeks before the last expected frost. You'll need seed trays or small pots, a good seed-starting mix, and a warm, bright location. Celery seeds are tiny and need light to germinate, so don't bury them too deeply – just barely cover them with soil.

Keep the soil consistently moist, but not soggy. Bottom watering can be helpful to avoid disturbing the delicate seedlings. Remember, our spring warmth comes early here in the Desert Southwest, so getting a head start indoors is essential for a successful harvest.

Transplant your celery seedlings outdoors in late March through late April, once the danger of frost has passed. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the stronger sun and wind we often experience.

Space your celery plants 8-10 inches apart in a well-prepared bed. At transplant time, the weather can be unpredictable, with temperature swings. Protect the seedlings from sunburn with shade cloth if necessary.

Celery is one of the thirstiest vegetables you can grow, and consistent watering is absolutely critical for success in our Desert Southwest climate. You need to keep the soil consistently moist, especially during our hot, dry summers. Even a brief dry spell can lead to hollow, bitter stalks.

During the spring and fall growing seasons, aim to water deeply 2-3 times per week, providing about 1-2 inches of water each time. During the extreme heat of summer, you may need to water daily, or even twice a day, to keep the soil consistently moist. Use the finger test – if the top 2 inches of soil feel dry, it's time to water.

Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our monsoon season. Mulching around the plants with organic matter will help retain moisture and keep the soil cool. Signs of underwatering include wilting leaves and stunted growth, while overwatering can lead to root rot.

You can expect your first celery harvest from mid June through early 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 long.

To harvest individual stalks, simply snap them off near the base of the plant. For a continuous harvest, focus on the outer stalks, allowing the inner stalks to continue growing. As our first frost approaches in early November, harvest any remaining celery before it gets damaged by the cold.

Here are the top 3 problems you might encounter growing celery in the Desert Southwest:

Bolting from Temperature Stress

• What it looks like: The celery plant prematurely sends up a flower stalk, making the stalks bitter and inedible.
• What causes it: Temperature fluctuations, especially heat stress, trigger bolting. This is common in our region's unpredictable spring and fall weather.
• How to fix/prevent it: Choose bolt-resistant varieties. Provide shade during periods of extreme heat. Consistent watering helps to reduce stress on the plants.

Hollow Stalks

• What it looks like: The celery stalks develop hollow centers.
• What causes it: Inconsistent watering and nutrient deficiencies. Celery needs a steady supply of moisture and nutrients to develop properly.
• How to fix/prevent it: Water deeply and regularly. Amend the soil with compost before planting. Fertilize with a balanced fertilizer every few weeks.

Stringy Stalks from Heat

• What it looks like: The celery stalks become tough and stringy, with a less desirable texture.
• What causes it: High temperatures during the growing season. Extreme heat can cause the celery to mature too quickly, resulting in stringy stalks.
• How to fix/prevent it: Plant in a location that receives some afternoon shade. Provide consistent watering. Harvest the celery before it gets too hot.

Desert Southwest Specific Challenges: Our extreme heat, arid humidity, and monsoon rainfall create a unique set of challenges for growing celery. Consistent watering is crucial to prevent bolting, hollow stalks, and stringy stalks. Shade cloth is essential for summer survival.

Companion planting can give your celery a boost in our Desert Southwest gardens. Green beans are great companions because they fix nitrogen in the soil, which celery loves. Cabbage benefits celery by attracting beneficial insects that prey on celery pests. Tomato plants provide shade, protecting celery from sunscald. Onions deter many common pests that bother celery.

Avoid planting carrots near celery. Carrots and celery compete for the same nutrients in the soil, which can stunt the growth of both plants.