Celery in Zone 7B — Desert Southwest

Growing celery in our Desert Southwest gardens might seem like a challenge, but the crisp, refreshing taste of homegrown celery is worth the effort. It adds a unique flavor to soups, salads, and snacks that you just can't get from store-bought stalks. Plus, the sense of accomplishment when you pull a perfect stalk from your garden is unbeatable.

Sure, our extreme heat and dry air present unique hurdles for celery. But with our long 245-day growing season and careful timing, you can absolutely enjoy a successful celery harvest. Starting early and paying close attention to watering will be your keys to success.

Starting celery indoors is essential in our region. You'll want to sow your seeds indoors from late December through mid January, about 10 weeks before you plan to transplant. Celery seeds are tiny and need light to germinate, so don't bury them too deeply—just press them gently onto the surface of your seed-starting mix.

Use seed trays with a good seed-starting mix, and keep them consistently moist. Bottom watering is a great way to prevent damping-off. Aim for a warm spot, around 70-75°F, and provide supplemental light if needed. Remember our spring here is very early, so stay on schedule.

Transplant your celery seedlings outdoors from mid March through mid April. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the intense desert sun and temperature fluctuations.

When transplanting, space the seedlings about 8-10 inches apart in well-prepared soil. Choose a spot that gets full sun to partial shade, especially during the hottest part of the day. Keep an eye on the weather; even in March and April, we can still get some surprising temperature dips.

Watering is absolutely critical for celery in our Desert Southwest climate. Celery is extremely thirsty and needs consistently wet soil. Even a brief dry spell can lead to hollow, bitter stalks. This is probably the most water-demanding vegetable you can grow here.

During the spring, aim to water deeply at least 2-3 times per week, providing about 1-2 inches of water each time. Once the extreme heat of summer hits, you'll likely need to water every day, or even twice a day. Use the finger test: stick your finger about 2 inches into the soil; if it feels dry, it's time to water. Focus on watering at the base of the plant to minimize water loss from evaporation in our arid climate.

Signs of underwatering include wilting leaves and stunted growth. Overwatering, while less common in our dry climate, can lead to root rot, so ensure your soil has good drainage. A layer of mulch around the plants can help retain moisture and keep the soil cooler.

You can expect your first celery harvest from early June through late July. Celery is ready to harvest when the outer stalks are at least 8 inches long. You can harvest individual stalks as needed, cutting them off at the base of the plant.

Alternatively, you can harvest the entire plant when the stalks are about 12 inches or longer. Simply cut the whole plant off at the base. For milder stalks, try blanching them by mounding soil around the base of the plant a week or two before harvesting. As our first frost approaches around mid- November, harvest any remaining celery, as it won't tolerate freezing temperatures.

Celery can face a few challenges in our Desert Southwest gardens: bolting from temperature stress, hollow stalks, and stringy stalks from heat.

Bolting from temperature stress

• What it looks like: The plant prematurely sends up a flower stalk, making the stalks bitter and inedible.
• What causes it: Fluctuations in temperature, especially early in the season, can trigger bolting. Our Desert Southwest springs can have unexpected temperature swings.
• How to fix/prevent it: Choose bolt-resistant varieties. Provide consistent watering and protection from extreme temperature changes with shade cloth.

Hollow stalks

• What it looks like: The stalks develop a hollow center.
• What causes it: Inconsistent watering and nutrient deficiencies, particularly calcium. Our alkaline soil can sometimes lock up nutrients.
• How to fix/prevent it: Maintain consistent soil moisture and amend the soil with compost. Consider a calcium supplement if needed.

Stringy stalks from heat

• What it looks like: The stalks become tough and stringy.
• What causes it: Extreme heat and lack of consistent moisture during the growing season. Our summers are known for extreme heat.
• How to fix/prevent it: Provide afternoon shade with shade cloth. Ensure consistent and deep watering, especially during the hottest months.

Desert Southwest Specific Challenges Our extreme heat, arid humidity, and occasional monsoon rainfall create a unique environment for growing celery. The key is to start early, provide consistent moisture, and protect your plants from the harshest elements. Don't be afraid to experiment with different varieties and techniques to find what works best in your garden.

Companion planting can be helpful for celery in the Desert Southwest. Green beans are good companions because they fix nitrogen in the soil, which benefits celery's growth. Cabbage repels some pests that might bother celery. Tomatoes provide some shade, which can help protect celery from sunscald. Onions deter celery flies. Avoid planting carrots near celery, as they compete for the same nutrients in our already challenging soil.