Celery in Zone 9B — Desert Southwest

Growing celery in the Desert Southwest might seem like a challenge, but the crisp, refreshing taste makes it worth the effort. Imagine fresh celery sticks with hummus, or a flavorful addition to your soups and stews – all from your own garden. Plus, the satisfaction of growing something a little different in our climate is pretty rewarding.

Sure, our extreme heat and arid conditions present unique hurdles, but with careful timing, celery can thrive here. Our long growing season, kicking off early and stretching late into the fall, gives you two chances to get it right. Let's get started!

You'll want to start your celery seeds indoors from mid November through mid December. That's about 10 weeks before you plan to transplant them outside. Use seed trays with a good seed-starting mix. Celery seeds are tiny and need light to germinate, so don't bury them too deeply – just press them gently onto the surface of the soil.

Keep the trays consistently moist by bottom watering. Place the tray in a shallow container of water and let the soil soak it up from the bottom. This prevents disturbing the delicate seeds. Place the trays in a warm location, around 70-75°F, and provide plenty of light. Remember, our spring warmth comes early, so this head start is crucial.

Transplant your celery seedlings outdoors from early February through early March. This avoids the worst of our winter frosts and gives them time to establish before the extreme heat arrives. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade, then slowly increase the time and sun exposure each day.

Space the seedlings 8-10 inches apart in a well-prepared bed. Our late winter weather can be unpredictable with temperature swings, so keep an eye on the forecast and be ready to cover the seedlings if a late frost threatens.

Celery is a water hog. Seriously, it's probably the thirstiest thing you can grow in your garden, so consistent watering is critical for summer survival. In our Desert Southwest climate, that means paying close attention. You're aiming for consistently wet, but not soggy, soil.

During the cooler months (February-April and October-November), aim for about 1-1.5 inches of water per week. Once the extreme heat hits (May-September), bump that up to 2-2.5 inches per week, or even more if the plants show signs of stress. Check the soil moisture regularly using the finger test – stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Water at the base of the plants to avoid wetting the foliage, which can lead to fungal problems in our arid climate.

Signs of underwatering include wilting leaves and bitter-tasting stalks. Overwatering can lead to root rot, so watch for yellowing leaves and a musty smell. A good layer of organic mulch, like compost, will help retain moisture in the soil and keep the roots cool.

You can expect your first celery harvest from early May through mid June, about 85 days after transplanting. Look for outer stalks that are at least 8 inches long and thick enough to eat. You can harvest individual stalks as needed, or cut the entire plant at the base when the stalks are 12+ inches tall.

To harvest individual stalks, simply snap them off near the base of the plant. Be careful not to disturb the remaining stalks. For a milder flavor, blanch the stalks by mounding soil around them a week or two before harvest. As the first frost approaches in mid- December, harvest any remaining celery, as it won't tolerate freezing temperatures.

Here are some common celery problems you might face in the Desert Southwest:

Bolting from temperature stress

• What it looks like: The plant sends up a flower stalk prematurely, and the stalks become bitter and tough.
• What causes it: Rapid temperature fluctuations, especially during the early stages of growth. In our region, this can happen during temperature swings in late winter or early spring.
• How to fix/prevent it: Choose bolt-resistant varieties. Provide consistent watering to reduce stress. Use shade cloth during the hottest parts of the day to protect plants from extreme heat.

Hollow stalks

• What it looks like: The inside of the celery stalks are hollow and lack crispness.
• What causes it: Inconsistent watering or nutrient deficiencies. Celery needs a steady supply of water and nutrients to develop properly.
• How to fix/prevent it: Ensure consistent watering, especially during hot weather. Fertilize regularly with a balanced fertilizer. Amend soil with compost before planting.

Stringy stalks from heat

• What it looks like: The stalks are tough, fibrous, and difficult to chew.
• What causes it: High temperatures and lack of moisture. The extreme heat of our summers can cause celery to become stringy.
• How to fix/prevent it: Provide shade during the hottest parts of the day. Ensure consistent watering. Choose heat-tolerant varieties.

Desert Southwest Specific Challenges: Our extreme heat, arid humidity, and occasional monsoon rainfall create a unique set of challenges for growing celery. The extreme heat can cause bolting and stringy stalks, while the low humidity increases the risk of underwatering. Monsoon rains, while welcome, can lead to fungal diseases if the plants are not properly ventilated. Consistent monitoring and proactive measures are essential for success.

Companion planting can give your celery a boost in the Desert Southwest. Green beans are a great choice because they fix nitrogen in the soil, which celery loves. Cabbage family plants also make good companions, as they can help deter pests. Tomatoes and onions are also beneficial, as they can help repel certain insects that might bother your celery. Avoid planting carrots near celery, as they compete for the same nutrients in the soil.