Snow Peas in Zone 7B — Desert Southwest

Snow Peas are a fantastic addition to any Desert Southwest garden. The sweet, crisp pods are delicious raw, stir-fried, or added to salads. Plus, getting a harvest in both spring and fall is incredibly rewarding in our climate.

While the extreme heat of summer can be a challenge, the long growing season (around 245 days) and mild winters give you two opportunities to enjoy this cool-season crop. With careful timing and a little extra care, you can successfully grow Snow Peas here.

If you're starting Snow Peas indoors, aim to transplant them outdoors from mid February through mid March. Before planting, gradually acclimate your seedlings to the outdoor conditions by hardening them off for about a week. This involves exposing them to increasing amounts of sunlight and wind each day.

Space your transplants 3-4 inches apart. Keep an eye on the weather forecast and be prepared to cover your young plants if a late cold snap threatens. Our temperature swings can be dramatic.

Direct sowing is the preferred method for Snow Peas. Here in the Desert Southwest, you can sow seeds directly into the garden from early February through early September. The key is to avoid the peak heat of summer.

Prepare your soil by loosening it and adding compost. Snow Peas prefer well-draining soil with a pH of around 6.0 to 7.0. Sow seeds 1 inch deep and 3-4 inches apart. Keep the soil consistently moist until germination.

Consistent moisture is crucial for Snow Peas, especially during flowering and pod development. In our arid Desert Southwest climate, this can be a challenge. During the spring and fall growing seasons, aim to water deeply about 1-2 times per week, providing around 1 inch of water each time.

Use the "finger test" to gauge soil moisture. Stick your finger about 2 inches into the soil near the base of the plant. If it feels dry, it's time to water. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases, especially during monsoon season.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to yellowing leaves and root rot. A layer of organic mulch, like straw or shredded leaves, can help retain moisture in the soil and regulate soil temperature.

Snow Peas are vining plants and need support to grow properly. A simple string trellis, netting, or even branches stuck into the ground will work well. The vines aren't as heavy as snap peas, so you don't need anything too elaborate.

Install your support system at planting time to avoid disturbing the roots later. As the plants grow, gently train the vines to climb the trellis, ensuring they have something to grab onto. This will help keep the pods off the ground and improve air circulation.

You can expect your first harvest of Snow Peas starting in late March and continuing through late November. The exact timing will depend on when you planted your seeds. The pods are ready to harvest when they are flat, crisp, and you can just barely see the outlines of the peas inside.

Harvest regularly by snapping off the pods at the stem. This encourages the plant to continue producing more pods. As the first frost approaches in mid- November, harvest all remaining pods, even if they are a little small. They're still delicious!

Here are some common problems you might encounter with Snow Peas in the Desert Southwest:

• Powdery Mildew
• What it looks like: White or grayish powdery coating on leaves, stems. Leaves curl, yellow, and die.
• What causes it: Fungi thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it. Our monsoon season can create the perfect conditions.
• How to fix/prevent it: Improve air circulation through spacing and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays help. Milk spray (1 part milk to 9 parts water) is effective. Plant resistant varieties.
• Pea Aphids
• What it looks like: Small, soft-bodied insects clustered on stems and leaves. Stunted growth and distorted leaves.
• What causes it: Aphids thrive in mild weather. They suck sap from plants, weakening them.
• How to fix/prevent it: Blast aphids off plants with a strong stream of water. Introduce beneficial insects like ladybugs. Insecticidal soap can be effective.
• Root Rot
• What it looks like: Yellowing leaves, stunted growth, and wilting, even with adequate watering. Roots are brown and mushy.
• What causes it: Overwatering and poorly draining soil. Fungi thrive in wet conditions, especially in our heavy alkaline soils if not amended well.
• How to fix/prevent it: Improve soil drainage by adding compost and other organic matter. Avoid overwatering. Plant in raised beds if necessary.
• Fusarium Wilt
• What it looks like: Wilting on one side of the plant first, then spreading. Yellow leaves starting on one side. Brown streaks in stem when cut open.
• What causes it: Soil-borne fungus (Fusarium oxysporum). Persists in soil for years. Enters through roots. Warm soil temperatures favor it.
• How to fix/prevent it: No cure once infected — remove and destroy the plant. Plant resistant varieties (look for 'F' on seed labels). Rotate crops on a 4-year cycle. Solarize soil in hot zones. Raise soil pH above 6.5.

Desert Southwest Specific Challenges: The extreme heat of our summers can stress Snow Peas, making them more susceptible to pests and diseases. Low humidity can also be a factor, as can our alkaline soil. Pay close attention to watering needs and soil health to give your plants the best chance of success.

Companion planting can help Snow Peas thrive in the Desert Southwest. Carrots and radishes loosen the soil, making it easier for Snow Peas to establish their roots. Cucumbers provide shade, which is especially beneficial during our hot spring and fall days. Corn acts as a natural trellis, providing support for the vining plants. Lettuce helps suppress weeds and keeps the soil cool.

Avoid planting Snow Peas near onions and garlic, as these can inhibit their growth. Onions and garlic are allelopathic, meaning they release chemicals that can harm other plants.