Snow Peas in Zone 7B — Pacific Northwest

Snow peas are a fantastic addition to any Pacific Northwest garden. The crisp, sweet pods are delicious raw, stir-fried, or lightly steamed, and they're incredibly rewarding to grow. Plus, the cool nights we often get in the summer here actually enhance their flavor.

While our wet springs and the potential for late blight can present challenges, the long growing season—nearly 200 days—gives you plenty of time to get a succession of snow pea crops in. You'll be harvesting fresh peas from late spring well into the fall.

If you're starting your snow peas indoors, aim to transplant them outdoors mid-March through mid-April. This gives them a head start while avoiding the wettest part of spring. Remember to harden off your seedlings for about a week before transplanting, gradually exposing them to the outdoor elements.

Space transplants about 3-4 inches apart along a trellis or support. Keep an eye on the weather forecast around transplant time; a late cold snap or heavy rain can stress young plants.

Direct sowing is the preferred method for snow peas, and it's easy! You can sow seeds directly into the garden from early March through mid August, giving you multiple harvests. Soil temperatures should be at least 45°F, so waiting a bit after the last frost is wise.

Prepare your soil by loosening it and adding compost. Sow seeds about 1 inch deep and 3-4 inches apart. Keep the soil consistently moist until germination, which usually takes about a week or two, depending on soil temperature.

Snow peas need consistent moisture, especially during flowering and pod development. Our dry summer months mean you'll need to pay close attention to watering, even though our mild summers rarely see temperatures above 90°F. The key is consistent moisture, not soggy soil.

Check the soil moisture about 2 inches deep – if it feels dry to the touch, it's time to water. Aim for about 1 inch of water per week, adjusting based on rainfall. Water at the base of the plants to avoid wetting the foliage, which can encourage powdery mildew in our dry-summer climate.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to yellowing leaves and root rot. A layer of mulch, like straw or wood chips, can help retain moisture and regulate soil temperature during our fluctuating spring and summer weather.

Snow peas are vining plants and need support to thrive. A simple trellis made of netting, string, or even repurposed branches works well. Their vines are lighter than snap peas, so you don't need anything too heavy-duty.

Install the support at planting time to encourage the plants to climb from the start. Gently guide the tendrils onto the trellis as they grow, and they'll quickly latch on. This keeps the pods off the ground, improving air circulation and reducing the risk of disease.

You can expect your first snow pea harvest from late April through early November, about 55 days after planting. The exact timing depends on when you sowed your seeds and the weather conditions. Look for pods that are flat, with just a hint of the pea outlines visible inside. The pods should be translucent and crisp, not bulging with peas.

Harvest by gently snapping the pods off the vine. Regular harvesting encourages continued production. As the first frost approaches in late October, harvest any remaining pods, even if they're not quite fully mature. They'll still be delicious!

Here are a few common problems you might encounter with snow peas in the Pacific Northwest:

• Powdery Mildew
• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die. Reduces plant vigor.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it (unlike most fungi).
• 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 surprisingly effective. Plant resistant varieties.
• Pea Aphids
• What it looks like: Clusters of small, soft-bodied green insects on stems and leaves, causing distorted growth and sticky honeydew.
• What causes it: Aphids thrive in mild weather and can multiply quickly. They are attracted to stressed plants.
• How to fix/prevent it: Knock aphids off plants with a strong stream of water. Introduce beneficial insects like ladybugs and lacewings. Insecticidal soap can be effective for heavy infestations.
• 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 drained soil create conditions for fungal pathogens to thrive.
• How to fix/prevent it: Improve soil drainage by adding compost and avoiding overwatering. Plant in raised beds if necessary. Ensure good air circulation around plants.
• 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.

Pacific Northwest Specific Challenges: Our mild, dry summers can actually create ideal conditions for powdery mildew, so be vigilant about air circulation and avoid overhead watering. Slugs can also be a problem, especially in the wet spring, so use your preferred slug control methods. Late blight is less of a concern for snow peas than for tomatoes and potatoes, but it's still wise to practice good garden hygiene and choose resistant varieties when available.

Companion planting can help your snow peas thrive. Carrots and radishes loosen the soil, which aids root development. Cucumbers and corn provide natural trellises and shade, which can be beneficial during warmer spells. Lettuce benefits from the nitrogen snow peas fix in the soil.

Avoid planting snow peas near onions and garlic, as they can inhibit pea growth. These alliums can release compounds into the soil that hinder the development of legumes.