Snow Peas in Zone 6B — Pacific Northwest

Snow peas are a fantastic addition to any Pacific Northwest garden. Their sweet, edible pods are delicious raw in salads or lightly stir-fried. Plus, they’re incredibly rewarding to grow, offering a prolific harvest even with our mild summers and cool nights.

While we might face challenges like cool soil in spring and the occasional late blight scare, the timing for snow peas aligns perfectly with our 162-day growing season. By choosing the right planting window, you can enjoy a bumper crop.

You can transplant snow pea seedlings outdoors from early April through early May. This gives them a head start, especially if your spring soil is slow to warm up. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week.

Space transplants 3-4 inches apart in well-draining soil. Keep an eye on the weather; unexpected late frosts can happen in the PNW, so be prepared to cover your seedlings if temperatures dip.

Direct sowing is the preferred method for snow peas, mirroring how we plant garden peas here in the PNW. Sow seeds from mid-March through early August for a continuous harvest.

Prepare your soil by loosening it and amending with compost. Snow peas prefer soil temperatures above 45°F, so wait until the ground has warmed up a bit. Plant seeds 1 inch deep and 3-4 inches apart. Keep the soil consistently moist until germination.

Snow peas need consistent moisture, especially during flowering, but overwatering in our wet springs can be a problem. Aim for about 1 inch of water per week, but adjust based on rainfall; we often get plenty of rain in spring, but our dry summer months require more attention.

Stick your finger about 2 inches into the soil to check moisture levels. 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 in our humid springs.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to yellowing leaves and root rot. Mulching around your plants with straw or compost helps retain moisture and regulate soil temperature, a plus for our cool nights.

Snow peas are vining plants and need support to climb. A simple string trellis, netting, or even branches stuck in the ground work well. Their vines are lighter than those of snap peas, so you don't need anything too heavy-duty.

Install your chosen support at planting time so the seedlings can start climbing as soon as they emerge. Gently guide the tendrils towards the support as they grow to encourage them to latch on.

You can expect your first harvest of snow peas from mid-May through mid-October, about 55 days after planting. Look for pods that are flat, translucent, and crisp, with just barely visible pea outlines inside.

Gently snap the pods off the vine, being careful not to damage the plant. Regular harvesting encourages continued production.

As our first frost approaches in early October, harvest any remaining pods, even if they're a little small. They'll still be delicious!

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

Powdery Mildew

• What it looks like: A white or grayish powdery coating on leaves, stems, and sometimes pods. Leaves may curl, yellow, and die.
• What causes it: Various fungi thrive in our warm days, cool nights, and moderate humidity. Dry leaf surfaces favor it.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning. Remove affected leaves. Apply neem oil or potassium bicarbonate sprays. A milk spray (1 part milk to 9 parts water) can also be effective. Plant resistant varieties.

Pea Aphids

• What it looks like: Clusters of small, soft-bodied, green insects on stems and undersides of leaves. Leaves may be distorted, yellowed, or stunted.
• What causes it: Aphids thrive in mild weather and can quickly multiply.
• How to fix/prevent it: Blast aphids off plants with a strong stream of water. Introduce beneficial insects like ladybugs or lacewings. Insecticidal soap can also be effective.

Root Rot

• What it looks like: Yellowing leaves, stunted growth, and wilting, even when the soil is moist. Roots may be brown, mushy, and smell rotten.
• What causes it: Overwatering and poorly draining soil create conditions for fungal pathogens to thrive, especially in our wet springs.
• How to fix/prevent it: Improve soil drainage by amending with compost and avoiding overwatering. Ensure good air circulation around plants. Consider raised beds.

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 the stem when cut open.
• What causes it: A soil-borne fungus (Fusarium oxysporum) that persists in the 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. Raise soil pH above 6.5.

Pacific Northwest Specific Challenges: Late blight, while more common in tomatoes and potatoes, can occasionally affect peas. Maintaining good air circulation and avoiding overhead watering helps prevent its spread. Slugs can also be a nuisance, especially for young seedlings; use slug bait or traps to protect your plants.

Snow peas thrive alongside several companions in the Pacific Northwest garden. Carrots and radishes loosen the soil, benefiting the pea roots. Cucumbers provide shade during our mild summers, helping to keep the soil cool. Corn acts as a natural trellis for the peas to climb. Lettuce, being a low-growing crop, doesn't compete for sunlight and can even help suppress weeds around the pea plants.

Avoid planting snow peas near onions or garlic. These alliums inhibit the growth of peas.