Snow Peas in Zone 7A — Pacific Northwest

Snow Peas are a fantastic addition to any Pacific Northwest garden. Their sweet, edible pods are delicious raw in salads, stir-fried, or simply enjoyed straight from the vine. Plus, they thrive in our mild summers and cool nights, offering a satisfying harvest when other plants are still getting started.

While we might struggle with heat-loving plants sometimes, Snow Peas are perfectly suited to our climate. Our 183-day growing season gives you plenty of time to plant multiple crops. Just be mindful of the wet springs and potential for late blight, and you'll be rewarded with a bountiful harvest.

You can transplant Snow Peas outdoors in late March through mid April, giving them a head start on the season. Be sure to harden them off first by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the cooler temperatures and stronger sunlight.

When transplanting, space the seedlings about 3-4 inches apart. Keep an eye on the weather forecast – we sometimes get unexpected cold snaps in the spring, so be prepared to cover your seedlings if frost threatens.

Direct sowing is the preferred method for Snow Peas, and it's easy to do. You can sow seeds directly into the garden from early March through mid August. For the best results, wait until the soil has warmed up a bit, ideally to around 50°F.

Before sowing, amend your soil with compost to improve drainage and fertility. Plant the seeds about 1 inch deep and 3-4 inches apart. Keep the soil consistently moist until the seedlings emerge, which usually takes about a week or two.

Snow Peas need consistent moisture, especially during flowering, but overwatering can be a problem in our wet springs. During the spring, let rainfall do most of the work. You'll likely only need to supplement with watering during extended dry spells.

The "finger test" is a good way to check: stick your finger into the soil about 2 inches deep. If it feels dry, it's time to water. Aim for about 1 inch of water per week, either from rain or irrigation. Water at the base of the plants rather than overhead to help prevent fungal diseases in our sometimes humid conditions.

During our dry summer months, you'll need to water more frequently, perhaps every other day, depending on the weather. Underwatering will cause the plants to wilt and the pods to be small and tough. Overwatering, on the other hand, can lead to root rot, especially in heavy clay soils. Mulching around the plants with straw or wood chips can help retain moisture and keep the soil cool.

Snow Peas are vining plants and need support to grow properly. A simple trellis made of string, netting, or wire mesh works perfectly well. Since Snow Peas have lighter vines than snap peas, you don't need anything too heavy-duty.

Install the trellis at planting time so the seedlings can start climbing right away. As the plants grow, gently guide the vines towards the trellis and encourage them to wrap around the supports. This will keep the plants off the ground, improve air circulation, and make harvesting easier.

You can expect your first harvest of Snow Peas from early May through late October, about 55 days after planting. The best time to harvest is when the pods are flat, and you can just barely see the pea outlines inside. The pods should be translucent, crisp, and tender.

To harvest, gently snap the pods off the vine, being careful not to damage the plant. Regular harvesting encourages continued production, so check your plants every few days. As the first frost approaches in mid- October, harvest all remaining pods, even if they're a bit smaller than usual.

Here are some 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). This can be an issue during our dry-summer months when we still get cool nights.
• 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 insects (usually green) on stems and undersides of leaves. Stunted growth, curled or yellowing leaves, sticky honeydew.
• What causes it: Aphids are attracted to stressed plants. Overcrowding and poor air circulation can exacerbate the problem. They thrive in mild weather, making spring and fall peak seasons in the PNW.
• How to fix/prevent it: Blast aphids off plants with a strong stream of water. Introduce beneficial insects like ladybugs and lacewings. Insecticidal soap can be effective. Avoid over-fertilizing with nitrogen, which attracts aphids.

Root Rot

• What it looks like: Yellowing leaves, stunted growth, wilting (even with adequate water), mushy brown roots.
• What causes it: Overwatering and poorly drained soil create an environment where fungal pathogens thrive. Our wet springs can make this a challenge.
• 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. Use a fungicide if the problem is severe.

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: Late blight, while more common on tomatoes and potatoes, can occasionally affect peas. Ensure good air circulation and avoid overhead watering to minimize risk. Cool soil in spring can slow germination, so consider warming the soil with plastic before planting. Slugs can be a nuisance, especially for young seedlings, so use slug bait or traps as needed.

Good companions for Snow Peas include carrots, radishes, cucumbers, corn, and lettuce. Carrots and radishes help break up the soil, making it easier for pea roots to penetrate. Cucumbers and corn provide natural trellises for the peas to climb. Lettuce benefits from the shade provided by the pea vines during our mild summers.

Avoid planting Snow Peas near onions and garlic, as these can inhibit pea growth. Onions and garlic are allelopathic, meaning they release chemicals into the soil that can be harmful to other plants.