Snap Peas in Zone 7A — Pacific Northwest

Snap peas are a fantastic addition to any Pacific Northwest garden. Their sweet, crisp pods are delicious raw, stir-fried, or added to salads, and they thrive in our mild summers and cool nights, which enhance their flavor. Plus, there's nothing quite like the satisfaction of harvesting fresh peas from your own backyard.

While our wet springs and the risk of late blight can present challenges, snap peas are relatively easy to manage with proper timing and care. Our 183-day growing season gives you a long window to enjoy multiple harvests, especially with succession planting.

You can transplant snap peas outdoors from late March through mid April, giving them a head start. Before transplanting, be sure to harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the temperature swings and wind we often experience in the spring.

When transplanting, space the seedlings 3-4 inches apart. Keep an eye on the weather forecast and be prepared to cover them with row covers if a late frost is predicted – those overcast spring days can still bring a chill!

Direct sowing is the preferred and easiest method for growing snap peas here in the PNW. You can start sowing seeds directly into the garden from early March through early August. Like garden peas, snap peas prefer cool soil, so getting them in the ground early is key.

Prepare the soil by loosening it and adding compost. Ensure the soil temperature is at least 40°F (4°C) for best germination. Sow seeds about 1 inch deep and 3-4 inches apart. Keep the soil consistently moist until the seedlings emerge.

Snap peas need consistent moisture to produce plump, sweet pods. In our dry-summer climate, you'll need to pay attention to watering, especially during those drier stretches in July and August. While snap peas are more heat-tolerant than shell peas, they still need regular watering.

During the wet springs, you likely won't need to water much, if at all. But once the dry summer months arrive, check the soil moisture regularly. Stick your finger about 2 inches deep into the soil – if it feels dry, it's time to water. Aim for about 1 inch of water per week, either from rainfall or irrigation. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our sometimes humid conditions.

Signs of underwatering include wilting leaves and small, shriveled pods. Overwatering, on the other hand, can lead to yellowing leaves and root rot. A layer of mulch, like straw or wood chips, can help retain moisture and keep the soil cool during the mild summer heat.

Snap peas are vines and need support to climb. A trellis made of string, chicken wire, or even repurposed pea brush works well. Aim for a support system that's 4-6 feet tall, as some varieties can grow quite high.

Install the support at planting time to avoid disturbing the roots later. As the plants grow, gently guide the vines towards the trellis, and they will naturally start to climb.

You can expect your first harvest of snap peas starting in early May and continuing through late October, depending on when you planted. Snap peas are ready to harvest when the pods are plump, crisp, and the peas inside are fully developed, but still tender. The entire pod should be eaten.

Harvest regularly to encourage continued production. Use scissors or your fingers to gently snap off the pods, being careful not to damage the plant. As the first frost approaches in mid- October, harvest all remaining pods, even if they are not quite fully mature. You can still enjoy them, or add them to soups and stir-fries.

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

Powdery Mildew

• What it looks like: A white or grayish powdery coating on the leaves, stems, and sometimes pods. Leaves may curl, yellow, and die.
• What causes it: Fungi that thrive in warm days, cool nights, and moderate humidity – conditions we often see during our late summers. Dry leaf surfaces actually favor it.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning if needed. Remove affected leaves. Neem oil or potassium bicarbonate sprays can help. A milk spray (1 part milk to 9 parts water) is surprisingly effective. Plant resistant varieties.

Pea Aphids

• What it looks like: Small, soft-bodied insects clustered on stems and leaves, often causing distorted growth.
• What causes it: Aphids are attracted to stressed plants. Our wet springs followed by dry summers can sometimes create stress.
• 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 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 and mushy.
• What causes it: Fungi that thrive in overly wet soil. Our wet springs can create ideal conditions for root rot.
• How to fix/prevent it: Ensure good soil drainage. Avoid overwatering. Plant in raised beds if your soil is heavy clay. Improve soil with compost to increase drainage.

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). Persists in the soil for years. Enters through roots. Warm soil temperatures favor it.
• How to fix/prevent it: There is 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 heat and dry-summer rainfall can create conditions favorable for powdery mildew, so good air circulation and proper watering are key. Slugs can also be a problem, especially in the spring, so use slug bait or other control methods as needed. Late blight is less of a direct threat to snap peas than it is to tomatoes and potatoes, but it's still wise to practice good garden hygiene to minimize its spread.

Companion planting can help your snap peas thrive. Carrots and radishes are good companions because they help loosen the soil, making it easier for pea roots to grow. Cucumbers and corn provide natural trellises for the peas to climb on. Lettuce benefits from the shade provided by the pea plants, helping to prevent bolting in our mild summers.

Avoid planting snap peas near onions and garlic, as these can inhibit their growth.