When to plant peas in Friday Harbor and the San Juans, WA

A crop built for cool weather

Peas sprout in soil as cool as 40°F, though they come up much faster as it warms toward 60°F, and they grow best when days are 60 to 70°F. Seedlings tolerate light frost. Production drops once temperatures regularly top about 80°F, which is why peas go in early, from February to April depending on where you live.

The biggest early risk isn't cold but wet. Seeds sitting in cold, waterlogged soil rot, so plant into soil that crumbles in your hand rather than forming a muddy ball.

Nitrogen from the air

Like beans, peas host rhizobia bacteria in root nodules that turn nitrogen from the air into fertilizer for the plant. They need little added nitrogen, and an inoculant helps in beds that haven't grown peas recently.

A common belief is that peas leave lots of nitrogen in the soil. In fact, most of it ends up in the seeds you harvest. Cutting the vines and leaving the roots in the ground adds organic matter, but only a modest amount of nitrogen.

Soil and water

Peas like well-drained soil with a pH of about 6.0 to 7.5. Keep the soil moist once flowering starts, since dry spells during bloom and pod fill cut yields. A trellis gives better airflow and easier picking, even for shorter varieties.

Diseases

Powdery mildew shows up as peas wind down in summer heat. Pea enation mosaic virus, spread by aphids, causes stunted, deformed plants and is a particular problem for later plantings in the Northwest. Early planting and resistant varieties like Oregon Sugar Pod II help with both.

Why fresh peas taste sweeter

Pea sugars start converting to starch as soon as the pods are picked, and the conversion is fastest when they're warm. That's why homegrown peas taste so much sweeter than store-bought ones. Pick in the cool morning, refrigerate right away, and eat or blanch and freeze them within a day or two.

Pick snap and snow peas when pods are plump but crisp, and shelling peas when the peas fill the pod but the pod is still bright green. Frequent picking keeps plants producing.