Peas are a classic sign of the spring garden, thriving in cooler temperatures. As a cool-weather crop, peas tolerate light frost, making them one of the first vegetables Wisconsin gardeners can plant. Successfully growing a pea harvest depends on timing the planting precisely to avoid the damaging effects of late spring heat.
Determining the Ideal Planting Window
The best time to plant peas is defined by soil condition: “as soon as the ground can be worked” in the spring. This means the soil is no longer saturated and can be crumbled easily. While peas germinate in soil temperatures as low as 40°F, the target for quick emergence is 45°F to 50°F.
Planting dates vary across Wisconsin’s climate zones. Southern gardeners typically begin sowing seeds around April 15th. Those in northern Wisconsin should wait until May 1st to ensure the soil has warmed sufficiently.
The goal is to complete the harvest before daytime temperatures consistently exceed 80°F to 85°F, which often happens by early June. Heat stress causes plants to stop producing flowers and makes the pods tough. To extend the fresh harvest, succession planting involves sowing small batches of seeds every two weeks until mid-May.
Selecting Pea Varieties for the Wisconsin Climate
Choosing fast-maturing varieties is important to ensure the crop finishes before the summer heat begins. Pea varieties are categorized primarily into shelling, snap, and snow peas.
Shelling peas, or English peas, require removal from the pod before eating; ‘Little Marvel’ and the wilt-resistant ‘Progress No. 9’ are good regional choices. Snap peas, such as ‘Sugar Snap,’ are eaten pod and all when the peas inside are plump. Snow peas, like ‘Oregon Sugar Pod II,’ are harvested flat and tender before the peas develop fully. Selecting varieties resistant to common diseases like Fusarium wilt is recommended for Wisconsin’s damp spring conditions.
Soil Preparation and Planting Techniques
Peas require a well-drained site, as saturated soil can lead to seed rot and root disease in the cold spring. Sandy loam soils that warm quickly are preferred, and incorporating compost or aged manure improves drainage. Peas thrive in a soil pH between 6.0 and 7.5.
Seeds should be planted about 1 inch deep and spaced 1 to 2 inches apart. For vining varieties, install a support structure, such as a trellis or wire fencing, immediately upon planting. This allows the young plants to climb as soon as they emerge.
A key step for maximizing yield is seed inoculation with Rhizobia bacteria just before planting. This introduces beneficial microorganisms that allow the plant to fix atmospheric nitrogen directly into the soil. Nitrogen fixation enhances plant vigor and fertilizes the soil for subsequent crops.
Ongoing Care and Harvesting
Once seeds germinate, consistent moisture is necessary, but avoid overwatering. The soil should be kept evenly moist, particularly when plants begin to flower and set pods. Excessive moisture near maturity can cause pods to split.
Weeding should be done carefully to avoid disturbing the shallow root systems. Mulching helps suppress weeds, keeps roots cool, and conserves moisture. Early-season pests, such as aphids, should be monitored and managed promptly.
Harvesting time depends on the type of pea, but all benefit from being picked at peak tenderness. Shelling peas are ready when the pods are full and plump, but the seeds remain soft. Snap peas should be harvested when fully rounded and juicy, while snow peas are picked when the pods are flat and tender. Regular picking encourages the plant to produce more pods.