The garden peas, Lathyrus species, are among the first crops harvested from the garden in a new season. Grow them for their tender pods or plump immature seeds, the "peas", or choose sweet peas for their dainty fragrant flowers, for bouquets. Grown as annuals, completing their life cycles in one growing season, garden peas like fertile soil and cool weather. Thus, they can grow in winter in the tropics or in midsummer in the high mountains.
The pea or bean family, Fabaceae, is gigantic in number of plants worldwide. Botanists further break down this plant family into subfamilies. Garden peas are in the subfamily Papilionoideae, grouping them with more close relatives, like beans. These legume crops are rich in protein. According to "Tropical Flowering Plants," by Kirsten Albrecht Llamas, members of this subfamily share a common-looking flower with one upper petal, two lateral, "wing" petals and two lower petals fused together into a "keel." The subfamily name literally means "butterfly-like", referring to these flowers.
Garden peas are informally grouped into shelling peas or edible-pod peas. Shelling peas develop tough-skinned pods and the tender peas inside must be shelled before making dinner. Edible-pod peas are tasty and tender throughout and are easily eaten whole. Edible-pod peas are also called sugar peas or snow peas. All garden peas, with origins in Europe centuries ago, naturally grow upright, as a thin, twining vine. These types exist today, as well as genetically selected "bush" types that remain shorter and require less maintenance in small gardens.
Grow peas in any fertile soil that is moist and well-draining, when temperatures remain below 80 degrees Fahrenheit, according to the Utah State University Extension Service. They tolerate light frosts, down to about 25 to 27 F, but prosper in the range of 60 to 65 F. Soak seeds overnight before directly sowing them into the soil where they are to grow. Depending on climate, you can raise garden peas in fall, winter or spring, planted in full sun to light shade. Tall, twining types need stakes or trellises to grow upon. Bush types don't need staking, but they do create long stems that grow into a small trellis matrix no taller than your knees. This makes pea pod harvesting a little easier.
Pea plants need little fertilizer, or none at all if you started with a fertile garden soil plot. When planting rows, space 2-feet between rows in planting bush types and 5-feet between tall, staking twining plants. If you must water plants, water only on the soil as overhead water that wets the foliage leads to disease problems. Once pea pods reach a harvestable size, about 2 to 3 inches long, pluck them gently from the brittle-stemmed plants. Pods that ripen cause the plant to stop flowering or producing more pods. Use the peas as soon as possible and refrigerate them unwashed for short term storage, as recommended by "Sunset Western Garden Book."
Watch out for slugs and snails as they will devour young pea plant seedlings. Overly wet soils and wet stems and foliage leads to many crop-reducing fungal problems such as powdery mildew, leaf spot, gray mold. The first signs of fusarium wilt and root-rot disease are the yellowing and wilting of the lower leaves and stunting of the plants. These diseases are not as prevalent on well-drained soils. Double-dug raised beds amended with abundant organic matter can greatly improve soil aeration and drainage according to the University of Illinois Cooperative Extension Service. Fusarium wilt can be avoided by growing wilt-resistant pea varieties.