University of Vermont Extension 
Department of Plant and Soil Science

Spring News Article

YEAR OF THE PEA

Dr. Leonard Perry, Extension Professor
University of Vermont

Each year the National Garden Bureau celebrates and promotes a particular vegetable and flower.  This year's vegetable is the pea, a vegetable which helps the soil, has an interesting history, and is a more versatile food than you might know.

The pea (Pisum sativum), is a member of the legume family, which in addition to meaning it has the pea-shaped flowers known so well, means that it also fixes nitrogen in the soil.  Peas have a symbiotic relationship with a bacterium that takes excess nitrogen from the soil.  This nitrogen is then stored in nodules on the pea roots, to be released as the roots decay. Think of it as an organic source of slow-release nitrogen.

In addition to storing nitrogen, the roots of pea plants help loosen the soil as they reach out for moisture.  Once the plants die, merely turn them back into the soil to replenish organic matter.

No one knows just when peas first became cultivated.  Perhaps it was as early as the Stone Age.  Peas were a part of the diet during the Bronze Age.  They have been found preserved in ancient tombs in the Mideast, dating back to 1450 BCE.  The Chinese believe in their legends that peas were cultivated 5000 years ago.

Peas were used extensively in the Middle Ages in Europe.  They were one of the first crops the colonists brought to the New World.  Our traditional pea is often called the English Pea, as it was in England that the garden pea we know today was so extensively bred.  You may remember the name Gregor Mendel, famous for his discoveries in genetics using the pea.

The most important recent advance in breeding peas occurred in 1970.  It was in that year that plant scientist Calvin Lamborn discovered what we know as the edible pod or snap pea.  'Sugar Snap' was introduced in 1979 and won a gold medal in the All-America Selections trials.

There are three types of peas one can find and grow, the differences depending on when they are harvested, and how they are eaten.  English or shelling peas are allowed to fully ripen in the pod.  These are the traditional ones most of us have opened, removing the peas from inside or "shelling," then cooked without the pod.

Snow peas are harvested before the peas inside are ripe, while they are still quite small.  The entire pod is then cooked and eaten.  You may have eaten these raw in salad bars or in stirfry dishes.

Snap peas can be eaten both ways.  They can be harvested like the snow peas, before the peas inside are mature, and eaten raw or cooked.  I love to eat them right off the vine.  Or, they may be allowed to mature, as with English peas, then shelled and eaten similarly. 

When choosing what peas to grow, don't just consider these three types.  Consider whether you want dwarf (1 to 2 feet tall), semi-dwarf (2 to 3 feet tall), or tall varieties (3 to 6 feet tall).  Also read the descriptions and choose varieties for early, mid, and late maturing.  This way you can ensure a much longer season of harvest.  Another method of doing this is to make a succession of sowings rather than all at once, each about two weeks apart.

Sow seeds directly outside about four to six weeks prior to the last frost date-- generally about mid to late April in USDA hardiness zone 4 (much of Vermont for instance). Sow seeds about 1 to 2 inches apart and deep.  Sprinkle an inoculant in the row when sowing (available at garden centers and from mail order sources) to help plants better fix nitrogen, so grow better.

Taller varieties will need a fence, trellis, or other creative means of support.  You may also need to surround pea seedlings with a low fence if you have rabbits foraging nearby!  Fertilize lightly, water well as you would the rest of your garden, and harvest the pods frequently when ready.

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