Peas have been eaten since ancient times, and they are grown today as an essential member of the vegetable garden. The role peas play in restoring soil fertility and their preference for cool weather distinguishes them from many other vegetable plants. Cooks and gardeners alike recognize the versatility and importance of the pea.
Peas belong to the legume family of plants. While all plants require nitrogen to survive, legumes have a distinctive characteristic: They can convert, or "fix" nitrogen available in the atmosphere and convert it for use by plants. While nitrogen is the most prevalent element in our atmosphere, it is not in a form that plants can use. The root systems of legumes, however, provide a home for helpful bacteria that are able to take the nitrogen from the air and fix it into nitrogen the plant can use. Legumes and these bacteria, called rhizobia, each rely on each other in a mutually beneficial relationship. Legumes also help other plants when small amounts of the nitrogen produced in their roots become available for those plants as well.
Peas are one of the few common garden vegetables that will survive temperatures below freezing, so they are one of the first crops to appear at the farmer's market and one of the earliest harvests from kitchen gardens. In fact, most peas dislike weather over 70 degrees F and stop producing when the weather gets hot. Because of this, in the southern United States, it is not uncommon for gardeners to sow their peas in the fall so that they germinate right away in the spring and make the most of the cool spring weather before the summer heat arrives.
Friends and Enemies
Just like people, plants in the wild form communities where the different members help each other out. Similarly, some plant species don't grow well together. The art of companion planting seeks to combine plants in groupings that will help all of the members to thrive. Pea plants get along well with all early vegetables--radishes, lettuces and greens--but particularly benefit from living close to potatoes and cucumbers. They don't grow as well near garlic and onions.
Archeologists have unearthed peas in Egyptian tombs from the 12th dynasty, while Chinese legends credit Emperor Shu Nung with discovering peas 5,000 years ago. However, until the 17th century, peas were eaten dried in Europe due to a Roman misbelief that fresh peas were poisonous. Dried peas, however, proved useful to store for times of famine and long voyages. In Norse mythology, the god Thor sent dragons to fill all of the wells with peas as a punishment to the Scandinavian people. Some of the peas missed the wells and sprouted in the earth, leading the Norse to dedicate the pea to Thor and eat it only on his day, Thursday.