Our garden pea, Pisum sativum, belongs to a genus of five species; it is found in the countries bordering the Mediterranean Sea and western Asia. The name 'Pisum' was used by the Roman poet Virgil, and up to 30 different varieties may have been grown by the Romans. Peas were, however, being grown as far back as 4500BC in Egypt.
In Tudor times peas were a delicacy, often imported from the Netherlands, making them expensive. Eating fresh peas became much more popular in the late 18th century, when British breeders started developing sweeter tasting varieties. Gregor Mendel used pea plants in his experiments relating to genetics.
Make a flat bottomed drill 15cm/6in wide and water it well. Sow about ten seeds per 30cm/12in, spacing them evenly in a zigzag manner. Cover with about 2cm/1in of soil, and firm it down with the flat edge of a rake. Allow about 60cm/12in between rows. As seedlings emerge, the shoots are very attractive to birds, but a few little twigs placed over the row will give some protection.
Autumn and early spring sowings will benefit from cloche protection. As the peas start to grow, support them with netting or pea sticks. Keep the plants well-watered, especially in dry spells.
Peas do best in an open position, but not one that is too exposed. They are naturally a cold weather crop, growing best in spring and cool summers. They do not thrive in hot weather, drought or poorly drained soils. Ideally the soil should be fertile, with the addition of well-rotted organic matter being particularly beneficial. Peas do not germinate well in cold soil, and this leaves them subject to attack by mice and fungal diseases. Do not sow too early in a cold spring.