Peas and butter beans are considered companion plants and may be planted in the garden together. Peas, however, are a cool-weather crop whereas butter beans, also referred to as lima beans, are a warm-weather crop. Peas can withstand frost, while butter bean plants can be killed by even a light frost. Ideal planting times vary depending on the growing climate. Choosing pea and bean types that are suitable for your growing season and preparing the garden ahead of time will help to ensure a successful crop.
All types of peas are frost hardy and can survive temperatures well below freezing. Mature pea plants can survive temperatures down to -6.67 degrees Celsius. Young pea plants may survive temperatures down to -4.44 degrees Celsius, but will sustain damage. Generally, if pea plant seedlings are damaged by freezing temperatures, it is best to start over. Newly planted pea plants will grow more quickly and be more productive than freeze-damaged pea plants.
Do not plant butter beans until all danger of frost has passed and the soil temperature is higher than 10 degrees Celsius. They should be planted as soon as possible, however, especially in locations with short growing seasons. Most types of butter beans will take at least two months to produce beans and the bean pods will not set if temperatures stay consistently above 29.4 degrees Celsius. For best results in cooler locations, plant short-harvest bush types. Pole butter beans generally take three months to set a crop.
In USDA hardiness zones 8 and above, peas are commonly planted in the winter and harvested in the spring. Do not plant peas in the fall in hot climates. While the plants are not harmed by hard frost, the flowers are. Fall-planted peas will bloom right around hard frost time in these areas. Either bush or pole-type butter beans can be grown successfully in hot climates. The plants grow throughout the summer and produce beans in early fall when the temperatures cool. Once they begin producing beans, they will continue throughout the fall until the plants are killed off by frost. They may also be planted in August for a fall crop.
Prepare the garden well in advance of planting time so that you can plant the peas and beans as soon as conditions are right. For spring planting, prepare the garden in the fall. This is especially important for peas in cold winter climates, which should be planted as soon as the soil thaws. Both peas and butter beans grow best in organically rich fertile soil. Add well-aged manure or compost to the garden soil. Make sure it is mixed in completely and the soil is loose. Add sand to heavy clay to improve drainage. If you add commercial fertiliser to the soil, do not use high-nitrogen fertiliser. Peas and beans are legumes, which pull nitrogen from the air and add to the soil naturally. When a high-nitrogen fertiliser is used, the plants will grow vigorously with lush foliage but the bean and pea harvest will be reduced.