Do Peas Need to Be Protected From Frost?

Very Hardy Category

• Pea plants are widely considered to be very hardy and capable of withstanding exposure to freezing temperatures and hard frosts. The caveat is, they can only tolerate this exposure for a short duration without suffering permanent injury. Seeds planted in the ground and the mature tissues of well established plants will generally be less susceptible to cold injury than tender young shoots, but even these will survive brief exposure of a few hours. Repeated exposure to near freezing temperatures, of less than 45-degrees Fahrenheit, over a short period or exposure over a prolonged period, calls for providing protection to give the pea plants. Any exposure to temperatures nearing 32-degrees Fahrenheit or lower will demand protection or the plants will be damaged irreparably.

Planting to Avoid Freezing

• Planting your pea plants in later spring, when they will be less likely to encounter freezing temperatures in your region is a good check against damage and can relieve some of the need for protection measures. The University of Illinois recommends planting your peas in the spring only after the soil temperature remains consistently above 45-degrees Fahrenheit and the soil is dried out enough that it no longer sticks to your garden tools as you cultivate. This often translates into four to six weeks before the frost free date for your area. The trick is to not wait too long to plant, as earlier plantings tend to produce more abundant harvests later in the spring.

When Protection Is Helpful

• When low temperatures and or frosts persist for a day or more, pea plants will benefit from some insulating protection. Without any protection there can be blackened frost damage to the plants, loss of tissue or the plant tops can be killed outright. If temperatures are expected to drop below 45-degrees Fahrenheit, row covers should be deployed to insulate the plants from cold and wind. Buy fabric row covers designed for crops that are light permeable and cover the peas without crowding the plants together and restricting air flow. The covers should be tall and wide enough so that they do not come into total contact with the pea plant. An alternative to row covers is plastic mulch sheeting laid over the soil around the plants that can trap heat in the soil during the day and release it at night to mitigate against the cold temperatures and stave off damage.

Protecting Peas Started Indoors

• Young pea plants that have been germinated and established indoors, before being transplanted outdoors, will be more vulnerable to cold injury simply because they have built up no tolerance to it. Even heavy frosts will stress the plants. These plants should be hardened off gradually by incremental exposure to lower ambient temperatures and higher sunlight levels over a period of two weeks. Cold frames and row covers should be employed to protect them. Alternatively, the plants can also be set on a cart or wagon and rolled outdoors during the day before being rolled back inside at night.