Peas are highly versatile legumes that can be eaten in the pod or shelled. Even the shoots are included in recipes as a vegetable. Garden peas (Pisum sativum) were first cultivated throughout south-east Asia, China and Japan. Peas prefer to grow in cooler temperatures and, with the help of a greenhouse, make an excellent winter garden project. Greenhouses offer a more stable environment for pea plants and help protect against pests like insects and weeds. There are some steps to prepare the soil for successful pea cultivation.
Provide a silt, clay and sand loam for pea plants. The root systems of pea plants are susceptible to root rot and damage from soil compaction. Silt, clay and sand loams offer protection against compaction and provide nutrients for the plants.
Test the soil acidity. Peas prefer more alkaline soils in the range of 6.0 to 7.0. Lime can be supplemented when the soil becomes too acidic.
Use compost or manure to fertilise the soil. Thoroughly mix the compost 15 cm (6 inches) down into the soil. If fresh manure fertiliser is used, do not harvest any part of the pea plant for 90 to 120 days to ensure safety.
Take a soil sample to test for nutrients. Pea plants need adequate amounts of nitrogen, manganese, sulphur, phosphorous and potassium. Depending on the soil test result, nutrient supplements may need to be added to the soil.
Expose the seeds to Rhizobium leguminosarum before planting. Rhizobium is a bacterium of the soil that is naturally occurring and lives symbiotically with legume roots. Rhizobium is not always present in the soil, so it must be exposed to the pea seeds to grow with them and aid in the nitrogen fixing process.
Plant pea seeds in the greenhouse during late September. Peas prefer to grow in cool weather and a greenhouse helps to protect them from the harsh winter cold.
Space the seeds 2.5 to 5 cm (1 to 2 inches) apart. This helps to prevent root rot and allows the pea plants more room as they grow.
Water the pea plants. Allow the soil to drain between watering and do not let water to pool on the surface of the soil. This indicates that the soil is heavy and does not drain well.
Supplement sunlight with greenhouse lighting. Pea plants will need supplementary lights during the dark winter months.
Trim the tips of the pea plants when the shoots have reached 20 cm (8 inches). This prevents the pea plant from getting lanky and encourages stems to sprout.
Preparing the soil is an important step for preventing root rot, a common disease in pea plants, and other pathogens from infecting the plants.