Sun Requirements for Sweet Peas

Sunlight Requirements

• Sweet peas grow up to 10 feet in height. They require full sunlight on the heads and partial shade on the lower half of each plant. Full sunlight is characterized as six to eight hours of sun a day, meaning the tops of sweet peas need at least six hours of sun for healthy growth. The rest of the plant must receive four to six hours of sun or partial shade.

How to Plant

• For sweet peas to receive the correct amount of sunlight for the entire plant, their lower regions must be shaded by another plant. Gardeners may landscape their garden beds in a fashion where tall plants such as squash or beans shade the sweet peas. In addition, sweet peas need a structure to support their growth. A trellis or netting works well with this climbing vine. When landscaping, space the plants six to eight inches apart to give them enough room for air circulation.

Problems

• Gardeners experience problems when their sweet pea plants don't receive enough sunlight. Plants grown in full shade suffer from diseases and pests. Find out how much sunlight your yard receives by spending the day monitoring the sunlight. Draw a diagram of your yard. Indicate on the diagram the areas that receive six to eight hours of sun a day. To increase sunlight, prune back any overhanging tree branches.

Other Factors

• Summertime presents problems for sweet peas. Sweet peas prefer cool weather; intense heat or too much sunlight burns the plants. To help sweet peas weather the heat, spread a 3- to 4-inch layer of mulch around the plant. Sow sweet pea seeds in the ground when soil temperatures reach 55 to 65 degrees Fahrenheit. These ornamental plants are usually among the first plants sown after the last frost of the season.