What You Will Need
Top-quality sweet pea seed
- Potting soil
- 6-foot-tall fencing
- In warmer regions (Zone 7 and above) where winter weather is relatively mild, sweet peas can be sown in fall. Everywhere else, sow in late winter/early spring. Soak the seeds in water for 24 hours before sowing. This softens the seed coat and speeds up the sprouting process.
- While the seeds are soaking, fill your planting pots with good quality potting soil. Sweet peas produce abundant roots, so use the deepest pots you can find. Root trainers and 4-inch (10 cm) pots are ideal.
- Sow two seeds per pot, poking them a half-inch (1.25 cm) into the soil with your finger.
- Cover pots with a plastic dome lid to increase humidity and speed up germination. Place in a cool greenhouse or in a bright window in the house.
- Once plants are 4 to 6 inches (10 to 15 cm) tall, pinch out the central growing tip, just above a leaf joint, leaving just two or three leaf nodes. This will encourage the plant to branch vigorously from the base.
- Sweet peas are heavy feeders and require a little extra pampering to produce abundantly. Prepare planting beds by applying bone meal, a thick layer of compost or well-rotted manure, and a generous dose of natural fertilizer. Mix these ingredients deeply into the soil.
- Vines grow rapidly and require a strong structure to climb. Place tall posts roughly 8 feet (2.4 m) apart down the row and attach either Hortonova netting or 6-foot-tall (1.8 m) metal fencing for them to scramble up.
- Plant seedlings out around the last spring frost in two rows, one on each side of the trellis, roughly 8 inches (20 cm) apart down the row. As the vines explode into lush growth, it's important to keep them tied to their trellises. Once the vines get going, sweet peas can grow more than a foot (30.5 cm) a week.
- Sweet peas love water, and without consistent moisture they'll fail to thrive. Keeping their thirst quenched during warm weather is crucial, so set up soaker hoses as soon as you plant them to keep their lush growth unchecked. Feed plants weekly with diluted fish and seaweed emulsion.
- For the longest vase life, pick when there are at least two unopened flowers at the tip of a stem. Add flower food to the water to extend vase life. To prolong blooming, it's important that you keep plants from setting seed, so be sure to harvest and deadhead the flowers frequently.