Autumn Purple Sweet Pea

Sweet peas are delightful and very popular plants that combine delicate and very pretty flowers with a beautiful fragrance. St Patrick’s Day (March 17th) has been the traditional day to sow sweet peas, however, it’s often best to wait for cooler conditions in April to sow them. In the tropics and subtropics, sow sweet peas later still in May.

How to grow sweet peas in a garden

  1. Choose a well drained spot in the garden that has full sun and is sheltered from wind.
  2. Enrich the soil with some compost and Yates Dynamic Lifter Soil Improver & Plant Fertiliser before planting.
  3. Sow into damp soil where the sweet peas are to grow and lightly cover with soil. Tall growing varieties will need a support to climb up.
  4. If your soil is acidic (has a low pH) also apply some Yates Hydrangea Pinking Liquid Lime & Dolomite. This will help to raise the soil pH (make it more alkaline), which sweet peas prefer.
  5. Only water again sparingly until seedlings emerge in around 2 weeks time. Too moist soil can lead to the seeds rotting. As the tender new seedlings emerge, they’ll be vulnerable to snails and slugs. A light sprinkling of Blitzem Snail & Slug Pellets around the sweet pea patch will help protect the seedlings from snails and slugs.
  6. Once the seedlings are around 5 cm tall, start feeding each week with Yates Thrive Rose & Flowers Liquid Plant Food. This fast acting complete fertiliser provides nitrogen for healthy leaf growth, phosphorus for strong root development and potassium for lots of lovely sweet pea flowers.
  7. Tall varieties will need to be grown on a frame, trellis or tepee. Young seedlings may need to be supported with small twigs or bamboo skewers until they can reach their trellis.
  8. Sweet peas take around 12-14 weeks to flower. Don’t forget to cut handfuls of deliciously scented flowers for a vase.
  9. As the plants grow, watch for signs of powdery mildew, which appears like a dusting of talcum powder over the leaves. If not controlled, this disease will progress to causing the leaves to yellow, plant health will suffer, and the flower show cut short. Powdery mildew can be controlled with regular sprays of Yates Rose Gun. It comes in an easy to use trigger applicator and contains a systemic fungicide which moves around the plant’s system to control common diseases like powdery mildew.

How to grow sweet peas in a pot

  1. Choose a pot that has adequate drainage holes and place it in a position that gets full sun and is sheltered from wind.
  2. Fill the pot with Yates Potting Mix with Dynamic Lifter.
  3. Sow into damp potting mix where the sweet peas are to grow and lightly cover with potting mix. Tall growing varieties will need a support to climb up.
  4. Do not water for a couple of days after sowing. If the potting mix becomes dry water gently to keep it slightly moist while the seeds are germinating.
  5. Once the seedlings are established, feed every 1 to 2 weeks with Yates Thrive Roses and Flowers Liquid Plant Food. 
  6. Pinch out first buds to encourage bushier plants.
  7. Remove any spent flowers to prolong the display.

Growing tips

  • If sowing first in seed raising mix take extra care when transplanting as Sweet peas resent root disturbance. 
  • If heavy rainfalls are expected close to planting time, start the seeds off in toilet paper rolls filled with damp seed raising mix. Don’t be tempted to water the seeds for at least a couple of days after sowing and only apply small amounts of water to the seeds to keep the soil lightly moist. Once germinated, plant the toilet paper rolls containing the young plants directly where they are to grow and water in well.
  • Apply some mulch around the base of the plants to help retain soil moisture.
  • Sweet Peas are traditionally sown on St Patricks Day (17 March) however can be sown later in autumn in many areas around Australia.
  • For maximum sunlight exposure have the trellis running in a north-south direction.
  • You can create little Sweet Pea tepees in the backyard which is a delight for kids.
  • Pick blooms regularly to promote further flowering.
  • Once flowering has finished and the plant begins to wither, dig them directly into the soil as a green manure which adds nitrogen to the soil.
  • Do not consume the fruits or seeds of the Sweet Peas as they are poisonous if eaten.

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