Thursday, December 26, 2019

How to grow Sturt’s Desert Pea

Here are some tips for growing Sturt's Desert Pea, Swainsonia formosa (formerly known as Clianthus formosus)

  • They are usually grown as annual plants but can live up to a few years if conditions are favorable.
  • The seeds have a long viability and can germinate after many years.
  • Wait until spring to plant your seeds, they prefer warm weather.
  • Sturt’s Desert Peas like a hot sunny location but can tolerate light frost.
  • They never survive if you transplant them, so plant the seed exactly where you want it to grow. If that first root is disturbed, the plant will die.
  • The plants send out runners that spread along the ground, so give them enough space to grow.
  • They prefer a loose, well-draining, inorganic soil similar to the soil used for cacti and succulents.
  • If growing in pots, use a pot that’s wide rather than deep, at least 6 inches deep but 12 or more inches across. Hanging baskets also work well.
  • Boil a cup full of water, let the water cool off until you can just barely put your finger in it without burning, then soak the pea seeds overnight or at least five hours.
  • Seeds that float don’t have an embryo, so don't use them.
  • After the warm water soaking, the seeds will germinate within a few days, and some may even appear within a day.
  • Protect from slugs, snails, and other pests.
  • When the plant is about 4 inches high you can begin regular applications of slow release fertilizer. Despite being desert plants they are heavy feeders and will reward you with lots of flowers if fertilized well. They are not phosphorus sensitive like some Australian native plants and do not need specialized fertilizer.
  • Sturt’s Desert Peas don’t like too much water, so don’t overwater them. Bottom watering may help to prevent rotting at the base of the stem. Mounding the soil, planting under eaves, unglazed terracotta pots, and hanging baskets may help them survive in rainy areas.
  • To keep plants compact and flowering well, pinch out the tips to encourage compact growth. Do not allow runners to become longer than 3ft. Cut back old stems after flowering, this will encourage new growth from the center of the plant.
  • A few seeds will germinate much later than the rest, so you might find new plants appearing weeks or months after sowing the seeds.
  • If you succeed it will be worth it. The flowers are large and numerous, and the color is intensely red. They are one of the most spectacular flowers in the pea family.
  • Sturt’s Desert Pea makes a great cut flower. If flowers are picked just as they open, they can last up to 30 days in water.
  • In the wild in Central Australia the flowers are pollinated by birds. However, even without pollinators and other plants around, you might find some seed pods are formed, giving you seeds for future planting. Allow the pods to dry completely before harvesting.

1 comment:

  1. I keep reading that you cannot transplant Sturts peas as they will not survive. Although a newcomer to growing the pea I have found it easy to transplant the pea at an early stage. A few weeks after germination and so long as the tap root is not broken I have 100% survival. I have also successfully transplanted 4 inch seedlings so long as the taproot is again not broken