Colour your world
Their gorgeous fragrance and blooms make sweet peas a favourite
IT’S time to plant sweet peas. In Australia, St Patrick’s Day is the traditional day for sowing sweet pea seeds. But really, any time in March or April is okay. This timing allows the seeds to sprout and grow strongly through winter.
Once spring arrives, they are ready to flower. If you plant them too late they don’t have time to grow to flowering stage before the heat of summer.
The sweet pea (Lathyrus odoratus) is an annual, a member of the Leguminosae family. There are climbers and dwarf forms, and the flower colours vary from white and cream through pinks and crimsons to blues and purples. They bloom prolifically, and make a lovely cut flower. Many varieties have a delightful fragrance, too. All of the varieties that we grow today have been bred from the same parent seeds, which were sent by a Sicilian monk, Franciscus Cupani, to colleagues in Amsterdam and England in 1699. Seeds of this beautifully scented purple-maroon bicolour form, called Cupani, are still widely available.
The climbing forms of sweet peas can grow up to two metres, so they need some support. If you don’t have a fence or trellis, build a teepee by tying three or more tall straight sticks or stakes together at the top with some string. Have the support structure in place before you plant, as you may damage the roots if you poke stakes into the ground once your plants are growing. There are also dwarf varieties that don’t need support, but still produce large flowers on long, sturdy stems.
Sweet peas are easy to grow from seed. They prefer a sunny position, with plenty of organic matter and a sprinkling of lime or Dolomite in the soil. If you’re growing them in a pot, use premium potting mix. Some gardeners like to soak the seeds in water overnight, or scarify the seeds with something like an emery board to speed up germination. Sow seeds directly where they are to grow, about 2–4cm deep. Pea seeds won’t germinate readily in waterlogged soil, so plant into moist soil and then don’t water them again until the shoots emerge. Once the shoots are about 5–8cm tall, pinch out the tops to encourage side shoots, which will produce more flowers.
Flowering should begin about 12–14 weeks after planting. It’s important to keep picking the flowers and removing any seed pods to encourage more blooms to form.
Because sweet peas are a member of the legume family, they can create nitrogen and “fix’’ it in the soil. This means that, when the sweet peas are finished, you can chop the plants up and return them to the soil, and plant some nitrogen lovers such as leafy greens in that position.
Sweet peas should be sown in March or April for beautiful blooms in spring. SWEET PEA IS NATIVE TO SICILY, SOUTHERN ITALY AND THE AEGEAN ISLANDS IN EUROPE