Sweet peas evoke old-fashioned cottage gardens, with their fluttering blossoms and intense fragrance. Growing sweet pea vines is simple and exciting. Here are some tips to help:
Sweet peas are usually best directly sown into the garden. To assist germination, seeds should be nicked or soaked in water for several hours, to soften the seed coating. Seed can be sown outdoors from March to early June in a sunny, well drained site.
Once seedlings are about 5-10cm high pinch the tips to encourage strong side shoots. Sweet pea vines have tendrils and will attach themselves to most any type of support with meshing or lines. Regular deadheading or cutting for display will keep them blooming longer.
Sweet peas require regular watering, especially as the temperature increases. They prefer a somewhat rich soil and can be fed monthly with a fertiliser high in potassium, as used for tomatoes. Adding a bit of blood meal to the soil is thought to help keep the stems long and suitable for cutting. There are few pests or problems associated with sweet peas.
In New Zealand it is possible to have Sweet Pea flowers over a long period by growing types that are suited to flowering during winter, spring and summer respectively. Look for Dr Keith Hammett Solstice varieties that will flower in shorter daylight hours and mix these with the regular summer flowering varieties. Also try planting some in late Autumn and some in early Spring.