Sabrina Hahn: How to grow sweet peas at home including planting tips and where to buy sweet pea seeds

Sweet peas are without a doubt the most admired and romantic annuals you can plant in a garden. They evoke nostalgic memories for many gardeners and florists alike, thanks to their enchanting fragrance and soft pastel colours. Every time I bring a bunch of sweet peas inside it takes me back to my childhood filled with memories of my grandmother’s and mother’s gardens, who grew sweet peas every year. My nan would always place a vase of sweet peas near my bed, saying the fragrance would give me sweet dreams and that they were the fairies’ favourite flowers. Sweet peas (Lathyrus odoratus) are not edible and belong to a different genus, but they are definitely worth growing. I encourage everyone to grow them from seed rather than using seedlings; there is a much broader selection of colours and sizes when you buy seeds. Additionally, for the seed savers out there, sweet peas typically remain true to form. Sweet peas are native to the Mediterranean region and are usually a climber, but dwarf varieties are available. They require full sun and a trellis or frame for climbing. You can use wooden stakes as teepees, bamboo poles, jute netting, an old gate, or wire mesh as a support structure. Sweet pea flowers are produced on racemes of between 2-8 beautifully fragrant flowers to 3.5cm-wide in colours from white through pink, lilac, blue, purple, magenta, burgundy and even bicoloured. Sweet peas were traditionally planted out on St Patrick’s Day but with a changing climate, it’s still too hot in WA to plant them out until April. Some varieties will flower in spring and autumn. Professional seed growers debate about whether to pretreat the seed before sowing. Some swear by presoaking the seed, others say it’s unnecessary. Basically, it will be determined by how hard the seed coat is. I have always soaked the seed in the morning for a few hours then planted them out that afternoon. Luckily, sweet peas prefer a more free-draining, alkaline soil around a pH of 7 — making them perfect for coastal gardens, and there’s no need to add lime. In heavier, more acidic soils, apply compost and hydrated lime. Sweet peas are heavy feeders and germinate better if sown directly in the ground. Use a granulated fertiliser that has good levels of potassium and trace minerals but low nitrogen once they reach 10cm high. Plant the seed 1-2cm deep. Germination occurs in 10-12 days. Unfortunately, slugs, snails and slaters love to eat the seedlings, so put a little cup around them for protection. Online suppliers of a good selection of sweet pea varieties that send seed into WA include Diggers, Tesselaar, The Seed Collection, and Veggie & Flower Garden Seeds. Your local nurseries will also have sweet pea seeds available. Tip of the week Have your support trellis in place before planting out the seeds because you will need to tie the climber up as it grows. The more flowers you pick, the more flowers it will produce. Pick daily, and bring the gorgeous perfume into the house. Three jobs to do now 1. Roses can have an autumn prune — this is a light prune before the hard winter prune. Fertilise and water after pruning. 2. Citrus leaf miner will still be active. Pick off affected leaves and bin to interrupt the life cycle of the moth. 3. Buy seed potatoes that are certified virus-free, and plant out at the beginning of April. Do you have a question for Sabrina? To submit a question to Green With Envy, inside Saturday’s The West Australian, write to Ask Sabrina, GPO Box D162, Perth 6001 or email home@wanews.com.au. Please include your full name and suburb. Due to the volume of questions, not all of them will be answered.