Sabrina Hahn's Expert Guide to Cultivating Sweet Peas in Your Home Garden
Sweet peas, scientifically known as Lathyrus odoratus, are widely regarded as the most admired and romantic annuals you can introduce to any garden. Their enchanting fragrance and soft pastel colours evoke nostalgic memories for gardeners and florists alike, making them a beloved choice for many.
Why Grow Sweet Peas from Seed?
Sabrina Hahn strongly encourages growing sweet peas from seed rather than seedlings. This approach offers a much broader selection of colours and sizes, and for seed savers, sweet peas typically remain true to form, ensuring consistent quality and characteristics in future plantings.
Optimal Growing Conditions and Planting Tips
Native to the Mediterranean region, sweet peas are usually climbers, though dwarf varieties are available. They require a full sun position and a support structure such as a trellis, frame, wooden stakes, bamboo poles, jute netting, an old gate, or wire mesh for climbing.
Traditionally planted on St Patrick's Day, with changing climates, it's advisable to wait until April in Western Australia to avoid the heat. Some varieties will flower in spring and autumn, providing seasonal beauty.
Soil and Fertilisation Requirements
Sweet peas thrive in free-draining, alkaline soil with a pH around 7, making them perfect for coastal gardens without the need for lime. In heavier, acidic soils, apply compost and hydrated lime to adjust conditions. As heavy feeders, they germinate better when sown directly in the ground. Use a granulated fertiliser with good potassium and trace minerals but low nitrogen once plants reach 10cm high.
Seed Treatment and Germination
Professional seed growers debate pretreating seeds; some recommend presoaking, while others deem it unnecessary, depending on seed coat hardness. Sabrina Hahn soaks seeds for a few hours in the morning before planting them that afternoon. Plant seeds 1-2cm deep, with germination occurring in 10-12 days. Protect seedlings from slugs, snails, and slaters by placing a small cup around them.
Where to Buy Sweet Pea Seeds
Online suppliers offering a good selection of sweet pea varieties that deliver to WA include Diggers, Tesselaar, The Seed Collection, and Veggie & Flower Garden Seeds. Local nurseries also typically stock sweet pea seeds, providing convenient access for gardeners.
Weekly Gardening Tip and Additional Tasks
Tip of the week: Install your support trellis before planting seeds, as you'll need to tie climbers as they grow. Picking flowers daily encourages more production and allows you to enjoy their gorgeous perfume indoors.
Three jobs to do now:
- Give rose bushes an autumn trim—a light prune before the hard winter prune—then fertilise and water.
- Combat citrus leaf miner by picking off affected leaves and binning them to interrupt the moth's life cycle.
- Purchase certified virus-free seed potatoes and plant them at the beginning of April.
For those with gardening questions, submissions can be sent to Ask Sabrina at GPO Box D162, Perth 6001 or via email to home@wanews.com.au, including full name and suburb. Note that due to volume, not all questions will be answered.
