Mar, Apr, May
To encourage germination, soak the seeds overnight in cold water to soften their coating. Keep the different varieties separate and clearly labelled.
Use 10cm pots and fill with a seed-sowing compost. Scatter the seeds on the surface, then cover with another thin layer of compost.
Keep pots covered in a propagator at approximately 21-24°C (average room temperature). Water regularly to prevent the compost drying out but don't let the pots become waterlogged.
Easy to grow, climbing annuals will flower non-stop from June until the frosts, producing striking bloom.
Seedlings should appear within two to three weeks. Once the first true leaves appear, transfer each seedling to its own pot, holding it by the leaf not the stem. Keep watered and in a frost-free place.
Once climbers start to grow, give the pots some more room and push twiggy supports into the compost to prevent plants tangling with each other. From April, gradually harden off plants in readiness for moving outdoors.