February garden: sowing annual climbers

Summer may seem a distant memory but by sowing annual climbers now you'll feel like the next one isn't far away and, by the time it arrives, your garden will be bursting with blooms and busy with bees...

As with bedding, there's a range of easy-to-grow, climbing annuals that will flower non-stop from June until the frosts, producing striking blooms and sculptured leaves. Because they grow 1.8m to 3m or more in a season, half the joy is amassing so much plant from one small, inexpensive seed. Sweet peas aside, you rarely see annual climbers in borders, but their scarcity doesn't mean they're hard to grow with the right tools - ideally, a heated propagator in a greenhouse, but a frost-free porch or indoor windowsill will do.

Annual climbers are often grown as fast cover-ups for sunny fences and trellises, but they make willing pot plants for large containers, meaning you can still enjoy them if your borders are straining at the seams. They're well worth the trouble - their long-flowering nature beats clematis and climbing roses hands down and they give you a chance to get creative. To support them, we bought willow structures from an expert weaver but there are many suppliers of withies for weaving your own. Get cracking on this exciting project now and by summer you'll have a flower tower to be proud of.

Annual climbers to try

Asarina antirrhiniflora – A climbing snapdragon for sun or part-shade. Height 1.8m.

Cobaea scandens f. alba – A classy, ivory-white flowered climber. Height 3-6m in sun.

Dolichos lablab – An unusual climber with violet flowers followed by edible pods. Height 2.7m in sun.

Eccremocarpus scaber – An exotic-looking climber with crimson tubular flowers and fern-like foliage. Height 3m in sun.

Ipomoea tricolor – 'Heavenly Blue' The classic morning glory with flowers the colour of a summer sky. Height 3m in sun.

Lathyrus odoratus – 'Painted Lady' A very fragrant, old-fashioned sweet pea. Height 1.8m in sun. Rhodochiton atrosanguineus Fuchsia-purple lanterns, good for small pots. Height 1.8 2.4m in sun. Thunbergia alata Aka Black-eyed Susan, a cottage garden favourite with tangerine flowers. Height 1.8-2.4m in sun. Tropaeolum speciosum A fast climbing variety with exotic flowers. Height 2.4m in sun or part-shade.

Get the sowing right

• 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 to aid germination.
• Scatter the seeds on the surface, then cover with another thin layer of compost. All you need is a few plastic pots, labels, seed-sowing compost and the right heat and light conditions to start off seeds. To sow from late February use a heated propagator in a greenhouse, or place the seed tray in a warm, sunny spot inside. Alternatively, wait until the weather warms up in April and sow pots in a cold frame for slightly later-flowering plants.
• 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.
• 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.
• In April, harden off plants in readiness for moving outdoors by opening the greenhouse on warm days and, in May, placing them outside during the day. Pot on larger or fast growers and water with a balanced liquid feed if leaves start to yellow.