Best Climbing Plants to Grow from Seed: 10 Vines for Height & Colour

An annual climber does in four months what a woody climber takes four years to manage. Sow a packet in April, and by July you have three metres of leaf and flower over a fence that was bare at Easter — for less than the price of a coffee. It is the fastest, cheapest way to add height to a garden, which is why almost every gardener tries it and why so many are quietly disappointed. The plants grow beautifully and then flop, sag, or sulk halfway up. The reason is almost never the seed. It is that the plant was given the wrong thing to climb.

• Sow Mar–May indoors for most annual climbers
• Season's growth 2–4 m in a single summer
• Support Match it to how the plant climbs
• Container size 30–40 litres minimum per plant

The one thing that decides whether a climber works

Climbers are usually chosen by flower colour. They should be chosen by climbing mechanism, because that dictates the support — and a plant on the wrong support will spend the summer falling off it.

There are three groups worth knowing. Twiners wind their whole stem around something: morning glory, runner beans, pole beans, jade vine. They need a vertical they can actually get round — a cane, a rope, a wire, anything up to about 5 cm thick. Wrap a twiner around a 10 cm fence post and it simply slides down. Tendril climbers throw out thin grabbing threads: cobaea, passionflower, sweet peas, cucumbers. They need something thin and frequent — mesh, netting, pea sticks, horizontal wires 20 cm apart. A single smooth pole gives a tendril nothing to hold. Leaf-stalk climbers and scramblers hook themselves on with twisted leaf stems or simply lean: thunbergia, rhodochiton, nasturtiums. These need dense support, or a host plant, or tying in.

Nothing you grow from seed will self-cling to brick the way ivy does — that is a woody-plant trick. If the wall is bare, the support goes up first. Our guide to plant supports and trellising covers the construction side; this article covers what to put on it.

Ten climbers worth growing from seed

• Morning glory (Ipomoea) — the classic twiner, 3 m in a season, saucer flowers that open at dawn and are finished by teatime. Soak the seed 12–24 hours before sowing; it needs real warmth to start. The Ipomoea purpurea types are the most forgiving. Note the seed is toxic if eaten.
• Black-eyed Susan vine (Thunbergia alata) — the best climber for a big pot, 1.5–2 m of orange, cream and apricot from July to frost. Tolerates part shade better than almost any other annual climber. See the Thunbergia alata varieties.
• Cup-and-saucer vine (Cobaea scandens) — the giant of the group: 5 m of tendril-gripping growth and flowers that open cream and age to deep violet. Sow the big flat seed on its edge, not lying flat, or it rots before it germinates. Browse Cobaea scandens.
• Passionflower (Passiflora) — slower and more architectural, and perennial in a sheltered spot or conservatory. Germination is erratic and can take six weeks; sow more than you need. See the passion flower range.
• Climbing nasturtium (Tropaeolum) — the beginner's climber: big seed, sows direct, no fuss, and both leaves and flowers are edible. Poor soil gives more flowers than rich soil. More in the Tropaeolum collection.
• Runner beans — grown as an ornamental long before anyone ate them, and still one of the best scarlet screens you can make. A vigorous twiner that needs a proper wigwam.
• Pole and climbing French beans — the productive twiner: purple, yellow and green-podded types that look as good as they crop, on the same frame.
• Peas — tendril climbers, and the only one on this list you can still sow in some gardens for an autumn crop. Give them netting, never a bare pole.
• Cucumbers and small squash — vertical growing saves enormous ground space and keeps fruit clean; support heavy fruit in a sling.
• Jade vine (Strongylodon macrobotrys) — the ambitious one: a tropical perennial twiner with turquoise flowers, for a heated conservatory only. We cover it properly in our jade vine growing guide, and the seed sits in the Strongylodon collection.

Sweet peas deserve an honourable mention — tendril climbers, and the one group on this list that is genuinely better sown in October than in spring. You will find the whole vertical range in our climbing flowers collection.

How to grow climbers from seed, step by step

1. Put the support up first Before the plant goes in, not after. Retrofitting a frame around a two-metre vine breaks stems and tears roots. Match it to the mechanism: cane or rope for twiners, mesh for tendrils.
2. Sow warm, in deep pots Most annual climbers are half-hardy: March to May at 18–21 °C indoors. Use root trainers or 9 cm pots — climbers make long roots fast and hate being checked. See starting seed indoors.
3. Help the difficult seed Soak ipomoea 12–24 hours; set cobaea seed on edge; be patient with passiflora, which can take six weeks. Our guide to germinating seeds explains the why behind each trick.
4. Pinch at four true leaves Take out the growing tip and you get three or four leaders instead of one bare rope with leaves at the top. This one job transforms thunbergia, cobaea and ipomoea.
5. Plant out after the last frost Harden off over 10–14 days first — see hardening off. In the ground, allow 45–60 cm between plants; in pots, 30–40 litres each, minimum.
6. Guide the first metre by hand Wind twiners onto the support anticlockwise or clockwise as they naturally go, and tie in scramblers weekly. Once they are away, they look after themselves.

Annual or perennial climbers?

The pragmatic answer is to plant a perennial and sow an annual alongside it for the first two summers, so the frame is never bare while the slow plant catches up — the same logic as succession sowing applied vertically.

Common mistakes with climbers

• Wrong support for the mechanism — a twiner on a thick post or a tendril climber on a smooth pole will never hold. Match the two and most problems disappear.
• A pot that is too small — the commonest reason a climber stalls at a metre. Below 30 litres you are watering twice a day and it still sulks; see our container growing guide.
• Never pinching — one unpinched leader gives a bare stem with a tuft of flowers out of sight at the top.
• Underestimating wind — a climber in full leaf is a sail. Anchor obelisks properly; wind, not cold, wrecks most of them.
• Too much nitrogen — rich feeding gives spectacular foliage and almost no flowers. Switch to high-potash once buds form; our feeding guide has the detail.
• Letting them dry out at flowering — a stressed climber drops buds within days. Water deeply and less often, as our watering guide explains.

Frequently asked questions

What is the fastest-growing climber from seed?
Cup-and-saucer vine (Cobaea scandens) covers the most ground — 4 to 5 m from an April sowing. Morning glory and runner beans are close behind at around 3 m, and both are easier from seed. All three need their frame in place before planting.

Can I sow climbing plants in late summer?
Most annual climbers are half-hardy and want spring warmth, so late August is planning-and-ordering time rather than sowing time. The exceptions: sweet peas in October, peas for an autumn crop, and tender perennials like passiflora and jade vine, which can be started under glass at any point. Check what is in season in our September and October sowing collections, or the autumn sowing guide.

Which climbers grow in shade?
Genuinely few. Thunbergia alata and rhodochiton cope with three or four hours of sun; climbing nasturtiums flower reasonably in part shade; and for foliage rather than flower, a leafy bean will fill a shady frame. Everything else on this list wants six hours or more.

Do I need to save climber seed or buy fresh?
Beans, peas and nasturtiums come true and are easy to collect — see our seed saving guide. Named ipomoea and thunbergia varieties are often hybrids and will not come true, so buy those fresh each year.

Height is the thing most gardens are missing, and it is also the cheapest thing to add — a frame, a packet, and one summer. Browse the climbing flowers collection, the annual flower range or the edible flowers if you would like your vertical to earn its keep; underplant the base with something low from our pansy guide, dip into the rest of our growing guides, or check the sowing calendar and the August sowing list. Choose the support first — the plant will do the rest.