Best Trellises and Plant Supports

The best trellises and plant supports are the ones that suit how each plant climbs and grows, so the right material, height and fixing keep climbers, roses and tall flowers upright for many seasons.

A flimsy trellis collapses in the first storm, and a support that’s too short leaves a plant sprawling. This guide explains the main types of trellises and plant supports, how to match them to climbers and tall flowers, and how to fix them safely. It’s general advice, and your local extension service or the Royal Horticultural Society (RHS) can add tips for your area. Links on this site may earn a commission, and that never changes what we recommend.

It belongs to the Flower Gardening guides and works with How to Grow Roses, How to Grow Dahlias and Low Maintenance Flower Borders.

Best trellises and plant supports at a glance

These are typical values. Wind, plant weight and soil change what you need, so choose stronger supports in an exposed garden.

How to choose trellises and plant supports

1. Check how the plant climbs. Sweet pea and honeysuckle twine, clematis wraps leaf stalks, and roses lean and need ties.
2. Find the full height. Choose a support at least as tall as the plant, and add 30 cm if the plant is vigorous.
3. Pick the material. Treated softwood is cheap, hardwood and galvanised or powder coated steel last longer, and bamboo suits annual crops.
4. Plan the fixing. Screw a wall trellis to battens 3 to 5 cm off the surface, and set freestanding posts at least 60 cm into the ground.
5. Allow for weight. Wisteria and mature roses are heavy, so use thick posts and strong wires.
6. Add soft ties. Use stretchy or twine ties and check them each season.

How supports, plants and wind affect each other

Twining plants such as sweet pea and honeysuckle climb thin canes and wire, while clematis grips narrow slats and mesh. Climbing roses lean on a support and need ties to carry the weight, and heavy wisteria pulls down a weak trellis. Dahlias and delphiniums grow tall flower spikes that snap in wind, so a stake or a cage prevents the damage. Peony and other floppy perennials flop under rain, and a grow-through grid holds the stems up while the leaves hide it.

A solid fence panel acts like a sail in wind, whereas an open trellis lets air through and puts less strain on the posts. A gap of 3 to 5 cm behind a wall trellis allows air to circulate and reduces powdery mildew on roses and clematis. Rot attacks softwood in wet soil, so set posts in metal sockets or treat the ends. Galvanised steel resists rust for 15 years or more, and powder coating protects it from scratches.

A worked example: a rose and clematis on a fence

For a fence panel 1.8 m tall and 1.8 m wide, screw battens 4 cm thick to the fence and fix a trellis to them. Plant a climbing rose 45 cm from the base, and train its main stems out sideways along the trellis at about 45 degrees to encourage flowers. Plant a clematis 60 cm away, and let it scramble through the rose with its roots shaded by low shrubs. Tie the rose with soft twine every 30 cm, and check the ties in spring and autumn. In a windy site, use 75 by 75 mm posts set 60 cm deep instead of relying on the fence alone.

Choosing supports for tall flowers and vegetables

• Dahlias: a stake of 1.2 m beside each plant, tied at three heights as it grows.
• Delphiniums and lupins: stout canes of 1.5 m, tied loosely with twine.
• Peonies: a grow-through hoop of 60 cm set early in spring so the stems grow up through it.
• Sweet peas and runner beans: a wigwam or obelisk of 1.8 to 2 m with canes 25 cm apart.
• Tomatoes: a stake or spiral of 1.5 m, or a cage for bush types.

Maintaining trellises and plant supports through the year

Check posts and ties each spring and autumn. Retie roses every 30 cm as new stems grow, and cut any tie that has started to bite. Treat softwood with a plant-safe preservative every 2 years, and brush rust from steel before you repaint it. Clematis and honeysuckle prefer cool roots, so mulch with 5 cm of compost and shade the base with a low shrub such as lavender. Compost feeds the climber and improves clay, and mulch protects roots and reduces weeds.

In winter, lower the stems of tender climbers away from a wet wall, and prune clematis according to its group, which your extension service or the RHS explains. Remove old canes after the season, because dead stems shelter slug and fungal spores, and dry them under cover for next year. Push a dahlia stake 30 cm into the soil before you plant, so you never spear the tuber.

Which support for which plant

Choosing materials for your climate

Timber suits a traditional border, but untreated softwood rots in 5 to 8 years in wet soil, whereas pressure treated or cedar lasts longer. Powder coated steel is strong and slim, and it holds heavy climbers such as wisteria without bending. Bamboo is cheap and light, and it suits annual climbers that last one season. Plastic coated wire resists rust, and it keeps a low profile on a small wall.

Heat from a south wall can scorch tender shoots on bare metal, so a wooden or coated support is kinder there. Check ties twice a year, and loosen any that cut into stems as they thicken. Soft garden twine or stretch tie protects stems better than thin wire.

Suggested picks to check

We have not tested these products ourselves. They are suggestions that match the criteria above, so check the current size, specification and price on the seller’s page before you buy.

Related guides

Read this guide with How to Grow Roses How to Grow Tomatoes How to Grow Dahlias The Cutting Garden Flowers That Attract Pollinators Best Gardening Tools for Beginners.

Common mistakes

• Buying a short support. A plant that outgrows it falls over.
• Fixing a trellis flat to a wall. Without a gap, air can’t pass and mildew builds.
• Shallow posts. Wind pulls them over, so set them at least 60 cm deep.
• Tying too tight. Ties cut into stems as they thicken.
• Forgetting to stake early. Adding a support after the plant has flopped damages stems.

Next steps

Check how each plant climbs, then choose a support that’s taller and stronger than you think you need. For roses read How to Grow Roses, for tall tubers read How to Grow Dahlias and for easy borders read Low Maintenance Flower Borders. The Flower Gardening guides link every step.