Climbing plants on the balcony: a living screen in pots, and frost

A timber screen goes up in an hour. A green wall takes a few weeks, and then it belongs to you again every year. On a balcony the trick is the same as in the garden, only tighter: the plant climbs, you supply the hold and the root room. Choose the pot too small and you do not lose the plant to thirst in July. You lose it to frost in January.

This piece is written for balcony and terrace containers. For a green wall in open ground, Green up your privacy screen is already there. Here it is about pot size, wind, load, and which climber actually survives the winter outdoors.

Three strategies, one railing

Before you shop, decide what the wall should do in January. That saves you the December disappointment of sitting in front of a bare frame.

Sun, shade, wind: read the balcony

A south balcony cooks the pot in July and gives you mild nights against the wall in winter. A north balcony stays cool and damp. Wind at the corner of a tower block rips shoots off and dries the compost as if a hairdryer were parked beside it.

For a sunny south or west balcony, clematis, hop, grapevine and climbing rose fit. The rose does not climb on its own, you tie it in. For partial shade take honeysuckle, alpine-type clematis, or a climbing hydrangea, which is slow and takes years. For a north balcony ivy remains the reliable choice, plus Virginia creeper, which glows in autumn and stands bare in winter.

Passionflower (Passiflora caerulea) flowers spectacularly and, in wine-growing climates with protection, can stay outside. In a pot on a harsh balcony you bring it into a cool stairwell before the first real frost. It is not a January screen.

Know the pruning group and you keep the flowers. ‘Jackmanii’ blooms on new wood and is cut back hard in late winter, CW 8 to 12. The three groups are in Pruning clematis.

The cultivar ‘Jackmanii’ is the classic for a pot: deep violet, vigorous, happy to be cut. Two plants side by side close a railing faster than one.

The pot is half the plant

On a balcony there is no garden soil storing heat at night. There is a bucket of compost, and in January it is as cold as the air once it has frozen through. So you do not buy the pot for the look of the bowl. You buy it for the litres.

A working rule:

• Annual climbers: 10 to 20 litres, with a support in the trough or on the rail.
• Clematis, ivy, honeysuckle: 30 to 40 litres, 40 is better.
• Hop, grapevine, climbing rose: 40 to 50 litres, more rather than less.

The larger the volume, the less often you water in summer and the slower the temperature in the ball falls. Plastic holds moisture, terracotta breathes and cools harder at night. For winter, a frost-proof plastic tub with a thick rim is often the more practical partner. Clay looks lovely and needs extra insulation.

Drainage holes are not negotiable. A layer of expanded clay or gravel at the bottom keeps the hole clear. Garden soil from a bed has no business in a pot: it packs, it stagnates, it rots. Use container compost with a share of garden compost, loosen it with a little bark humus, and mulch the surface so the sun does not bake the ball.

Which support fits which climbing type is in Climbing plants and supports. Short version: twiners (hop, honeysuckle) want poles and wires. Tendril climbers (clematis, vine) want thin mesh. Scramblers (climbing rose) you tie in. Self-clingers hold on alone, which is exactly why you keep them on the balcony frame, not on the house wall.

Hardy in the bed, vulnerable in the pot

Catalogues write “hardy to minus 20 degrees". That means roots in the ground, under leaves, under snow. In a pot the same ball sits like a finger in cold water. Minus eight degrees over three nights is enough to kill fine feeder roots. The plant shoots reluctantly in April, or not at all, and you think it froze. Often it was only the pot.

1. From CW 44, move it to the wall

   Stand the pots tight against a sheltered house wall, preferably east or south-east. The wall stores daytime heat and takes the edge off the wind.

2. Lift it off the stone

   Under the pot goes a wooden batten, a board or a foam sheet. Concrete and tiles pull the cold up into the ball from below.

3. Wrap the pot only

   Jute, coir or horticultural fleece around the tub, not as a tent over the whole plant. Evergreens need to breathe. Film without air holes sweats and rots.

4. Water on frost-free days

   Evergreens keep transpiring. A bone-dry ball in frost is fatal. Water sparingly when it thaws, and leave nothing standing in the saucer.

Mediterranean container plants (oleander, citrus, olive) are a different league. Those go into a cool quarters before frost, see Overwintering container plants. Climbers such as ivy, hop and viticella clematis stay outside.

Evergreen: the wall that survives January

If you do not want the neighbour looking at your plate in December either, you need leaves that stay. Two species do that reliably on a balcony.

Ivy (Hedera helix) clings with aerial roots. In a pot you train it on a trellis, not on the house wall. It takes shade, likes even moisture, and in harsh winters on sunny east winds it gets leaf scorch. That looks ugly and is rarely the end of the plant. New leaves arrive in April. Variegated cultivars are more tender than dark green foliage.

Evergreen honeysuckle (Lonicera henryi) winds around ropes and poles, scents lightly and keeps its leaf. It grows promptly; in a 30- to 40-litre pot it stays manageable. The berries are not for people, birds take them. Because the species romps, it belongs in the pot and not over the rail into the estate border.

Two plants in a 2-litre nursery pot are the start, not the destination. Pot them on into the large tub as soon as you have them, and give them the trellis on day one. Plant in autumn, CW 38 to 44, and the roots get six to eight weeks before the soil goes cold.

Scented honeysuckle (Lonicera caprifolium), the woodbine, drops its leaves in cold winters. The plant stays hardy, as a January screen it drops out. For a July evening balcony it is still one of the loveliest climbers you can set.

Virginia creeper (Parthenocissus quinquefolia) is a self-clinger with adhesive pads. On a balcony you lead it on a trellis, or it sticks to render and window frames. In October it is the finest wall for miles, in February a drawing made of sticks. Anyone who buys it as a winter screen buys the wrong plant. Anyone who loves autumn buys exactly this one. More on ivy and Virginia creeper as habitat is in the wildlife-garden piece.

The first year: annual climbers that need no patience

Perennials need a season before they close the railing. If you move in in May and want a screen in June, you sow annuals.

Runner beans after the Ice Saints, mid-May · CW 20, on strings or poles. They give a wall of leaves and a crop, with the method in Runner beans: support, cultivars and harvest. Sweet peas you start on the windowsill from CW 12 and plant out after the Ice Saints. Nasturtium sows itself into the trough on the rail, edible right into the flower. Morning glory wants heat and full sun, and from June it hangs its trumpets into the neighbouring flat, politely and densely.

In autumn you pull the annuals, compost the remains, and the pot is free for the next clematis. Or you leave the pot empty over winter and start again in April. Both are fine. What is not fine is selling an annual morning glory as “hardy". It is not.

Planting, watering, feeding

Set hardy climbers in autumn · CW 38 to 44 or in spring · CW 12 to 18. The ball is dunked before potting until the bubbles stop. The graft of a climbing rose stays above the compost. With clematis you may plant deeper, five to eight centimetres, so that if wilt hits it can reshoot from the buried stem.

Watering means the finger test. The top layer may dry, the ball beneath must not turn to dust. On hot days on a south balcony that is morning and evening. Empty the saucer after 20 minutes, or the root sits in warm water. Feed from April to July, organic and in measure. From August you drop nitrogen, so the wood can ripen and frost does less harm.

In Gartenkern you can set summer watering and the wrap from CW 44 as repeating tasks. A photo of the wall in June and one in January will tell you next year more honestly than any label whether you need evergreen, or can live with the bare frame.

Häufige Fragen

Which climbing plants work as a privacy screen on a balcony?

For winter, ivy and evergreen honeysuckle, both in a large pot with root protection. For summer, hop, clematis and Virginia creeper, which stand bare in winter and come back fast from May. For the first year, runner bean, sweet pea, nasturtium and morning glory, which go out after the Ice Saints and end with the frost.

How large does the pot need to be for climbing plants?

Perennial climbers need 30 to 50 litres of compost, hop and vine the upper half of that. Annuals manage with 10 to 20 litres. The larger the vessel, the slower it dries and the better the ball comes through frost. Drainage holes and a drainage layer are always required.

Which climbing plants are hardy in a pot?

Ivy, hop, viticella clematis, Virginia creeper, honeysuckle and climbing hydrangea are frost-hardy in a bed and stay outside on a balcony if you protect the pot: against the wall, off the stone, wrapped. Passionflower in a pot is only outdoor-hardy in mild sites, otherwise bring it in frost-free. Annuals are not hardy.

When do you plant climbers on a balcony?

Hardy perennials go in in autumn · CW 38 to 44 or in spring · CW 12 to 18. Annuals and frost-tender plants such as morning glory and passionflower wait for the Ice Saints, mid-May · CW 20. The trellis is in place before the plant goes into the pot.

Do I need a trellis on the balcony?

Yes, as soon as the plant does not cling by itself. Hop and honeysuckle wind around poles and wires, clematis and vine reach for thin mesh, climbing roses you tie in. Ivy and Virginia creeper cling alone, on a balcony still on their own trellis in the pot, not on the house wall or the neighbour's facade.

Does the screen stay in winter?

Only with evergreens: ivy and evergreen honeysuckle. Hop, clematis, Virginia creeper and grapevine stand without leaves from November to April. That is not damage, that is their rhythm. Anyone who wants year-round density pairs an evergreen with a summer-flowering climber in two pots.