Landscape designers Angela Choi and Alison Malouf of Flock Party Studio designed a medal-winning balcony garden at the RHS Chelsea Flower Show 2022.
And they also have balconies themselves. So they really know what works and what doesn’t. Here are their tips, plus additional inspiration from three other balcony gardens.
What’s the aspect? Sunny, windy, shaded? Don’t assume the conditions will be the same as on the ground
Find out what load the balcony can take. If there’s no information, keep weight to under 70kg per square metre.
Decide what you want to do on your balcony. A solitary haven or a place for friends? Wildlife friendly or an ‘extra room’ in your home?
Choose lightweight materials for pots, planters, arches and furniture. You can even get lightweight compost.
Place large or heavy pots or furniture close to the building’s walls as that is the strongest area.
Use vertical space for planting – arches, hanging baskets, vertical planting systems
Choose the right plants. Start with drought tolerant and wind tolerant plants, but experiment with what works on your own balcony micro-climate.
Use colour on walls, pots and planters for definition and atmosphere.
Plants in pots need feeding in summer and watering all year round.
You can even plant underneath your feet using a grid (see below!)
This balcony garden by Alison Malouf and Angela Choi of Flock Party design studio shows how you can literally grow plants on every area of your balcony from underfoot to overhead. It’s designed as a bird-friendly balcony. Birds can use the moss under the grid as nesting material.
How do you start a balcony garden?
When you start most gardens, you start with the aspect. Is it in full sun or very shady? How windy is the site? What is the soil like?
Of course, on a balcony garden, you don’t have to think about the soil, but it is important to assess how sunny or shady the balcony is and whether it is exceptionally windy.
Don’t assume that the conditions will be similar to those on the ground nearby. ‘Even if you live in a mild climate, being higher up can expose you to stronger winds,’ says Angela. Some plants that would do fine in gardens on the ground won’t cope with the extra winds higher up. ‘Some trees, for example, take well to that and will grow smaller in a natural bonsai effect. But others will just die.’
And there is another factor – the weight of your balcony garden. ‘It’s a good idea if you can get hold of the structural drawings for your balcony to check what weight per square metre the balcony can hold,’ says Angela. ‘You’d know what load it could take and where the structural supports are, so you can put your heaviest items there.
If there’s no information on this, try to keep things close to load bearing walls, where there is more support. Keep the weight of everything combined (including furniture and people) under 70 kg per square metre. This is the standard weight, and all the balcony gardens on RHS shows have to conform to this.
Flock Studio designers Angela Choi and Alison Malouf both have balcony gardens themselves, so they know what works and what doesn’t.
Decide what you’ll use your balcony for
Is your balcony garden a place to sit with a friend? Or do you want to grow food? Create an outdoor room? It’s important to decide this before you buy or design anything.
Angela and Alison were fascinated by the way that birds use the infrastructure of the urban environment as much as humans do. So they created their show garden balcony ‘for both birds and humans’, says Angela. It’s focused on the Eurasian Jay and was called Jay Day, but the principles would work for all birds.
Are you going to use your balcony for bird-watching? Me trying out some bird watching binoculars from Swarovksi Optik, who sponsored the Jay Day balcony garden at RHS Chelsea. It was really quite a revelation – I could see a sparrow on the top of a tall tree quite clearly from over 100 yards away. The grid behind me shows seat/table built into the balcony. It allows human beings to take a coffee outside and plants to grow under it for the rest of the time.
You could also use your balcony for growing edible plants, as the Cirrus Garden did, create it as a private space for meditation and reflection (the Blue Garden) or as a workspace (The Potting Garden.)
Choose the lightest weight materials possible
Use the lightest materials for pots, compost and furniture you can find, says Angela.
You can get a lightweight compost, such as Doff Lightweight Compost. Check its weight once water has been added, however, and take that into account when keeping to your weight per square foot. (although not all plants will enjoy that, so finding out which do and which don’t is part of developing your balcony garden style.) If you use ordinary compost, Angela says you can use less by adding a lightweight filler at the bottom of the pots.
Place large or heavy planters close to the building wall, because that is the part of the balcony with the most support.
Layer the space vertically and horizontally
Angela and Alison layered the balcony space by breaking it up with both horizontal and vertical grids and railings.
For example, the overhead canopy grid (see pic below) can hold climbing plants while the supporting vertical grid can be used either for hanging plants, bird feeders or even washing. It’s a lightweight structure without too much body, so it should withstand wind.
Add arches for climbing plants and hanging plants. Here the overhead canopy grid can be used for supporting plants or bird feeders, but you could also hang clothes out to air.
They also ingeniously created an extra layer underfoot. There is a grate paving grid suspended around 10cm off the balcony floor, with mosses and ferns growing through it. You can stand on it without harming the mosses and ferns. And the grid can be lifted to look after them. This creates extra greenery and growing spaces. Some birds also use the mosses as a nesting material, too, and there are other plants below the grid as well.
A grate paving grid allows mosses and ferns to grow on the balcony, but you can still step on it or sit outside. This is suitable for low growing shade-loving plants and helps increase the total amount of greenery in your atmosphere.
You can use standard garden arches, available in any garden centre. As designer Jason Williams did at Chelsea for his Cirrus Garden. It was based on the arches he used on his own balcony in Manchester, so he knows it works. He also added hanging baskets and shelves for pots.
Designer Jason Williams used standard garden arches in his balcony garden. They’re very similar to the arches on his own balcony in Manchester, which you can see on his Cloud Gardener website.
Or hang a grid on the wall for hanging tools or planters, as William Murray did in the The Potting Balcony Garden, sponsored by Viking.
Use a wall grid for tools and pots.
There is now a wide choice of vertical planter systems on the market. Some, such as this self watering pocket system, slot together and have a reservoir underneath each plant to hold water. Or there’s the Wonderwall system, and other systems are also rather like strips of pocket-size grow bags. It is, however, worth remembering that lots of little planters need more watering than a few bigger pots.
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Use colour for impact and definition
Take a lead from all four of the balconies at RHS Chelsea and use vibrant colour. It works well in small spaces and also in the open air.
Clockwise from top left: yellow and black in the Potting Garden balcony, brightly coloured pots in the Cirrus Garden, an immersive deep blue wall in the Blue Garden balcony and vibrant blue arches, grid and canopy in Angela and Alison’s Jay Day balcony.
Try using a strong colour like blue for window frames, railings or arches, like the vivid blue of Flock Studio’s bird friendly balcony.
Or go for strong contrast, like the yellow and black of the Potting Garden Balcony.
If you want to create a deep, immersive effect, try a meditative colour like deep blue or dark purple, as with the Blue Garden.
Or add colour with vibrant pots and planters in pink and orange, as in the Cirrus Garden.
What to grow on a balcony garden?
This is really the most important thing, says Angela. Not all plants will grow well on a balcony if it is very hot, very dry or very windy.
The RHS advises you to ‘choose appropriate plants,’ but what are those?
The most difficult aspect of planting a balcony is usually wind, so this post on the best windy garden plants and solutions will have some useful suggestions. Many trees won’t grow as tall in a windy situation, but as space is limited on a balcony, that’s a good thing. ‘It can create a beautiful natural bonsai effect,’ says Angela.
Pine and hawthorn are two trees that grow well in pots and are good in windy situations.
Drought-resistant Mediterranean plants, such as sage, rosemary, geums and lavender would be good too. Angela and Alison also included some easy-grow plants that are considered weeds in some places, such as marsh marigolds, herb robert, wild teasel and sweet woodruff. These plants are resilient enough to survive the more challenging conditions you may find on a balcony.
Plants that do well near the sea would also cope well with typical balcony garden conditions. Try fennel, verbascum or pelargoniums. There are more suggestions in my post on coastal garden plants.
But each balcony will have its own micro-climate, says Angela. ‘And it’s a small space. It’s not too costly to experiment to see what does well on your specific balcony. I’m a big fan of putting a lot of things on the balcony garden, and whatever lives, you get more of.’
There are ‘borders’ cut out of the grid on the Flock Studio balcony, with Mediterranean plants, such as Salvia nemorosa ‘Crystal Blue’ and Geum ‘Petticoat Peach.’
Don’t forget watering…
Watering is very important for all container gardens, because it’s hard for rainwater to get into a fully planted container. But balcony gardens are even more likely to dry out because the wind dries out the pots. And if you have a balcony above you, you won’t get normal rainfall on your balcony at all.
This makes it important to choose drought-resistant plants, although you will still have to water them regularly. Some people incorporate an irrigation system, but if you like moving pots round a lot that may be less suitable for you.
How to make your balcony wildlife friendly
If you want to attract birds to your balcony, bird feeders are the first thing that comes to mind. ‘And that’s important, but what’s almost more important is shelter’ says Angela. ‘If you’re a smaller bird with predators, you won’t eat in open spaces. You want to be able to get back to the shelter of trees quickly.’ They created a canopy overhead with the blue grid arch. Climbers can climb up this and offer protection from predators for feeding birds – and you can hang the feeders from it.
Joel Ashton made this point in his wildlife friendly garden tips. He says that many people are disappointed when their bird feeders aren’t really used. And it’s usually because there’s no safe haven for smaller birds close to the feeder.
Add bird and pollinator friendly plants too. Angela and Alison included a bug hotel in one corner of the balcony by piling up logs and moss.
One corner of the Flock Party balcony has a bug hotel of piled up logs. And to create even more planting space there’s a layer of planting on top.
Water is essential for any wildlife friendly garden area. You can have a small pond or water feature in a balcony garden but set it as close to the building wall as possible. That is where the best structural support is.
Place ponds, pots and water features close to the wall of the building as the structure is stronger there. This is the pond and waterfall in Jason William’s Cirrus Garden.
Balcony gardens and safety
I’ve already mentioned that it’s important to be structurally safe on the balcony by keeping the weight of the balcony garden elements to under 70kg per square metre.
And it’s also important to secure your pots and planters so they don’t blow or fall off. This could injure someone below or cause damage to cars or property. Don’t balance pots and planters on railings – make sure they are securely hung. Facing inward is safer than hanging them on the outside of the railing, and you will also enjoy the planting more.