The Ins and Outs of Wall Gardening

Sometimes when space is lacking, your only option is to go up. George A Fuller – the inventor of the modern-day skyscraper – was well aware of this. He showed that you’re not limited by ground-level real estate; rather, you’re limited only by imagination, engineering and cost. The same applies when creating a wall garden.

The popularity of wall gardening has grown as our big, spacious blocks fall by the wayside and growing things vertically now occurs more through necessity than just gardening freestyle. Growing things up a wall, or hanging over a railing, or on top of your head if you wish, are ways of chasing the sun to grow food. As the winter sun further lowers in the northern horizon, chasing it up a wall may be the best - if not only - way to grow through the cool season.

But anyone who has tried to create and then maintain a wall garden - like the one they saw on display at the garden show - would know that success doesn’t come easily. That is because to minimise loading they are often constructed from low-volume, shallow containers, and are thus afflicted with many of the issues that challenge pots. So getting them started is easy, maintaining them however is different proposition. This may just explain the rise of the fake plastic wall gardens - have you noticed them too?

In any wall garden getting adequate nutrition and moisture to the plants is a constant battle. The more confined the growing space, the less nutrition there is for the plants and the greater the rate of evaporation. In wall gardening this presents the ultimate Goldilocks conundrum: finding the pot size that is just right. That is, the size and depth to grow the plants you want, but without bringing the wall tumbling down.

Most wall garden modules are no more than 15 to 20cm deep, which limits the types of plants that you will succeed in growing. In terms of edibles this excludes growing most perennials or larger style plants, making them more suited to shallow rooted and fast growing leafy greens.

When opting for ornamentals, we’re hit with the same snag. But the main consideration for growing ornamentals - many of which are perennials - is finding a space that is going to work in both winter and summer. These warm blooded plants want a well lit, protected wall that is not too cold in winter, nor too hot in summer. Yet another Goldilocks conundrum.

But good things are never meant to be easy, and nor should they come without some work - that’s what we call satisfaction after all. So here are some things to consider when setting up your own wall garden, to ensure the chances of success are in your favour;

Choosing a Wall
Choose a wall that receives sufficient light and for edibles is north-facing so it gathers the lower winter sun. If you have many sunlit walls, choose one that takes in the gentler morning light rather than an afternoon heat trap. If you’re hoping to grow ornamentals - which will require less ongoing maintenance than edibles - you want to avoid direct sunlight and find a well lit, protected space. One that is warm in winter and cool in summer….a sun room is perfect.

Accessibility 
Let the height of your wall be determined by what it can hold and what is manageable to harvest and tend. While the idea of a ladder to gather food seems plausible when your enthusiasm is at its peak, harvesting quickly becomes a chore. I’ve personally learnt this the hard way and once invest too much time and money into a rooftop garden I was certain would become a favoured hangout space, but instead became a jungle of weeds.

Watering
Wall garden units tend to dry out very quickly and so irrigation is highly recommended – almost essential. Watering daily during winter and twice daily in summer is par for the course. So if you have a job, a family and a few friends, and you wish to maintain all of these things, it’s probably best you’re not manually watering your wall garden. A simple drip irrigation, affixed to the top planters, should be able to use gravity to feed water all the way down to the bottom. If your garden is set up in a semi-indoor area, some consideration for the overflow of water will be necessary.

Potting Mix & Fertiliser
It pays to start off with a good quality potting mix that is high in fertility and able to hold moisture well. Quality in terms of potting mix is correlated to price, so don’t skimp on the cheap stuff because you’ll be fighting a losing battle from the outset. More regular feeding is essential for maintaining healthy plants. When growing edibles apply a fortnightly dose of seaweed extract and monthly fish fertilise.

Plants
Shallow soil depth limits the types of plants that you can successfully grow, whether you’re looking for a productive or ornamental style wall garden. Here’s some of the more suited varieties;

Productive plants

• Strawberries
• Salad greens - Lettuce, Rocket, Radicchio, Spinach
• Edible flowers - Nasturtium, Viola, Marigolds
• Annual herbs - Basil, Coriander
• Some perennial herbs - Thyme, Oregano, Parsley

Ornamental plants

• Ferns - Birds nest, Asparagus, Boston, Spider
• Bromeliads
• Vines - Devils ivy, Philodendrons, Succulents, Cacti

Types of Wall Gardens
Without doubt the easiest way to start a wall garden is to buy modules designed for the job, but if your DIY nature won’t allow it, here are some materials that can be converted; Rain guttering: more suited to productive style of wall gardening, rain guttering is durable and has a depth great enough for salad greens.

Pallet: with a few alterations, a pallet can become a more rustic style of wall garden, best suited for succulents or kitchen herbs if you’re willing to maintain

Milk crate: Melbourne’s coffee culture means that all the materials are there at our fingertips; a stray milk crate, lined with a hessian coffee sack and an ’S-hook’ to hang. The greater planting depth increases your scope of plant life.