Beautiful vertical gardens. Lush, green walls with all our favourite plants, suitable even for the smallest balcony or courtyard. Don’t we all want one?
Following the Australian Garden Show Sydney earlier this month, there appears to be one feature that has stuck in the minds of most attendees. Clients and friends all seem to be talking about vertical gardens. Which worries me a lot.
I don’t actually know a single mad keen gardener that has one. We all oo and ah over them but you wouldn’t catch us actually installing one in our gardens in a million years. And yet we are the only crazy people who should probably have them.
You see vertical gardens are about as high maintenance as you can get. Essentially you buy 100+ teeny weeny, fragile plants in tiny pots and then commitment to nurturing each on an individual basis forever more. The campaign ‘a dog is not just for Christmas’ has nothing on this!
Each and every plant has a tiny pocket of soil which dries out within seconds of the sun coming up and expects you to stand there drip watering it all day long. But give it one drip too many, or one drip too early and the peat-free potting mix will clog up and kill those plant roots before the week is out.
And whilst you are thinking that your automated watering system will do all that for you whilst you sit in your reclining chair, have you ever noticed that watering systems are not very good? They don’t know if it’s been 40 degrees or 20 degrees that day, they don’t shout when one of the holes gets blocks and desicates huge chunks of soil and most don’t turn off during torrential downpours. Whereas soil in the ground, perfectly fit for its job, will drain nicely, give plenty of space for roots to grow towards moist areas and be resistant to drying out by its sheer volume, our vertical garden isn’t capable of any of this.
Next comes fertilising. Clearly with such small volumes of soil the pockets are very quickly exhausted of nutrients. So we have to keep feeding them. Whatever you do though, don’t feed them too much. With small volumes of soil and imperfect drainage it is incredibly easy to overfertilise, producing toxic conditions.
And we haven’t yet touched on pruning. Have you noticed that your 100+ plants are not robust shrubs that are happy with a quick bit of secateur action once a year? No, they are herbs, annuals and ferns, most of which need either pruning, deadheading or de-leafing on at least a weekly basis. But not with my succulents, I hear you say. Oh no, no pruning there. The only thing that you will need to do is replant the whole structure twice a year due to soil compaction.
I love anything that gets a non-gardener excited about gardening, but vertical gardens scare me. I can see all these keen, inspired, starter gardeners going out and buying their lovely green wall kits. They spend a small fortune, almost get a divorce trying to attach the frame to the wall and just one month later their beautiful garden is looking terrible. They will never want to garden again.
There are so many better ways of creating a green backdrop, even when you only have a few centimetres of depth. Star jasmine (Trachelospermum jasminoides) is a wonderful plant across most of Australia. With just a couple of plants and a few horizontal wires (every 30-40cm) it will fill a wall completely and smother you in beautiful scent for much of the year. I also love this creative idea by Matt Coggan using star jasmine as a green curtain.
The wires are attached at the top to a rail and at the bottom to the pot and you can move your screen wherever you want privacy or shade. Ingenious. Please use bigger pots, for all the watering and fertilising reasons we have just discussed, but what a fabulous idea.
Alternatively, espalier a plant. A single shrub will fill a wall and be the ultimate in sophistication, using the right frame or ties. It may look tricky but it really isn’t. It just needs 5 mins attention every few weeks during the growing season to cut and tie and you are done. Other that that you just treat it exactly as you would a normal plant.
And if you really want some beautiful small plants on your wall, place them on a stylish shelf. Looking after 3 small plants is significantly less time consuming than looking after 103 of them!
So please don’t rush out and buy your vertical garden, unless you are sure you want to give it love most days. There is a place for vertical gardens, but I say leave them to the super time-rich and the Qantas lounge for now.