So this project has 2 parts: A rooftop part that is out of sight to members of the public and patrons and a visible part, the outdoor space at the back.
The rooftop was something Karl had already made a start on with a few polystyrene boxes growing some ginger, spinach and parsley.
When Karl approached me about the job, he told me the roof was going to be a tough spot as it really gets nailed by the sun. He wasn’t wrong. It’s a tin roof and it really cooks up there.
As part of my response to the brief, I chose to continue with the polystyrene boxes because the garden was out of sight, polystyrene offers great insulation and of course, it’s a waste stream item for a restaurant. However, I realised due to a lack of handy water (the nearest water is the bathroom through the door down the hall a bit inside) that Sub-irrigated Planters (S.I.P.) or wicking beds were probably the best way forward.
The species getting the first run was basil (lemon, thai, sweet, liquorice), mint (apple and a variety already up there from Karl’s first attempts), lemongrass, pineapple sage, pumpkin, courgette, passionfruit and a rosemary or two. I like to try a range of species and then see what does well so that in subsequent seasons, those can then be concentrated upon. As we progress, cultivars can be varied and seeds saved to develop site-specific hardiness.
As the entire garden is sitting on a rooftop over the cool room and back room, I was concerned about the overall weight of the garden so decided that the soil/media needed to be lightweight to make up for the heavy reservoirs that would fill with water.
As it turned out, this may not have been the best of ideas – using perlite as a principle component in a garden bed system isn’t something I had done a lot of. I made some enquiries and thought I had it covered: 1/3 perlite, 1/3 compost, 1/3 potting mix. Sorted. Not quite. Pushing the sustainability envelope further I opted to use shredded paper for mulch and also some cardboard cut to shape in others. This on it’s own isn’t a bad idea but when combined with some less than premium potting mix – a bad idea albeit from good intentions.
I found the closest source of potting mix was the Coles in the Surry Hills Shopping Centre. Folks I’m here to tell you that their potting mix is terrible – lifeless sawdust with some finely grained black stuff, not really soil like at all. I thought my compost from home would make up for any shortcomings of the potting mix but this was not the case. It turned acidic.
After seeking some advice from a rather well known bearded fellow, I applied his advice of doing a soil test and making the appropriate pH amendment (as it was acidic, I sprinkled some dolomite lime, then applied cow manure and lucerne. Within a week, the basils were all leaping out of the planters. Success!