My new house has a “smoking balcony”. It’s barely big enough for two dining chairs, with no stairs and only a door to the kitchen. It’s functionally useless except for smoking, so I’m turning it into a ‘living pantry’ - a small garden of edible plants all contained within planter boxes and pots. The idea is that I can go out there at any time of night in any weather to harvest just what I need for a meal or drink. The balcony gets sunlight for the first half of the day, but is under cover and against the house to protect against strong winds or excessively heavy rain. One edge of the balcony gets sunlight until about 3pm, so I can keep cherry tomatoes on the same balcony with all the herbs.
I began with self-watering planter boxes. They work by having a grill in the bottom of the box. The soil is held above the grill, and beneath the grill is an area for water to sit. There’s a drain hole to keep the water at a maximum height, and dips in the grill to allow small areas of soil to be wet. The water wicks up through the soil to feed the plants.
Here’s a diagram of how they work: http://www.zerosoilgardens.com/wp-content/uploads/2014/04/self-watering-planter-diagram.jpg.
The pros are that the soil remains at optimum moisture, allowing the roots to absorb as much water as they need without the risk of being drowned. The water reservoir also means watering can be done as infrequently as every few days. The major con is that water-mixed fertilizer can’t be used (it will just oversaturate the reservoir and poison the plant), so de-potting the plants every year or two to replenish the soil with nutrients will likely be necessary.
I quickly found that filling the water reservoirs from a jug was inconvenient, so I started to work on an automated watering system. Also I just always wanted to make one 
. Since I have self-watering planter boxes, I don’t need spray nozzles or drippers. I just need to be able to automatically refill the reservoirs every day. It should be far easier since I only need to have the valve open once a day for a preset time, and there’s no guesswork on how much water they need. If my program over-waters, it will just overflow. I might add an overflow sensor to stop watering since excessive overflow can wash out nutrients from the soil, if I can be bothered.
Here’s a photo of my progress so far.
From left to right the plants are garlic chives, sweet basil, mint, cat grass, and four different varieties of cherry tomatoes. It’s only been about two weeks and the plants have all doubled in size. The mint is looking small but that’s because I’ve had a lot of mojitos
. I might need to re-pot the cherry tomatoes later on if they get too big. For now I just have an attachment to plumbed water that requires me to turn on a tap. This flows into an adapter to 5mm PVC tubing, teeing off to each planter box. I drilled a hole in each and just jammed an elbow joiner into it. Since the boxes are polypropylene the hole is stretchy enough to not leak even without glue. Laziness wins again.
Future goals:
- More of the same planter boxes with parsley, spring onions, and chilies.
- A rack to hang the boxes on the railing where they’ll get more sun.
- Automated shutters with an airspeed sensor to protect the plants from storms and strong winds.
- A solenoid valve on a timer to refill water automatically.
Thanks for reading. As a reward for getting this far, I give you a life hack. How to protect your hose from being stolen and chopped up to make a bong when you live in Ipswich: a sacrificial decoy.
