The Oasesbox self-watering planter system is one that I would describe a semi-hydroponic. This is how it works:
The basis of the system is a stout square plastic container (they come in green, grey, black or terracotta colours) which acts as a water reservoir, holding up to 15 litres of water.
Into the container sits a shallow soil / compost tray with a deep cone-shaped funnel in the center.
The bottom of the cone fits quite snugly over a boss in the base of the reservoir, so that compost does not fall into the water, but water can seep upwards into the compost through capillary action.
The tray and funnel are filled with soil, and your chosen plant is planted into it. Water is added to the reservoir via any of the holes at the top of the sides the reservoir. The plant's roots then grow downwards to the water, guided by the smooth tapering surface of the funnel. Allegedly it can be as much as four weeks before more water needs to be added, but I'm sure the rate of consumption depends on the type of plant being grown. I have put a Cayenne chilli plant in my first one, and the next one will hold a tomato plant.
The design of the containers is such that they can easily be slotted together in various configurations.
I have joined my three together for this photo, but I think I will actually use them separately.
I think the most difficult aspect of using this system will be judging how much water each plant should have. The kit's instructions give some general guidelines, but I suspect it will be just a case of trial and error. It's quite difficult to see how much water there is in the reservoir - maybe they should be manufactured at least partially in transparent material? In the kit's instruction manual there is a page marked out to indicate filling levels. You are supposed to paste this paper page onto 1mm cardboard and cut it into strips which you then use like a dipstick to see what the water level in the container is! This seems far too rudimentary to me, and I'm not sure how well it will work.
Anyway, "the proof of the pudding is in the eating" as they say, so it will be interesting to see how the Oasesbox system performs in comparison with my usual growing methods. I'm already thinking that if it works well one big advantage is that it uses a very small amount of compost. Modern commercial compost is not only expensive but also very often of poor quality (let's not mention the weedkiller contamination issue!), so the less of it I have to buy, the better. The big attraction though is the fact that the water in the reservoir should last for quite a while, making this product ideal for keeping plants properly hydrated even when you are away from home.
The triple pack of Oasesboxes is available from the company's online shop, priced at £44.99, and a single one is £19.99.
Disclosure: I was provided with the triple Oasesbox kit free of charge, for review purposes.