Saturday, 26 May 2018

The Oasesbox irrigation system

A few months ago I was kindly given a set of "Oasesboxes" for review, and now I am putting it into action.

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 centre.

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.


  1. Hello Mark!
    I can see that the planting box's design would save soil/compost, but the water level measurement is rather iffy. The planter box I bought has a small hole on the side at the top of the water reservoir. So a person can add water until it begins to trickle out the small hole and know the water is at the correct level.
    Happy Gardening!
    Lea in Mississippi, USA

    1. Yours sounds like a much better arrangement, Lea.

  2. I wonder if the plants will become pot bound if there is so little soil on the funnel. It will be interesting to find out. My guess is that it would work out to be an expemsive solution if you wanted to grow lots of plants using this system.

  3. Mark, three hints from my recent experience with this method:

    1. The standing water in the reservoir is a great mosquito breeder. I never thought of that when I bought it. Do you have mosquitoes?

    2. Be sure to pack the compost in very tight at the bottom. It compacts when it gets wet and doesn't always reach the roots after that. I had to water the young plants from above for awhile until they got large enough. On hot days you may have to add additional water from above. Although I doubt you'll ever get a week of 90F degrees.

    3. It looks to me your plants could very easily become waterlogged. If that happens, you can drill some holes about four inches high above the ground. I had to do this with some so called self watering pots, but only after I lost some plants. Wilting in these cases is caused by either too little or too much water.

    I tried three new and different methods this year: growboxes (like your Oases), fabric bags, and self-watering pots. None of which worked in my hot and dry climate. It amazes how manufacturers can get away with this hype selling these things that don't work properly. There is considerable cost involved. I am quite disappointed. Buyer beware.

    I am going back to using the old pots with a saucer at the bottom. Very visual water supply.

    Keep us up-to-date on how well this system works for you.

    1. I want to add some more comments:

      4. The dipstick method of measuring the water is way too fussy for me. I would never use it.

      5. If you add dry fertilizer on the top, you have to carefully water it in for a few days. If you add it with the water, it has to be very soluble. Better to dissolve it in a watering can first. The correct fertilizer is the key to success here I think.

      Most of the plants are thriving.

    2. Thank you for going to the trouble of giving me / us this very comprehensive feedback. I have to say that I am also an advocate of the old methods of watering too - I like to SEE how things are getting on. I don't think I would have bought any Oasesboxes, but since I got them free, I'm going to give them the benefit of the doubt - at least once.

    3. Hi Mark,
      thanks for the review and also thanks for all the constructive comments and suggestions I read. I'd like to add my thoughts and personal experience with the Oasesbox since I helped to develope this self-watering system. Develpement partly took place by planting in these boxes all sorts of veggies and flowers, water-loving plants and plants who prefer to have it more dry, keep them outside in direct sunlight and heat, or leave them also in the cold.

      The prime incentive was to keep the design of the Oasesbox as self-watering system and how to use it as simple as possible, as practical as feasible to have a very efficient package. As the working principle, the water is drawn up through the soil to the plant and the plant takes as much as needed. For this reason, it is correct, when filling the cone with compost, you need to compact it otherwise one leaves gaps for the transport of the water up to the plant. With this design, one can water-log the entire system when having too much water in the reservoir. This can also happen, if the plant takes up too little water! Too much is a relative thing. For a tomato or a cucumber plant, in particular when producing fuits, too much is not that much of an issue. When refilling, we often go for about 10-15L max, in particular when the plants are located in full sun light during summer. The plants take quite some water during that time. Under these more demanding circumstances, the water reservoir will last up to a week. Otherwise up to two weeks. On the other side, a pepper or chilli plant likes it dryish and when refilling, we refill at most half full. Not more. For these kind of plants, the water in the reservoir can last somewhere between two and four weeks. We usually make certain that the top soil stays dry. This is also a sign that there is not too much water around and the box cannot get water-logged. To cut a long story short, the optimum water level in the reservoir depends at the watering needs of the plants one keeps in the Oasesbox. And most of us know by experience which plants require more water or which ones like it more dry.

      Some comments are about the water meter and also, that one has to figure out for one-self how much water is good for the plant, or how much is too much leading to water logging. The home-made water meter, best printed on a card-board, or just take a strip of card board, will only give you a good idea how much water is in the reservoir. No more, no less and in the very most cases this is sufficient to know. With time, we changed to simply lifting the box a little and gauge this way how much water there is and if a refill is needed. I don't think that one has to drill holes as an overflow. Just don't put in as much water into the reservoir, the plant will do fine most of the time.

      Fertilizer is a good point. We also take liquid fertilizer and put it directly from the top. With time the plants take it. When putting liquid fertilizer into the reservoir and the water uptake is slow, there is a chance that the water in the reservoir could become stale.

      Mosquitos are not that much of an issue in central Europe. Though, this is a point we need to think about what could be done as a simple to use add-on. To test the Oasesbox in a very hot and dry climate is somewhat difficult to realize for us. Last summer was very warm (several weeks with more than 30°C and above), and dry and we had all our plants on our terraces with little natural shaddow. Most of the images on the Oasesbox webpage are from these plants. We didn't had the impression that the plants suffered too much when left out in the heat.

    4. Sir,

      I am impressed by your conscientious reply as a developer to the comments above.

      I like the idea of the water in the reservoir lasting a week or more so that someone could take a vacation without being concerned about their plants.

      To give you an idea of the extreme end of the range of water need, I have a box 24 inches in length with six squash plants as recommended by the maker that took up four gallons a day during hot and breezy weather in southern California.

      Again, thank you for your considerate response.

  4. I use this type of self-watering These are nice because you can put it in any existing container. A similar system would be easy to build out of plumbing supplies. I've found that once the reservoir fills up, if you don't quit the container continues to fill until you can see moisture coming up from below. Which isn't a bad thing. You know you've soaked the soil from the bottom up. No more guessing how deeply you watered

  5. detailed information about irrigation system
    I love this idea! We travel quite a bit and a neighbor waters our plants for us. We could do this instead and save so much time and I wouldn’t worry about forgetting to water too. Thank you!

  6. I've marked a white plastic ruler with a permanent marker at what I think are the 5/10/15 litre levels. The rulers centimetre marks will help in-between measurements. Obviously,I'll use it as a dipstick. Am interested to see how I get on as I've only just purchased my boxes.

  7. What was the overall result of your trial of these boxes please? Am looking at various options for growing tomatoes in the greenhouse this year - I usually use the large size growbags

    1. Hi Geri; To be honest, I wasn't overly impressed with the Oasesbox system. I prefer the old-fashioned methods, using soil! The plants I grew in them did no better and no worse than I would have expected. At £20 each, this is an expensive option and to justify the expense I would need to see a huge improvement in yields, or something. The convenience of not having to water the plants so often is the only advantage I can see.

    2. I am trialling oasesbox and easy2grow this year. Last year my hozelock auto watering system did not cope with the hot weather and I got wilting and blossom end rot. Letting the plants have water available all the time so they can choose when to drink, will hopefully solve these problems. Yes they are pricy to buy, but it’s a small cost compared to the cost of buying the greenhouse. Gardening is not a free hobby. It’s worth paying for the pleasure it brings. Cheaper than a season ticket to the football! I will let you know how I get on.


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