Republic of Moreland

February 12, 2007

Backyard experiment

With Hydrocell, watered twice weekly

Without Hydrocell, watered twice weekly

In an earlier post, New ways with water, I spoke of the water-saving growing medium, Hydrocell. Its manufacturers claim its capacity to trap microscopic pockets of water and air promotes “Twice the growth, half the water.” So I gave it a whirl, and these are the results after two weeks on a water-restriction regime. The Hydrocell lettuces thrived: the control ones remained small, and some died.

As the beds are in different parts of the garden, it wasn’t a strictly scientific experiment. But each bed receives the same total hours of sun each day. The Hydrocell bed has a profile of only 10cm (the width of a fence post), as underneath I have a concrete garden. (Hydrocell is suited to rooftop gardens, being lighter than sand even when saturated.) The control sample is in a raised bed, but with a canvas barrier at 10cm depth, as I don’t trust the soil our house came with.

This is what the experiment bed looked like when I laid the first layer of Hydrocell. It has the consistency of flaky foam, and it smells like coconut. I covered the Hydrocell in a layer of organic compost and a mulch of pea-straw and lucern before planting some lettuce seedlings I’d raised from seed. (From Eden Seeds, a heritage variety.)

With the control model, I used compost and mulch with a layer of soil underneath, and planted the same batch of seedlings. On both beds, for the first couple of days I watered with stored rainwater, then watered with the hose twice a week.

The difference speaks for itself.


  1. Hey, are you sure you don’t work for this Hydrocell mob? And maybe that white stuff’s crammed with steroids. Ever thought of that? Maybe while you sleep those lettuce pull themselves out of the earth and prowl the garden, hungry for human brains. Several Coburg hoboes have gone missing recently, like that Mark D guy, f’r’instance…

    Comment by Bane of Malakas — February 14, 2007 @ 6:07 pm | Reply

  2. I tackled this question in an earlier post. I’m not on the Hydrocell payroll, but in the interests of disclosure, I did receive two sample bags through my involvement with Urban Agriculture/Green Roofs. 🙂

    Being the organic sort, of course I was concerned about what Hydrocell is made of. The stuff doesn’t contain any growth propellents: it just traps water and air. It’s 100% biodegradable and it’s made of proteins and resins.

    My garden is 95% organic, but I’m not a purist (to start them off, I fed the lemon trees with the Yates citrus food, for example. I use rooting hormone to help cuttings strike: don’t know if that’s organic). These lettuces wouldn’t qualify as organic, because Hydrocell is not a “natural” soil medium, but a manufactured one. I figure that since nothing in the product enters the plant, my lettuces are therefore organic. There’s a similar debate raging around organic hydroponics. Hydroponic lettuces fed with fish waste and pure organic solutions, for example, still can’t be certified as organic, even though they are free of chemical pesticides or fertilisers.

    I think products like Hydrocell, weighed up against environmental issues (lack of water), are an imperfect but good solution. It can be argued that solar panels take so much to manufacture that it’s not worth using them. Similar equasion here, I think.

    Comment by Girl on The Avenue — February 14, 2007 @ 7:09 pm | Reply

  3. They hadn’t heard of this at Nrth Fitzroy nursery. Do you know where to get it?

    Comment by Chloe — February 28, 2007 @ 1:22 pm | Reply

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