Automatic vegetable garden irrigation with rainwater and without electricity

Expected reading time: 6 minutes

What to do if the vegetable garden is not connected to water or electricity? The soil rummager has been thinking back and forth for a long time about how to implement his vegetable garden irrigation. Whether he should build a solar island system, or what alternatives are available. Finally, a sophisticated gravity-based system based on the hydrostatic paradox, pressureless bead hoses, and battery-powered irrigation valves has emerged. The photovoltaic system and a well were nevertheless added later – but not for watering the plants.

Why automatic vegetable garden irrigation?

Water is one of the most important resources in the vegetable garden. Without this, plants cannot survive. They need it to transport nutrients and to supply hydrogen and oxygen to build up organic matter. Depending on where we live, rainfall may not be sufficient during the summer months, when the need for water is highest – especially for highly consumptive plants such as zucchini, squash or tomatoes – so we have to water our vegetable beds. When the sun is shining and it is accordingly hot, it may well be necessary to water daily so that the vegetables sprout and thrive.

But what if the gardener – as well as the soil digger – does not have time every day to water in the garden? Here then very quickly comes the question and the desire for automatic vegetable garden irrigation. In the meantime, there are, for example, a large number of ready-made solutions from Gardena with watering computers *, which can simply be connected to the water tap and are time-controlled via different Sprinkler *, Valves *, hoses * and drippers * deliver the optimum amount of water to the vegetables. But what to do if the necessary infrastructure is simply not there? For example, many allotment gardens have neither water supply nor electricity. So the first question arises very quickly here:

Where do I get the water for my pressureless automatic irrigation and how do I store it?

The answer is quite simple and obvious: collect rainwater! Of course, some infrastructural requirements have to be met for this as well: First of all, a sufficiently large roof area is required (it may be possible to tap into the neighbor’s roof area) as well as a reservoir in which the collected water can be stored in order to survive a more or less long dry spell (depending on the size of the reservoir).

How do I distribute the water without electric pumps, i.e. completely pressure-free?

Excursus: the hydrostatic paradox, principle of communicating tubes

The hydrostatic paradox is based on hydrostatic pressure. It states that the liquid level in interconnected vessels – regardless of shape, volume or cross-section – is the same. It was formulated by Blaise Pascal, who is also responsible for numerous other discoveries in physics. This principle is also used in the Hose Scale * is used.

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Practical implementation

The soil digger has been racking his brains for a long time on how to transport the water cleverly and without much effort from the roof of the garden shed and the storage tank there to the vegetable patch to feed the automatic irrigation system. Of course, the whole thing should be done automatically and not by (electric) pump or even dragging buckets or cans.

For this purpose, an IBC container * with 1000 l capacity by means of PE water pipe * with three commercially available rain barrels * (200 l each) connected. Thus, a total storage volume of about 1600 liters is available.

So now when the rainwater from the gutter runs into the IBC container, the water level in the connected rain barrels automatically equalizes and the water from the roof is distributed to them.

From the rain barrels now go per bed per Standard Gardena connection* commercially available garden hoses * from. The Gardena connections and everything behind them are best cleaned with a strainer with 3/4-inch external thread * protected from coarse contamination. These standard hoses are in turn mounted on pressureless functioning bead hoses * after a finer flow filter * removes finer particles and thus protects the bead hoses from clogging too quickly. The advantage of these hoses is that they can be laid underground, which on the one hand avoids excessive evaporation, and on the other hand the water is directly where it is needed: at the roots of the plants. This allows the stored water to be used optimally and vegetable garden irrigation becomes very efficient.

The bottom rummager says:

If you don’t have to carry cans, you don’t make a fool of yourself either

How can I realize a time control?

Now that the system automatically collects, distributes and delivers the water to the plants without our intervention, there is really only one important step left: how can we regulate the amount of water and control the watering time and duration without being on site?

Here, too, there is an amazingly simple as well as inexpensive solution: battery-powered irrigation valves with timer. *. These include a timer that determines the time and duration at which the integrated ball valve is automatically opened or closed again. They are powered by commercially available batteries (or rechargeable batteries), which last a pleasantly long time.

Material list

• Rain gutter*
• IBC tank*
• IBC connection pipe with filter sieve*.
• IBC ball valve*
• 25mm PE pipe*
• Rain barrels*
• Connector for the PE pipe*
• Gardena connections*
• Garden hose*
• Battery operated ball valves*
• Screw sieves 3/4″ male thread*
• Inline filter*
• Peristaltic hose, unpressurized*
• T-pieces for bead hose*
• End plug for bead hose*

Summary and presentation of the result

Even this solution is certainly not completely cheap in its entirety. Nevertheless, you save the cost of installing a power connection, remain completely autonomous and work very energy efficient.

The solution of automatic vegetable garden irrigation presented here has now proven itself for three seasons, so can be recommended with a clear conscience. If you are also interested in macronutrients and fertilizers or building a greenhouse heater, feel free to browse our site some more.

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