permacultura-urbana

Secchi auto-irriganti

A garden that you don’t have to water.

A garden that you don’t have to water.

Tomatoes, lettuces, strawberries, cucumbers, onions, basil all flourishing and thriving. You would never tell that these crops have never been watered for the past 2 months, exactly since we built this system and planted them in place in the beginning of April.

What I’m going to describe you is a low maintenance automatic system that not just eliminates the need to manually water the plants but it manages to give them the water they need when they need it, making the plants more productive. Immagine a system the regulate itself, no more guesses, no more worries, no more plants dying due too little or too much water, no more time wasted doing this repetitive and boring task.
All time saved that you can spend really enjoying your garden, visiting at your own desire to check your plants and harvest your crops. Is it not what you want, a more productive garden that needs little maintenance, and let you more free time to enjoy the benefit of it?

This project is particularly ideal for city dwellers with limited space, time and gardening experience but that want to grow some of their food. It is a diy solution that you can easily build in your garden, balcony or any space you have available.

The main idea comes from a diy project called alaska self-watering buckets (link) onto which I made some design changes and improvements to much it cheaper and more productive.

So, what a self-watering bucket and why use it?

A self-watering bucket is a container consisting in a top layer of soil and a bottom layer of water. Between these two layers, a mesh or perforated material holds the soil apart while allowing some of the water to get in contact with the soil.

A self-watering bucket has 4 main advantages:

A Bottom up irrigation.

The water on the bottom acts as reservoir that the roots system can always tap into. The plant therefore, auto-regulate itself getting the water it needs when it needs it. It also reduces the evaporation of the water, keeps the soil moist but not wet, avoids over-watering and leaves the leafs dry preventing deseases.

Water reservoir.

Depending on the size of the container you are using and therefore the reservoir you have, your plants will have enough water for days or even weeks. As long as the reservoir has water in it, you don’t have to worry about watering them, so you can go on holidays without expecting to find your plants dead. Just keep on eye on the water in the reservoir and refill it when low and you are good to go for another while.

The right amount of water.

Plants self-regulate themselves. They know much better than us how much water they need it and when they need it. With this system they take these decisions by themselves removing an other weight from the gardener shoulders.

No energy need it.

This solution is totally energy free, no electronic devices are needed to pomp water, so no worrying about mulfunctions or power cuts. It can be place anywhere.

Sounds like a pretty fantastic system but how can we make it even better and even less work? We can improve the reservoir efficiency reducing the times even more the need to refill.

Creating a self-watering bucket that self-refill itself or that stays always at the same level.

On the Alaska self-watering buckets, the reservoir of a series of bucket is connected to each other through a pipe and put on the same level. Liquids in connected containers stay always at the same level. When water is used in any of the bucket, the level in all the bucket will lower.

These bucket are also connected to a main bucket, filled just with water, that acts as monitor of the water status inside the buckets. The water level in the main bucket will be the same of the level in all the buckets.

As now we have a way to have the same amount of water in all the buckets and see how much is it in, but how we refill them? The main bucket is connected to a big tank storing hundreds of liters of water. This tanks is raised few centimeter higher than all other buckets allowing the water to flow from the tank to the buckets using gravity. The tank fills the main bucket that fills the other buckets. To prevent the tank to continuously flows water in all the buckets making them full of water, a floating valve, similar to the one in the toilet flush, regulates the flow. The valve is placed at connection between the tank and the main bucket. When the water reaches as certain level in the buckets, the valves closes the flow and opens up again when some of the water has been used.

Using this system we have actually created a system with a reservoir of hundreds of liters of water that can auto-refill multiple self-watering buckets at the same time. Cool right?!

Some of the advantages of this system are also:

It’s easily scalable. You can start with one or two buckets and then scale up to as much as you want. To add another bucket to the system you just need the basic construction components like the bucket, and the pipes.

An Alaska self-watering container is already a cool improvement to a simple container gardening but how can we make it even better? Here the improvements that I made to the system.

Different holding medium. In the original design the soil and the water where separated using a colander and a cotton bag. While I find this solution easier to use and lighter, I found it relatively expensive and not applicable to container of different size. What I created is a donuts made with a perforated pipe, you can buy meters for few €, and used a piece of cotton to prevent the soil to go inside the holes.

Bigger buckets more plants. 5 gallon buckets are good for mainly any type of plants but that means that you will have a bucket for each plant, exponentially raising the cost of the material. I opted for big 200lt used bucket that I cleaned and cut in half.

Companion planting. Some plants grow better and get mutual benefit when close to each other. Benefits include pest and desease prevention, exchange of nutrients and creating microclimates. Before planting, check what to plant as some plants instead can compete for the same nutrients and therefore not growing.

Vertical Gardening. I try to make maximum use of the space I have available so, a big bucket means also some growing space on the sides for more plants.

Direct fertilization. As the main tank is the water storage and fills all the other buckets, putting some fertilizer in that water will slowly leak that nutrients into all the buckets of your garden.