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How to Make a Simple Greenhouse Automatic Watering System

An automatic watering system for the greenhouse doesn't need to cost a fortune. In fact, they are very simple to make, and once set up, will allow you to get on with other things, or even go on vacation, knowing that your plants will not shrivel up and die through lack of water while you are away.

Greenhouse plants, as we all know, need regular and frequent waterings especially during the hotter days of spring and summer.

When you think of irrigation systems, especially automated ones, you think of lengths of tubing and expensive timers, all connected to the water supply that you may or may not have in your greenhouse.

With the system outlined in the video above, you can carry the water into the greenhouse from elsewhere, as once it is in the container you choose to use as a reservoir, it will only need the occasional topping up.

The bigger the reservoir, the less often you will need to replenish the water.

You can buy the parts at Amazon if you don't already have them lying around

What you will need for an automatic watering system

  • a greenhouse bench, or board with sides on which to place the plants. This will need to be above floor level, and higher than the top of the reservoir, so that gravity will pull the water back into the reservoir container.

  • a container to act as a reservoir - a plastic drum of some sort is perfect. You can even cut the top off the drums industrial liquids are stored in. A large bucket would even do, at a pinch. Raise it up to just below the level of the bench by positioning it on upturned clay pots or bricks.

  • a short length of garden hose to attach to the pump for the water to travel along and on to the surface of your bench or board.

  • an electrical power point in your greenhouse - this is a necessity to run the water pump.

  • an electric timer switch to turn the flow of water on and off.

  • a water pump designed for something light, like a small garden pond or fish aquarium

  • a length of horticultural black polythene. This type of polythene is thicker and sturdier than the type used for garbage bags and the like.

  • a length of capillary matting - this is great for absorbing liquids and holding them for plants to get a greater use of, long after the rest of the water has drained away.
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Put your irrigation system together

  • On top of the bench place a double layer of black polythene, making sure it reaches all the sides. This is to stop water from draining away naturally.

  • Place the capillary matting on top of this.

  • Attach the hose to the pump, and place in reservoir.

  • Fill the reservoir with water until it is around three quarters full.

  • Plug the pump into your timer switch, and set it to come on for a minute or two, twice day, or more often if you live in an area of extreme heat.

  • Each time the pump runs, water from the reservoir will wash over all the capillary matting area, then return to the water container it came from, minus, of course, what your plants have drank and a little bit more that is absorbed by the matting.

  • It takes typically less than a minute to thoroughly wet the whole area, in what could be called a flood wash watering.

  • You can even add liquid fertilizer to the water, to make sure your plants have all the nutrients they need.

This automatic irrigation system is simple to set up, inexpensive to prepare and run, and absolutely anybody could put it together, no matter how untechnically minded you are.

Go ahead and fit one up - your plants will love you for it!

greenhouse plants on self watering irrigation system

greenhouse plants on self watering irrigation system


GardenExpert999 (author) from Scotland on May 08, 2012:

You're welcome. This watering system saves a lot of time and effort :)

bythewhat from USA on May 07, 2012:

I love anything that has to do with gardening, thanks!!

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