Flower bed Irrigation

The simplest way of watering your garden is by filling a watering can and pouring water on to your plants. Fortunately engineers and inventors quickly got bored of this very time consuming method and devised a whole range of irrigation systems.

Let’s start with the tap in our back garden onto which you can attach a whole array of timers and simple flower bed irrigation systems.

There are so many tap timers on the market and new ones coming available every season that I will not try and suggest which one is the best but do look out for the following features.

1.  Can you set the time at which timer turns on the water so that you can program it to come on during the night when there is more water pressure
2.  Frequency. - How often can you have the timer come on? Is it pre-set or can you decide?
3.  Duration. – Can you set the duration or are they pre-set
4.  Easy to programme.
5.  Does the timer have more than one port? In other words can you water 2 areas at different times for different lengths of time

Amico+ tap timer with 2 ports

Most tap timers have just one port and that is fine if you only want to water a flower bed that requires the same amount of watering. If you want to water a flower bed and hanging baskets the water requirement for the hanging baskets will probably be daily watering and the flower beds will could be only once a week so a dual port tap timer would be the one to go for.

Once you have decided on the tap timer, you will need to start designing your system and decide which materials you are going to use

Let’s start with a flower bed, with average good loam soil that you want to water when on holiday this summer. I would lay a drip line along the length of the bed 15 cm to 20 cm from the edge and space the lines about 30 cm apart this would give me 6 lines of drip line pipe. The drip line has drippers installed every 30 cm so this would give me adequate water coverage.

Now I need to know if there is enough water flow from the tap to supply all the drippers in the pipe. The flow rate of each dripper in a standard drip line is 2 litres water per hour. 

My calculation would be as follows 6 line x 5 meters = 30 m of drip line, and the drippers are spaced at 30cm along the pipe 30m divide by 0.3 meters = 100 drippers. Each dripper emits 2 litres per hour so 100 x 2 = 200 litres per hour. 

How much water does the tap give? To find this out you can measure the flow of your tap using a 10 litre bucket and measuring the time it takes to fill the bucket.

If it takes 30 seconds to fill a 10 litre bucket, divide 10 by 30 to get the number of litres per second, multiply by 60 for the litres per minute and multiply again by 60 for the litres per hour.

10: 30 = 0.333 litres per second, next 0.333 x 60 = 19.98 litres per minute and finally 19.98 x 60 = 1,198.8 litres per hour. This gives us plenty of water for our small flowerbed irrigation.

www.arcadiairrigation.co.uk