If hard landscaping forms the “skeleton” of the vegetable garden then the almost invisible irrigation system is its pumping “heart”.
In the early days of our vegetable garden crops weren’t as prolific as they could be because we often forgot to water, Gloria used to water the greenhouse using its water butts but in the summer these would last no more than a couple of weeks before they needed refilling and one day I “caught” her struggling to carry full watering cans down the garden…
From that point onwards I tried to make sure that the greenhouse water butts were never empty, topping them up with the hosepipe when necessary.
The greenhouse taken care of, we still had to water the rest of the vegetable garden. What we really needed was an irrigation system…
With a little help from neighbours, a narrow trench was dug and alkathene pipe the length of the garden buried. Coupling this to an existing outside tap at the house and fitting a tap at the other end in the vegetable garden put an end to “long-distance” watering can carrying.
Then, talking to Sam, a local lad who worked for his fathers’ landscaping business, in one of our local pubs one lunchtime I found out about “Orbit“, manufacturers of irrigation control systems.
A couple of weeks later I saw him again, only this time he sported a secondhand four-station watering controller which was “surplus to requirements“. After a short discussion and suitable exchange of “beer-tokens” it was mine.
Over the next few weeks, Sam helped me with the initial installation of the system. A pressure reduction valve was required to protect it from the vagaries of our water supply pressure, as was a manifold and some solenoid valves to control the actual watering, additionally, an adjustable rain sensor was added to stop “outdoor” watering when it was (or had been) raining.
The original second-hand plastic manifold disintegrated a few years later (I think it suffered from too much sun). Replacements were expensive so I started looking around for an alternative solution.
Searching the net, I discovered Solenoid Valves UK Ltd who had a wide range of suitable items, which I eventually narrowed down to some reasonably priced 24V AC Normally Closed 1/2″ Male Water Solenoid Valves. I made the actual manifold out of some leftover bits of copper pipe and plumbing fittings. This had the advantage of being able to fit the manifold with an isolation valve and being able to replace individual solenoid valves when necessary.
Running the pipework to the raised beds and the greenhouse was a nightmare. I ended up digging a couple of trenches across the entire plot and burying it. While everything was a mess I took advantage of the open trenches and ran an armoured cable to the summer house for lighting, a radio, phone chargers and the like.
The greenhouse had its own feed from the system and was wired to ignore the rain sensor. The other three stations watered the fruit trees, the 4′ beds and the 8′ beds. Organised this way we could ensure that the large beds received more water than the small ones, and by changing the settings on the controller the fruit trees only had water in high summer.
Each bed had its own feed pipe acting as a manifold to which the smaller watering pipes could be connected, and each watering pipe supplied between one and three adjustable mini sprinklers depending on the need. The greenhouse has a similar setup, which allows each plant to have its own sprinkler.
This keeps the amount of water used to a minimum, each plant receiving the water it needs just where it needs it.
For the future, I’m planning on experimenting with “leaky soaker hose” to look after the rows of salad crops, which I think may give better results than mini sprinklers, and micro misting heads for the seedling shelf in the greenhouse. (At the moment I still have to remember to water them by hand!)