Most gardeners are keen to do their bit for the environment. Often they will have a compost bin and a water butt to help sustain their plants while cutting out the need for chemical feeds and adding to their domestic water bills.

The trouble with butts is that they have to be connected to a source of water such as the gutter on a shed and often lack the capacity to irrigate a large garden, especially in hot weather.

And they are not the prettiest of features either.

These were problems identified by Lewis Oakley (pictured) as he worked for Oxfordshire clients running his Headington-based GardenMaintain business.

While laid up with an infection over Christmas, he came up with the idea of creating an underground storage tank connected to a “village pump” feature which can then be used to fill a watering can.

The tank, which holds up to 220 litres, is fed through gravel via a filter and does not have to be connected to guttering, although this is still possible.

The result is a large capacity self-sustaining reservoir for watering that can also be used as an attractive feature for the garden.

He said: “While I was ill I started wondering what I would do if I could not go back to gardening and I came up with this. When I was feeling better I dug a hole in the garden, built the system and it worked really well. It is very simple, looks good and is environmentally-friendly.”

Mr Oakley, 38, hopes to develop the pumps — available in a range of colours — so they can be sold through garden centres and also believes a franchise operation can be set up to sell them nationally. And although they are not cheap at £599, they are built to last and Mr Oakley believes they will be attractive to home owners with large gardens in wealthier areas.

It is not the first garden-based design Mr Oakley has come up with. He is continuing to sell his first product — an eco-friendly compost bin. He takes branches and tree cuttings and weaves them into a container which is then used to compost all other garden waste.

And even if the green-fingered inventor does not become a millionaire from his products, he can always fall back on the bread and butter business of garden maintenance. “No matter what state the economy is in, the grass will always grow!” he laughed.

Contact: Lewis Oakley, GardenMaintain, 07841 590368 Web: www.gardenmaintain.co.uk