How to Save Water in Gardens and Small-holdings: the Scrooge Bottle.

The world is warming. Resources are dwindling. Clean water is in short supply. Recycling is ever more important.

Inspired by a trip to the Eden Project in Cornwall, this is a neat trick to save water in your vegetable garden, especially plants growing in pots and troughs, which dry out more quickly. You can get specially-made ceramic widgets, but this is my version made from recycled materials.

I call it the Scrooge Bottle.

Step 1: Materials and Tools

For each plant or pot you want to water, you need a bottle, and something absorbent to fill it with, such as cotton wool, old socks or the off-cuts from your jeans.

No matter how many plants you want to water, you need a knife, a pin and a pair of pliers.

Step 2: Perforation

The water needs to get out of the sides your bottle, but the bottle isn't porous. Hold the pin firmly in the pliers, and have at the bottle. Please, try not to perforate your hand.

Step 3: Absorption

Now the bottle is riddled with holes, the water could pour out instead of just oozing slowly. The bottle needs something to slow down the water's exit. That's what the absorbent stuff is for.

You could use the knife to shred the fabric so that you can get it through the neck of the bottle, or you could cut the bottle in half and stuff the fabric in easily. When the bottle is stuffed, wedge it back together. You may find it easier to wedge the halves back together if you put a small cut in each half of the bottle so that you can scrunch them up slightly to fit together.

Step 4: Using the Bottle

The bottle's function is to get the water close to the roots of the plant and not waste it in the rest of the soil or to the atmosphere. The best way to do this is to plant the bottle close to the young plant, such as when you plant your seedlings out, with just the top of the bottle sticking out of the ground.

You water the plant by pouring water into the bottle. You can use a funnel or a watering can with a narrow spout. If you live somewhere particularly dry or hot, you can save the lid and replace it between waterings to stop evaporation.

As the plant grows, its root system will grow around the bottle, all the better to absorb the water, plus any nutrients you add. This may reduce the roots' ability to support the plant (because they're all bunched up around the bottle instead of spread out to catch "wild" water), so taller plants may need supporting somehow, possibly with canes or netting.

If your plant has a limited lifespan, the bottle can be dug up and used again, but you may want to wash or replace the fabric inside the bottle to prevent passing any infection from old to new plantings.