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
No matter how many plants you want to water, you need a knife, a pin and a pair of pliers.
Step 2: Perforation
Step 3: Absorption
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
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.