One of the best ways to save water in the garden and help prevent weed growth is to use a nice thick layer of mulch. Some people also use black plastic which certainly works, but isn't the most environmentally friendly option.
  
Ecocover is a mulch mat produced mainly from waste paper removed directly from the landfill waste stream. According to the makers, it provides better weed suppression compared with black plastic during the effective life of the mat, conserves up to 80% of soil moisture, provides nutrients to the plant and is 100% biodegradable.

Ecocover can be used on the surface
or beneath other materials

Originally developed in New Zealand, Ecocover is available in the USA and now also in Australia.

The company has just started up operations in Australia at Coffs Harbour under a non-profit organisation called Coffs Challenge. Besides manufacturing this product from waste (which is great in itself), the Australian facility is also providing employment to 45 disabled workers who require ongoing support at the work site  - fantastic stuff. 

Coffs Challenge is a community-based organisation that assists people with a disability to achieve positive outcomes in their lives - increased independence, employment opportunities, and meaningful participation in the community.

Some other benefits of Ecocover include:

- promotes plant and seedling growth
- improves soil health and productivity
- stabilises soil temperature fluctuations.
- reduces soil erosion problems. 
- helps to reduce herbicide use.

Before you buy a bunch black plastic for your next garden project, take a trip out to EcoCover and check out the range of products. The Australian site can be viewed here.

Related:

Saving water in the garden
Composting tips
Worm farms and vermicomposting