The free event, held on October 18, will have a gardening seminar and exhibitions from Sydney Water and one about compost and worm farms.

Baulkham Hills Council senior sustainability officer Evie Roberts will be talking about the features of a waterwise garden soil types, plant selection, how to water efficiently and environmentally friendly concepts.

She said waterwise gardening could be done by people starting their gardens from scratch and those with existing ``thirsty'' gardens.

``It's so important for us to conserve our precious water resources,'' Ms Roberts said.

``Plants also play an important role in reducing the impact of climate change by absorbing carbon dioxide.

``People can make simple changes like planting native plants, which have adapted to the dry climate we have in Australia, and installing a water tank and use rain water in the garden,'' Ms Roberts said.

``Mulching and composting are essential to stop water evaporating and the soil drying out.

``It also improves the soil water-holding capacity.''

The waterwise gardening seminar is free but bookings are essential.

The Vinegar Hill Memorial Library is at 29 Main Street, Rouse Hill Town Centre.

Bookings: 88895200.