When you’re buying trees to plant on National Tree Day, Sunday 1 August, it’s essential to ask some questions, says senior lecturer in the School of Agricultural and Wine Sciences Dr Geoffrey Burrows. “When buying native plants, it’s important that seed used in propagation comes from the local area,” Dr Burrows says. “For example, the Yellow Box eucalypt occurs naturally from Queensland to Victoria, but if you collect seed from somewhere other than your region, it means you are introducing genes that wouldn’t normally find their way to that place. You’re actually genetically polluting the local landscape.” Dr Burrows suggests shopping at a nursery that specialises in native plants where they are more likely to gather seed from the local surroundings. “You just need to ask if the seed is local before you buy the plant - that way we can naturally increase native biodiversity within the local area on National Tree Day.”