Residents can tap in horticulture teasers and be emailed or phoned back with tips from the green team at the local authority's Stanmer Nursery.
The website gives details of the city's 98 parks and open spaces such as Kipling Gardens in Rottingdean, 6,000ha of countryside and 45 playgrounds. Residents can book sports pitches and find out about allotments or volunteering.
It has "welcome" videos from nursery team leader Sarah Carlisle and friends groups, while rangers highlight their favourite features. The parks team also uses Facebook and Twitter so people can contact them directly.
Councillor Pete West said the website would encourage more people to get involved. "The new-look pages will make it easier to find out about our green spaces and enjoy them," he added.