Each tour, by specialists in their field or specially trained guides, has been planned to ensure people get the most out of the garden.
Nick Wray, Curator of the Botanic Garden, said: "We are very excited about our new themed tours that have been developed for 2011.
"No prior booking is required, people can pay on the day and enjoy a stimulating and enjoyable time feasting on the beautiful plants at the Botanic Garden."
The tours, costing £4.50 per person, children under-16 free, are open to everyone and the glasshouses will provide an alternative venue in the event of bad weather.
The themed tours taking place during June and July include:
Folklore of western herbs - Thursday 9 June, 6.30 to 8 pm
This tour with Ann Freeman will look at the folklore surrounding many of the common and not so common herbal plants that are to be found in the countryside and gardens.
Sex in plants: how plants reproduce - Monday 20 June, 6.30 to 8 pm
Professor Simon Hiscock, Director of the Botanic Garden, will focus on the process of pollination and fertilisation and will introduce both the problems and advantages of out breeding and inbreeding and how plants are able to switch between the two.
Bioengineering: plant solutions to engineering and manufacturing problems - Monday 27 June, 6.30 to 8 pm
This tour by Dr Heather Whitney in the School of Biological Sciences will focus on some of the established examples of where plants have been used as inspiration for new ideas and will highlight research that is currently being undertaken into new and exciting ways in which we look at the world's plants.
Pollination: new ways of exploring how plants attract pollinators - Wednesday 29 June, 6.30 to 8 pm
Dr Heather Whitney in the School of Biological Sciences will discuss new research being carried out that will lead to a better understanding of the many diverse and fascinating relationships between plant and pollinator.
People, plants, places: traditional herbal use from around the world - Thursday 7 July, 6.30 to 8 pm
Ann Freeman will talk about the gardens extensive herb collection and will highlight some of the most important medicinal plants to be used around the world, examples of which grow in the Botanic Garden.
Chinese Herb Garden explained - Saturday 9 July, 10.30 am to 12 noon
Dr Tony Harrison from the Register of Chinese Herbal Medicine, will give an opportunity for people to begin to understand the ancient philosophy behind Chinese herbal medicine whilst seeing first hand many of the plants used.
The evolution of plants and animals explained - Wednesday 13 July, 6.30 to 8 pm
In this tour Ed Drewitt, Bristol Dinosaur Education Officer in the School of Earth Sciences, will give an overview of animal evolution while Dr David Speller will introduce the key stages of plant evolution.
Plants and their adaptation to fire - Tuesday 19 July, 6.30 to 8 pm
Nick Wray will explain the background to plants co-evolution with fire, how they have adapted and the surprising benefits from living in a habitat that is periodically destroyed.
For more details on the above tours and other educational activities at the Botanic Garden visit http://www.bristol.ac.uk/Depts/BotanicGardens/ or telephone 0117 331 4906.