The island’s natural vegetation risks being wiped out by invasive species unless private landowners take the initiative, one of the island’s leading environmentalists has warned.

David Wingate, the former chief conservation officer, has put his decades of experience, including turning back the hands of time on the Nonsuch Island reserve, into a guide on managing non-native plant species as well as promoting endemic varieties.

Dr Wingate told The Royal Gazette: “If we leave nature to itself, absolutely no native flora will be left.

“Our only hope in restoring Bermuda’s native plants is in private gardens and nature reserves.

“Private gardens occupy well over half of Bermuda’s land area, so our aim is to encourage landowners to plant native species to preserve our natural heritage.”

The free guide, A Practical Guide to Garden Management in Bermuda, is available from today at the opening of the annual Agricultural Exhibit.

It will also be available from the Bermuda Aquarium, Museum and Zoo beginning on Monday — along with any businesses that wish to help Dr Wingate’s endeavour.

Lisa Greene, former collection officer for the Bermuda Natural History Museum, said the booklet was the distillation of years of Dr Wingate’s expertise, including expertise from the 2007 Millennium Seed Bank workshop in Bermuda, organised by Kew Gardens in London.

Martin Hamilton, Kew’s programme co-ordinator for the British Overseas Territories, told The Royal Gazette at the time that “the invasives are worse than any place I have ever visited”.

He added: “Bermuda’s natural open forest canopy has allowed for invasive species to take over the ecosystem.”

Scientists found swaths of the island covered by “monocultures of Brazilian pepper or Surinam cherry that create impenetrable thickets and basically shade out all of the native and endemic plants”.

Dr Wingate said: “The work really began through my development of Nonsuch Island as a living museum, and my learning about what the island’s pre-colonial flora and fauna were like.

“I learnt as much about Bermuda’s pre-colonial history as possible, and how it changed over the centuries since. That became my primary interest in life.”

Dr Wingate said he had written “very long and detailed articles” and published papers on Bermuda’s native species and the impact of invasive species.

Ms Greene reviewed the work and suggested a focus on “restoring nature and Bermuda’s heritage by planting trees and selecting natives”.

“If I were to be doing this myself, or the average property owner, how would you go about it?

“I turned to David and all his years of experience doing pretty much just that.”

In 2007, Dr Wingate took visiting scientists on tours of the island’s nature reserves — and decided in the aftermath that “with the best will in the world, Bermuda’s government would not be able to deal with the problems that invasives pose”.

He added: “We really need to put these tools into the hands of the Bermuda public.

“I really want the publication to get to property owners who have autonomy to make changes on their own land.”

Dr Wingate began putting together the guide after his retirement, assisted by interviews by Ms Greene.

She said: “It’s not just about natives and endemics. There are a number of what David terms as native compatible and that are not so aggressive, such as lantana and hibiscus.

“The question is, does this easily self-propagate? Is it aggressively self-seeding?”

The two examined how invasive species get spread and how easily they can be controlled.

Dr Wingate said: “The bottom line is the situation in Bermuda is very bad with regard to their impact on the native flora.

“You get woodland reserves that are overrun with non-native flora — things like the Chinese fan palm, allspice, Surinam cherry, that are so aggressive they out-compete everything.

“Native and endemic flora are well suited to the island’s growing conditions. They’re able to stand up to 90 per cent of the gales, salt spray and droughts.

“We do not want to stop people from planting exotics. They will be better off if they are protected by native plants.”

Ms Greene said there were “a lot of people who want to do this and just don’t know how to do it”.

The guide was put together over the past two years, as part of Dr Wingate’s broader project of committing his knowledge to paper.

It focuses on how to remove invasives and replant, all based on his experience, and taking pains not to duplicate information already published.

The Bermuda Zoological Society covered the cost of the booklet, which comes with cover paintings donated by Jill Raine, and text illustrations by Fae Sapsford.

Ms Greene said the next phase would be to get the booklet available online for download.

She added: “For those who want a deeper understanding of the problems affecting Bermuda’s flora, there is an appendix by David, which is an ecological explanation of the changes in Bermuda’s flora over time.

“We are hoping that property owners will be empowered by the guide — that it answers their questions, provides the information and impetus they need to make changes to the planting on their property.”

• Businesses looking to give out the booklet can reach Ms Greene at elgreenebda@icloud.com to request a delivery