Despite its location, and being open only from March to October, the garden pulls in up to 30,000 visitors a year.
Recently appointed curator Richard Baines believes that the 10ha garden can do more to fulfill its potential. "We have a good garden, but need to use it more," he says. "We are trying to put in more to appeal to children. There should be something for everyone."
Primary-school children are tempted with Harry Potter-themed events and Walking with Dinosaurs tours, while older pupils are asked to consider what life was like as an intrepid plant hunter.
"We are getting a lot more secondary schools," he says. "Word has got about, but you have to work hard at it."
Art installations have been included for the first time this summer. A refurbished visitor centre features a 40' LCD screen and microscopes. And MP3 players, soon to replace tape-based systems, will allow self-guided tours. Children's tours are recorded using children's voices.
"It should be fun, it should tell a story and bring the collection to life," Baines says. "A garden should let people feel adventurous. They shouldn't have to worry about stepping on the grass."
Lest it be thought that Baines is dumbing down the garden to broaden its appeal, he is also developing the garden's national collections, which appeal to gardening clubs and other specialists. Logan has already applied for National Council for the Conservation of Plants & Gardens (NCCPG) status for Gunnera, Griselinia and Leptospermum. "We already have the collections, it's just getting the recognition," he says.
Palms are a specialism of the garden and a recent feature on BBC Scotland's Beechgrove Garden from Logan emphasised the range of palms available to domestic gardeners, including Rhapidophyllum hystrix, the endangered but cold-hardy needle palm.
Half of all plants are from the southern hemisphere, with particular focus on New Zealand, Tasmania, Chile and the islands of the south Atlantic. Nearly half were also collected from the wild.
Plants such as the tree fern Dixonia thrive in the 1m-plus annual rainfall and even form "carpets of weeds", Baines says. The less familiar dwarf tree fern Cyathea dregei is the first to have been grown outdoors in the UK, but it is "really tricky", he adds.
Another first is Blechnum cycadifolium, a tree fern from the Juan Fernandez Islands, which will eventually have a trunk 1m in diameter. "Remote islands tend to have a lot of endemics," says Baines. "I see our role here as being to distribute them, to inform people about them and to show them off."
He plans to open up an underused area over the next 10 years as an arboretum focusing on Mexican trees such as Magnolia stellata, threatened in the wild. "I'm able to instigate these things and get the support from Edinburgh in the form of additional staff or plants," he adds.
Logan also boasts over 50 species of Eucalyptus, many collected from the wild in Tasmania by previous curator Barry Unwin who headed the garden for 33 years and "still gives advice", says Baines.
Next month, Baines will embark on his first overseas plant hunt, seeking material for the garden in the uplands of northern Chile. "You learn a lot more about them seeing them in the wild," he explains. However, with Phytophthora recently arrived in Scotland, Baines is not bringing in any live plant material from other gardens.
A hundred years ago, the garden hosted curling matches on the frozen ponds. "It shows how the climate is changing and lets us push the boundaries," he says. Although frosts are now rare, a -10 degsC cold snap in 1996 was "devastating". He adds: "We have things like an avenue of cabbage palms framing the lily pond, which we can grow if the climate stays mild, but one severe winter could knock them out."
Baines' team has experimented with a variety of methods to protect plants, from fleece to bracken.
Maintaining a staff of eight in such a remote location might pose problems for recruitment, but Baines says: "The garden has a good reputation, so you get good applicants."
Work continues year-round, he adds. "There is more to do in winter - things like dredging the lily pond. If you get things under control in winter, then summer is easy."
Students at RBGE also regularly help out on larger jobs, while students from other countries spend time working and studying in the garden.
The garden is clearly a labour of love for Baines, whose passion for plants spills over into home life. He admits: "We have a 2ha garden with around 230 species of Rhododendron."
1984-86 Trainee gardener, Threave
1987 Scholarship to Longwood, US
1988-91 Royal Botanic Gardens, Kew
1992-96 Glasgow City Council Parks Department
1996-2006 Head of horticulture, Barony College
2007 to date Curator, Logan Botanic Garden, Scotland