On Thursday morning, and as usual, the gardens teemed with birds. But the master plan (the entire vision will take 20 years to realise and will cost about $25 million of which on Thursday Bob Baldwin pledged $5 million of federal shekels), is, in part, an attempt to address the way in which the gardens seldom teems with enough people. Garden visits may even be dwindling. On Thursday ABC radio reported an annual dwindle of 10,000 (but we have been unable to source or confirm this nice round figure).

This lack of mass popularity may bewilder those of us who think the gardens a wondrous place. But lots of us who have this crush on the gardens are likely to be of mature years, and to have an esoteric enthusiasm for our native flora not shared by the masses, by the Floriade-going classes. And flower-ogling does not have nearly enough charms for today's younger folk.

And so some of the imaginings of the master plan (the 20-year vision will take an estimated $25 million, of which Bob Baldwin on Thursday pledged a federal start-up $5 million) imagine ways in which the gardens might lure and engage the young. So for example there may be a Nature Play Terrace "attracting families and engaging children in educational and adventurous play". There may be a "high ropes course" in which energetic children and young adults can swing and gambol among the trees, like Tarzans and (for today a woman's place is everywhere) Janes. There is envisaged a New Wedding Garden to attract all of the sorts of people, most of them perhaps indifferent to our flora but enthusiastic about true love, who flock to weddings.

But as well as attractions for the young the master plan does envision some other major projects.

Perhaps the most glamorous vision is of a new conservatory, a kind of giant glasshouse, in which the gardens will at last be able to grow and display plants of war and balmy Australia that can never be grown outdoors in chilly Canberra. Artfully, the area beneath the great glass roof will be a sunken space and this will mean that even quite tall trees will be able to be grown there without the conservatory having to be enormously tall (and enormously expensive) crystal palace to make room for them.

The new conservatory will be close to a new visitors centre and cafe reached by a grand bridge that passes over the ferny, frondy splendour of the rainforest gully.

Most of the changes, gardens supremo Dr Judy West told us on Thursday, are to be changes of infrastructure that leave the plants alone. But she said that one of the fruits of calling in architects and landscape architects (the firm of Tonkin Zulaikha Greer has composed the plan) to think and dream was that their new eyes had noticed just how illogical some of the gardens' arrangements were. For example, she marvelled, they'd pointed out how labyrinthine the present pathways are, with there being "one spot where you have eight decisions to make" about which way you should go next.

She thought this wasn't very "user-friendly" but as she expressed this controversial opinion this Gardens-fond reporter realised, without having thought about it before, that these sorts of winding, mystery-destination tracks are one of the Gardens' attractions. Is it necessarily a bad thing to have eight choices of anything, including of where to ramble to in idyllic gardens? In The Road Not Taken, the best known of all of his wise and beautiful poems, Robert Frost embraces the challenge of a choice of just two routes, let alone a smorgasbord of eight. Dr West is promising us more "logical" paths at the gardens but some of us will miss the old, illogical ones, that perhaps took us past a secretive shrub (in glorious flower) not previously noticed, that brought us upon a basking snake, a sunbathing lizard, a shy bunyip.

The Gardens has, but has never yet developed, a bosky southern bushland precinct, and Peter Tonkin of Tonkin Zulaikha Greer rejoiced on Thursday about what a "very exciting opportunity" this place was. It is where he imagines the establishment of an "eco-tourism lodge" and, among the trees, the "high ropes course". The high ropes will he hopes be "something that attracts teenagers and young adults, which are a hard group to get involved in places like botanical gardens".

The excitingly-envisioned conservatory is part of Stage 1 of the vision, expected to be up and open by 2020 to commemorate the 50th anniversary of the opening of the Gardens. It will be a kind of not-too-hot hothouse,a pocket of the tropics. In fanciful chat with Gardens staff on Thursday it was suggested it will be, especially in winter when the world outside may be bitter, a lovely tropical shock for visitors.

Correction. Human frailty. In a misunderstanding the ACT wildflower called an "orchid" in a caption to a picture in Wednesday's column was not an orchid. It was, as several readers point out with whoops of triumph, the Early Nancy.