When you visit the new Native Plant Garden at the New York Botanical Garden in the Bronx — and it should be a matter of when, not if — you will not see what I saw last week, and perhaps not even the garden that will attract visitors over the next two event-filled weekends. Gardens are like rivers. Not only can’t you step into the same garden twice, but their evolution is so fluid, you also can’t even step into the same garden once.

So what you might see at the new garden’s opening on Saturday, with its nearly 100,000 plantings of some 400 species native to the Northeast, spread over a freshly landscaped 3.5 acres, is really a plan just beginning to blossom. It is now a gently ornamented structure, a still-skeletal display awaiting imminent transformation. We look at what is but see what is about to be. Philosophers would say that a museum exhibition with its static displays of venerable objects is about “being”; here the focus is on “becoming.”

That means that the plantings will eventually start living up to their uncanny names: the plugs of white wand beardtongue and rattlesnake master will fill in on the meadow; the wild columbines with their red-and-yellow flowers will be more than a twinkle in the gardener’s eye; and heartleaf foamflowers will emerge with eccentric finery. By now, the nautilus-shell curls of nascent Dixie wood ferns and cinnamon ferns that I saw will surely be unfurled. Will Virginia bluebells have peaked?

This idea of process and transformation — of a garden as a web of interacting flora changing over time — is found here not only because the garden is new: That idea is also one of its preoccupations. It is an aspect of the cultivation style that the Botanical Garden has been exploring in its major reconstructions of recent years, in the Azalea Garden and the restoration of the adjacent Thain Family Forest. That style reflects an important change in our understanding of nature and gardens.