The Manchester Guardian has an excellent article on the opening of the park, with a detailed account of the plantings by Dutch horticulturalist Piet Oudolf, and a comparison with similar projects elsewhere. I am impressed. Current horticultural thinking is all about "what wants to grow there".
Forty per cent of the species Oudolf put on the High Line were already there, dropped by birds and blown by the winds on to the railbed during its derelict years. Sustainable may be an overused adjective, but Oudolf embraces the notion, in that what was put there by nature was, by definition, sustained.
It reminds me of the agrarian writings of Masanobu Fukuoka, and reflects my own attitude about the ecology of urban yards.