פירוש על בראשית 1:12

ותוצא הארץ וגו AND THE EARTH BROUGHT FORTH etc. — Although the expression למינהו according to its kind, was not used when the various kinds of herbage were bidden to come forth, they heard that the trees were so commanded and they applied to themselves the argument à fortiore (ק"ו), as it is explained in an Aggadic passage in (Chullin 60a).

And the earth brought forth, etc.: Also in this verse, the author of the cantillation marks distanced the word "lemineihu" (of its species) from the words, "that has seed in it," and 'moved' it above; which is [as if] to say "And the earth brought forth trees of its species, and it makes fruit and its seed is also in it." And so [too] did he distance "of its species" from "that bears seed" and 'moved' it to [refer to] "grass" and to "herbs."

AND G-D SAW THAT IT WAS GOOD. This affirms the existence of the various kinds forever.
There was no special day assigned for this command for vegetation alone, since it is not a unique work. The earth, whether it brings forth anything or is salt land, is one.