Dave Bonta's short poem puts us in a field, probably, where "we" are lying or standing so deep in the grass that an onlooker might take us for horses. The odd phrase "bull weather" suggests heavy, restless, perhaps hot conditions, and the title's "leaves of gas" hints at something airy and strange, as if the grass itself were made of vapor. The images don't fully add up, and that seems part of the point.
The speaker sounds relaxed and a little amused. Being "deep as drunken scholars" in the grass mixes learning with loose, easy intoxication: thoughtful people who have stopped trying to be serious. The last lines imagine a conversation that "lives" in the grass, one big enough for everyone. It feels as though the field itself is talking, or at least holding all the talk that matters.
The mood is dreamy, playful and quietly content. Nothing happens, and that is the pleasure. The poem invites you to drop into the grass, lose your human outline, and listen.