A shaded grassy walk, the perfume of perennials, the low buzz of bees – what more could one ask from a garden? Plenty, it turns out. The 30-odd artists in “Down the Garden Path: The Artist’s Garden After Modernism” investigate all manner of historical, ethical, aesthetic, and political issues relating to a subject many of us have taken for granted.

The exhibition’s works vary in tone from the didactic to the whimsical, and range geographically as well as thematically. Some pieces bring soil and living plants into the museum itself, but most refer to site-specific works elsewhere. The museum has also taken advantage of its location in Flushing Meadows by commissioning five pieces installed or performed in the park.

While many works are purely conceptual, others amount to practical, hands-on demonstrations. A video records how the civic-minded Brian Tolle and Diana Balmori used a modified pickup truck to perform low-impact (but high-spirited) cultivation of the grounds outside the museum, sowing the ground with great arcs of poppy seeds. Lonnie Graham’s practical generosity shows in the thriving vegetable garden he started with several Queens families; visitors can see it for themselves a few hundred yards from the museum’s entrance. One long gallery wall, covered with comments, photographs, and letters, documents how the Hamburg-based “Gallery for Landscape Art” is working with the residents of a South African village to alleviate their water shortage.

Elsewhere, a series of photographs from 1994 depicts gardening implements, gardeners, and plants with the deadpan frontality of mug shots. Wall text clarifies the cryptic message: The images document the creation of a garden “open to all people, all the time,” in the words of its creator Ingrid Pollard, an artist of Guyanese descent whose works are a response to Britain’s brutal colonial policies.

Other works are motivated primarily by aesthetics. The urban parks envisioned in a dozen drawings and models by Isamu Noguchi from the early 1960s feature elegantly arranged hillocks and curves. Most were never realized, but in 2004 a handsome garden designed by Mel Bochner and Michael Van Valkenburgh was; a video provides a blow-by-blow account of its construction at Carnegie Mellon University.

Paula Hayes’s terrariums of plants in hand-blown glass vessels (2004) are about the closest thing here to traditional, self-contained art objects. They have the preciousness of ship-in-a-bottle curios, but these triumphant bubbles of life also look as if they would survive ecological disaster in the larger world.

Nils Norman’s pedal-powered contraption (1999) provides welcome levity, combining solar panels, a photocopy machine, and a library – it’s a whimsical environmental school on wheels. Most light-hearted of all are the bicycle-drawn, flower-bedecked floats of Dave McKenzie and Anissa Mack, available to visitors who might like to conduct their own parade through Flushing Meadows.

One weakness of the show is that the catalog is essential for connecting its roaming themes. Besides fleshing out the artists’ philosophies, it provides a barebones history of the garden, tracing its evolution from a mythic refuge in ancient times, to an exclusive royal playground, a medieval cloister, and more recently a public setting for social excursions. Amid some doctrinaire prescriptions (for, say, bringing “the disenfranchised closer to ivory-towered institutions”) are compelling details: How, for instance, some Jewish families sheltered in public parks during air raids after the Nazis had barred them from bunkers.

If there’s a common impulse, it’s one of visionary exhortation. This makes you wish for some follow-up: Did the cultivation-by-pickup-truck of Flushing Meadows actually result in swirling arcs of poppies? Did the South African village project yield as much new water as documentation?

Walking back through the park to the no. 7 train, you’ll feel slightly better acquainted with the floral world, and a great deal more familiar with the viewpoints of contemporary artists – as if they were the real riot, unruly and preoccupied, taking root in fertile soil.

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As is suggested by the title of “LandEscapes,” an attractive show at Bruno Marina, the landscapes of the six New York-based women in the exhibit all represent escapes into dreamlike or unusual dimensions. Maggie Tobin and Anna Lise Jensen achieve otherworldly effects through manipulation of media. Painting on layered translucent sheets, Ms. Tobin imparts a mysterious, iridescent depth to images of bare tree branches. Ms. Jensen’s deliberately out-of-focus color prints conjure up bright and surprisingly specific impressions of the Danish countryside.

Sheila Kramer’s two small oil paintings depict nothing but sky, but suffuse it with a luminous layered depth. In a large C-print, photographer Christina Dixcy gives a spooky incandescence to a radar bowl nestled in a vast, mountainous desert.

A close look at Elise Kaufman’s ink-on-Mylar drawings of city buildings shows a lively, contradictory overlapping of different, simultaneous viewpoints. Kamilla Talbot’s incisive colors and strokes lend vivacious light and space to unassuming scenes. Who would have foreseen the poignancy of antennae against a sweeping harbor view?

“Garden Path” until October 9 (New York City Building, Flushing Meadows Corona Park, Queens, 718-592-9700).

“LandEscapes” until August 28 (372 Atlantic Avenue, Brooklyn, between Hoyt and Bond Streets, 718-254-0808). Prices: $800-$3,500.