W. S. Merwin and Adam Fitzgerald are such dramatically different poets that reading their latest books in tandem can induce a feeling of vertigo. Imagine a playlist that squeezed together the music of Nick Drake and Lady Gaga, or think of a loaf of wild-yeast sourdough bread all rainbow-spangled with Pop Rocks. But both books have essential things to say about the movements of memory and loss — about what our minds try to hold on to, and why.

Mr. Merwin, 88, is a former poet laureate who came of age during the golden days of radio. In “Garden Time” he delivers a late-period distillation of the type of lyrics he has been polishing for decades. Unpunctuated, yoked to gentle rhythms, and all the more radiant because of their restrained vocabulary, these are poems that bring the reader back to phrases like “morning light” and “clouds over the mountaintops,” “sun-filled leaves drifting among the butterflies” and “let’s stay home together my love.”

Image W.S. Merwin Credit... Matt Valentine

Scholars sometimes caution us not to go looking to poetry as a source of relaxation — the stuff’s not Xanax, after all. But there’s no denying that much of Mr. Merwin’s work has the calming quality of a murmuring stream. Here are the opening lines of “One Sonnet of Summer”:

Summer has come to the trees reaching up for it

it has come in daylight without a sound

it arrived when the trees were dark in sleep

they dreamed it and woke knowing it was there

Now consider those lines in contrast to the closing stanza of “Prospero’s Books,” a standout in Mr. Fitzgerald’s book “George Washington”:

Goodbye, Blockbuster Video! Farewell to the Monopoly Man.

Read up on UFOs. Marvel at their beginnings: an interracial

Vermont couple sees aliens. We vacationed with JVC Camcorder

at CVS Euphrates. Delta Burke left Designing Women in 1991.

If Mr. Merwin’s work feels like part of some timeless continuum, a river that stretches all the way back to Han Shan and Li Po, Mr. Fitzgerald’s poems appear to arrive at that bend in the waterway where the currents are clogged with pop debris. In “Garden Time” (as the title implies), you might find a refuge from all the clutter and clang of contemporary life. But in “George Washington” (whose title gives you an early hint, á la “Hamilton,” that it will apply a fresh coat of paint to what we think of as American history), you’re right in the middle of the overload, channel-surfing from “Teenage Mutant Ninja Turtles” to “Thomas the Tank Engine” to LL Cool J to Bill Nye the Science Guy. (All of those references come from one poem, by the way — “The Remake.”)