In Matt Mattus’s garden and greenhouse, analysis and artistry are as closely intertwined as the annual vines that represent just one of his many botanical passions.

On one hand, Mr. Mattus has a trial gardener’s mindset — or, at least, that of a disciplined curator, ever looking to weed out the vines that don’t measure up and showcasing only the finest. He doesn’t merely dabble in a genus; he dives in headfirst.

Not content to sample a sweet pea or two, he once ordered dozens of Lathyrus species and varieties from an English seed catalog so he could grow them side by side, compelled to make his own assessment — and maybe discover an overlooked standout.

But Mr. Mattus was also a graphic artist and toy designer at Hasbro for many years, so he brings an artist’s sensibility to his gardening, constantly conceiving garden scenes.

He conducts his experiments in a two-acre garden surrounding the 1906 house in Worcester, Mass., where he was raised, and where he and his partner, Joe Philip, have lived for almost 25 years. It was once Mr. Mattus’s grandfather’s house, and his father was born there; both previous generations gardened there, too.

These days, there is always something being collected for study, including an assortment of fancy-leaf begonias (“Can anyone really have too many?”) and at least as many lilies. (“How many are enough? I really don’t know yet,” Mr. Mattus mused, acknowledging that the lilies’ fragrance is “nearly too strong” indoors if he isn’t judicious about his bouquet making.)

One recent growing season, he conducted a trial of about a dozen flowering-tobacco varieties (Nicotiana). Yes, the catalog descriptions note distinctions, he allowed, but “I like to see them all together.”

Seeing — and taking notes — is believing. And it’s how garden and gardener grow.