You know the type. There's a tomato tour, whether you asked for one or not. There are compost temperature updates delivered like weather reports. He owns a rain gauge and has opinions about it. The lawn has a maintenance schedule that would embarrass some businesses. Gifting him is easy in theory and a minefield in practice, because he already owns the obvious stuff and has strong feelings about the rest.
The trick is buying for the specific version of him: the guy who wants tools that last decades, gadgets that give him real numbers instead of vibes, and gear that makes the science part of the hobby more legible. He doesn't need another novelty seed packet or a mug that says "garden fairy." He needs the thing he keeps almost buying for himself and then talking himself out of.
Below is a spread across his sub-obsessions and across price points, from a ten-dollar soil probe to a full backyard weather station. Every pick answers one question: why this, for him, specifically.