He that bites on every weed must needs light on poison.

The image is of someone tasting plants without checking them first. Even if many prove harmless, trying them all makes an encounter with poison inevitable.

More broadly, the proverb warns that indiscriminate experimentation exposes a person to avoidable danger. It favors judgment and restraint over giving every option a chance.

Use it to caution someone who repeatedly takes chances without weighing the risks. It is most apt when the concern is a pattern of indiscriminate choices, rather than a single unfortunate decision.