Since I'm not particularly invested in this SE site, I'm just putting this out there for you lot (the local community) to discuss, but I don't think this is a very good tag, because it feels very much like a meta-tag to me.
Specifically, the identifying points of a meta tag are:
- If the tag can’t work as the only tag on a question, it’s probably a meta-tag. Every tag you use should be able to work, more or less, as the only tag on a question. Meta-tags, like [beginner], [subjective], and [best-practices], are useless by themselves — they tell you nothing at all about the content of the question.
Use this tag for general questions about growing vegetables or for questions about a particular vegetable in combination with the specific tag for that vegetable.
Which makes it entirely clear that this tag shouldn't be used on it's own.
If a tag cannot be used on its own, is it useful?
Using my question as an example, it was already tagged peppers, so what value does vegetables add?
If a question was just tagged vegetables, what would that question be about?
Really, is this much better than a theoretical gardening tag?