Questions about tools are certainly welcome; we have a couple of (albeit low-use) general-purpose tags for them: tools and tool-maintenance.
We also have special purpose tags for a few types of tools: string-trimmer, lawn-mower, chainsaw.
Often, the questions aren't tagged with the name of the tool, but with the action you'd use it for. So we have pruning ...
At the risk of making the "on-topic" list too long to be easily digestible, I'd split that bullet point into two: one for identification and one for diagnosis/treatment of problems.
As you've noted, we welcome lots of plant identification questions, though some types I don't see as being completely appropriate — seaweed or lichen, for example — ...
Theoretically you can germinate fungal spores and bacteria as well as seeds from plants. If you only go by the definition then germination includes everything seed starting implies and a little more.
The only thing seed starting has going for it is that it is more recognizable to the user base as I believe there are less users who use germination as their ...
During the week that the challenge ran, we received 6 questions tagged terminology:
What is apical dominance?
What's the difference between annual, biennial, and perennial plants?
What's the difference between corms, bulbs, and tubers?
What is the term for this pruning technique that causes stubby, clublike branches?
How can I identify the “type” of a rose ...
During the week that the challenge ran, we received 7 questions tagged seed-saving
How do you collect and keep cucumber seeds for planting the next year?
Can I save the seeds of Maiden Grass?
How do I save lilac seeds?
Can I save the berries from a Big Blue Liriope (Liriope muscari) and plant them next spring?
How can I save seeds from strawberries?
Can I ...
They seem to be mentioned widely enough to warrant a tag; the proper name for them seems to be string trimmer, with strimmer being one of the synonyms, so I'll create them and add the tag to your post (expect a couple of edits as I do it). Update: done!
I'll also go through and retag some older questions that could use the new tag.