I'm no gardener, more the scorched earth type, but from your description what you want to do seems fairly straightforward, and the kind of thing that general-purpose spreadsheets like Excel do pretty well. There are probably templates available - a quick search turned up
this - and you can then customise it however you like. Having 1000s of plants would be no problem, and you can search, sort, analyse, make tables and graphs, etc etc. Presuming you already have Excel or a similar app, it's free (apart from the muttering and cursing time you spend setting it up).