I have a suburban farm website that I made using wordpress. It is really just for fun but I want to build it with best practise in mind in case I ever want to do more with it. To this point I have been writing 'how to' and 'update' articles which are both fine as posts. I have also been writing keeping and growing guides as posts but really, this content is timeless. Before I get too far down the rabbit hole should I make this kind of content as pages? The fear is that eventually I could have hundreds of these pages, is that a problem?
There are 2 things here:
There is absolutely no issue in terms of ranking when it comes WP pages vs post. As long as you got rich content either should be fine.
Pages vs Post could come under your website planning and future consideration. For general understanding, pages are generally for website page and posts are for the blog.
Note: Also, it's good to have fewer pages with rich and good length content instead of having 100s of small pages.
Before I get too far down the rabbit hole should I make this kind of content as pages?
Doesn't really matter as long as you remain consistent with it. Personally, I would make this content into a custom post type and that would allow for custom taxonomies to better handle navigation and SEO issues, but this isn't necessary.
The fear is that eventually I could have hundreds of these pages, is that a problem?
Nah. Again, as long as you are consistent about which content container you use, there's no benefit nor penalty to using posts over pages.
Articles/posts with links to always reputable University Agriculture resources can't hurt. Try Google search [site:.edu filetype:pdf etc terms etc] for key resource docs and work from there to direct traffic/integrate with invites/orders. In addition, several market farmers/gardeners I've spoken with report earnings near or better from farm holiday/edu-tainment/activity/tourism events than actual field produce sales - which have advantage of dates/times and so always fresh upcoming content. With CMS platforms custom content forms and filters/list can make events calanders easy.