An interesting application. I used to professionally test applications in my technical writing job, so I ran yours without looking at any docs, as per our testing standards. My experience is that most software users (in the US, at least) don't read any documentation when they get a new piece of software, nor do they WANT to read any docs. (an aside: I was once told that I had "too many words" in a five-page online document that consisted mostly of screen captures with, IIRC, 100 words. The page count was too high...).
For what it's worth, here are my findings (I did not create an account):
Pest Identification
This is an excellent feature which I liked very much seeing, but I fear that few users will actually do it. We occasionally get posts here that say something like "Saw holes in leaves, nuked garden with a ton of pesticides, holes still there. Why?" No desire to ID a pest, just throw chemicals at the garden. A link to a pest ID site (not run by a chemical company) would be an excellent addition, if possible. Or did I miss this?
Change "bug" to "insect", as most of the pests in a garden are in fact insects, not bugs. Don't forget slugs as a pest, too.
I don't use social media, so if you're relying on it for account entry or connectivity with other users then you've already excluded me from using the app. If I don't use the app, I cannot recommend it (FWIW, I now work in the horticulture trade and often recommend tools to my clients).
Planting Calendar Section
Based on Gröningen as the default location, I'm guessing English is your second language, in which case I strongly commend you for the mostly excellent text in this app. As I would expect, there are some areas of text that contain awkward phrasing, though, and I suggest that you have your site proofread by someone who is a native English speaker, if you're planning on an English-only application. Two examples of these are below:
- On the Creating a Plant Calendar page: "On the right you can find a set of filter options that you can use to customize a planting calendar or to filter the results returned when quering the plant database." Should be querying the plant database".
- In the following sentence, "metric and imperial measure system" is non-idiomatic; I would change it to "metric and imperial measurement systems" (the "and" requires a plural here).
You don't seem to have the ability to create a planting calendar based on starting seeds indoors. I only start my peppers, tomatoes, eggplants, onions, cucumber, and melons indoors, not outdoors (if I started them outdoors I'd never get a crop in my area). To me, this lack is a dealbreaker and makes this aspect of the app useless.
You don't seem to have the ability to add plants purchased from local nurseries or farmer's markets. Rather than seed-starting time, you'd have to track "earliest planting time" based on last frost day, I suppose, or maybe something like "planting time for purchased plants". This could be useful if also tracking "indoor seed planting time" as mentioned above. Perhaps I missed something in the app?
Menu
The leftmost icon in the Menu sidebar does not have a "hover" instruction, nor does it actually work.
When a user clicks on the Switch Calendar icon and selects Database, the focus should go directly to the Database entry field. On my screen, that field is off the bottom of the screen and the icon Database selection looks like it's broken because you can't see it or the Filter options. I'm using the Opera browser, with regular (as opposed to HDR or gaming) graphics.
Database
I see that you don't need a scroll bar on the item selection lists, but it's not obvious that having focus on the open combobox (?) control allows you to use the mouse's wheel to view the rest of the list. I agree that this type of control should have a scrollbar.
What the heck is "Pea marrowfat?" Similarly, US users probably won't know that "aubergine" means "eggplant". Common names are going to be an issue, I think. I suspect that coming up with a type of "alternative name" option based on location could be a solution, but it would certainly cost time to add it to the database, queries, and pages.
You have a factual error on the Yellow Alpine Strawberry data. It's listed as being hardy to -9.4F and US Zone 5A. -9F is actually US zone 6, not zone 5. Perhaps this only an artifact from test data?
Journal Entries
Are all Journal entries public (in other words, will all entries appear in the "Latest Journal Entries" section)? If so, then this could be an issue for some users. See below for another comment about this feature.
As a user, I would like to create a permanent filter on "Latest Journal Entries" so that I only see those in my State/Province, my growing zone (US/Canada) or minimum winter temperatures (and possibly maximum summer temperatures). I don't want to see what someone two zones warmer than me is doing, as it's more than likely irrelevant to me.
I would also like to see Journal Entries (not necessarily recent) by topic: Seeding Issues, Pests, Weather, etc. Or is the intent of the Forum?
Other
I like the idea behind the Shadowcaster feature, but not sure if most users will be able to equate it to "full sun"/"part sun", which is really all the info that vegetable gardeners need.
I'm not sure what the purpose of the "Soil Grids" feature is.
The Forum doesn't work because you've been banned from Reddit.
One last thing, and this is quite minor - no tech writer or developer ever refers to a software issue as a "bug" in public-facing documentation or screens (I'm referring to your News page); we always use "issue" instead. Supposedly, users don't trust an app if they see that it has known bugs. Not sure how relevant this is in today's world, though.
Hope these comments and suggestions help!