Recently, they've added some sort of blackout feature to hide plants your friends have that you haven't discovered yet. I guess they want to keep up the mystery, but I feel they're hurting the game overall for no real benefit. Discovering new plants is really the only thing driving players forward in the game, and to do that they need to guess all the combinations of plants they can hybridize. If your friends are ahead of you in the game they will have found plants you have not yet found, so you can scout out their garden to see what they're doing and get some clues to what you should try next.
So you head over to a friend's garden and take a look a their plants. If you've found a particular plant already, the game will tell you the name when you see it in a friend's garden. Like this:
If you haven't discovered the plant yet for yourself, you get the old "???" of mystery, as seen in the next picture.
But now they have added this new blackout feature and made it much harder to scout out your friends' plants. Now, if your friend has a plant you haven't yet discovered you get this:
Very mysterious, sure, and while you can see the outline, which does contain some information, you can't see the colors and other details. The colors are especially important because many plants are color combinations of others. Red and yellow begonias make orange begonias, for example. If you can't see what color their new begonia is, you can't guess what colors of begonias were hybridized to make it - you won't be clued in to what colors to focus on. Green begonias are a great example of this, because crossing the blue and yellows isn't intuitive because the blues are advanced and have a very long growing time, while the yellows are very slow. (In fact, I'm only predicting that cross will work because I saw them in my friend's garden, and haven't found them myself yet.) They've taken away one of the only clues you could find when you're stuck on trying to figure out what to try and hybridize next.
This is an additional issue for the game, because learning something about plants you don't have is the only reason you have for visiting your friends at all. Taking that away is very bad for a Facebook game, as they thrive on friend-friend interactions.
Games should have mystery, but they need the right kind of mystery used in the right way. Don't hide information from a player unless you're sure you need to. Think carefully about whether using that information would add fun to the game or take it away? The almanac having ?s instead of showing you all the combinations you need to find is a good thing to hide. The game is more fun if you don't know that ahead of time. Hiding what your friends have found is weird, first of all - if I went to my friend's garden how would their plants be invisible to me? But I think it also makes the game less fun because when you can see the colors of the plants you can guess what makes them - and that's fun.
On a slight tangent, you could just call your friend and ask them for all the combinations they found... but most people don't. It's interesting to think about why they don't.