Tree saplings
A sapling is a special seed that first has to grow before it shows you which tree it turned into. While it ripens you see it as a Growing tree, and once it finishes growing it turns into a Mysterious tree that you open to find out the exact reward. Judging by the descriptions there are dozens of different trees - some permanently raise the output of a specific production on the main farm, others only hand out a limited number of batches of some resource or themed crates.
I treat a sapling as a free bonus on top, not as something you can plan around, because both the resulting tree and its reward are random. It pays to plant every single one you get your hands on - it costs you nothing and even the weakest result gives you at least a small plus.
A sapling grows first and then waits for you to open it
Once planted, a sapling (listed in the overview as a Growing tree) has to develop first - until the growing time is up, you get nothing out of it. As soon as it is fully grown it turns into a Mysterious tree, and that is your cue to come back and examine it. When you open it, the game shows you which particular species you have grown and what bonus it carries.
Until then you know absolutely nothing - a sapling can turn into dozens of different trees with completely different effects, so I treat the result as a surprise rather than a planned investment.
A tree either permanently raises farm output or gives a limited number of resource batches
From the descriptions of the individual trees you can tell that they fall into two fundamentally different groups.
- A permanent percentage bonus to production on the main farm - this kind of tree raises the output of a specific category for as long as you keep it planted. I have come across bonuses to field output (Winter veil spirit, Giant pinecone), orchards (Lantern tree), factories (Douglas fir) and further on to milk production (Baobab tree), eggs (Socotra bottle tree) or nutrient leaves (Ginkgo tree, Sweet cherry).
- A limited number of automatic production charges - the tree produces a specific resource or item a few times on its own and then its effect is over. This group includes for example diamonds, catalysts (Nectarine tree, Crystal tree), seaweed resources, golden apples (Ruby tree, Snow-covered fir) or various tokens and crates (Wisteria tree, Socotra dragon tree, Hydrangea tree).
Which type and which specific resource you end up with is not something you can influence - it only shows once you open the Mysterious tree.
Diamonds and certificates are what I consider the most valuable reward
Among the trees with a limited number of charges, I find the most useful ones to be those that pour out universal resources you can use at any time - diamonds come from the Ice-bound willow or the Spirit tree, for instance. I put the Glacier pine and the Rainbow tree in the same bracket, as they produce certificates.
Trees producing seaweed resources, ordinary and precious catalysts or golden and silver apples are fine too, but I rank them a level below - those are resources you can also get through normal play.
Seasonal trees tie their reward to whatever event is running
Quite a few of the trees on offer have a clearly seasonal theme. From the Halloween collection I have tried out Slumbering Chaos (raises cherry production), the Night weaver (raises apple production) and the Lurking in the shadows tree (pours out championship coins). There are spring versions too, which instead of a universal resource give you themed crates in various colors - orange, purple or green - or tokens.
The effect of a tree like that mainly makes sense while the matching event is running and you have somewhere to spend the crates or tokens. Outside the season the tree still does its job (it gives a few charges of a resource), but that resource on its own is not much use without an active event.
