You will not be given access to the Tree Groves until your farm reaches Level 10, and once it does the Groves (there is an FCV Construction Project version that costs $10Kc and requires requested materials and neighbor labor to build, and a pre-built version that costs $22b but lays the trees out in a straight line rather than as a block of four trees).
The Grove/Orchard that you build using the Grove Construction Project and FCV holds four trees. In addition to allowing you to save a small amount of space (each grove takes up the room of a half-unit less than four trees placed in a block would take up, so once you have multiple Groves in place you actually are saving space), they also have other special effects:
- Each Grove holds four Trees.
- When all four are the same type they deliver extra fruit per harvest.
- Trees placed in a Grove require less water to tend them.
- Growth Timers for Groves are averaged between the timers for the Trees that are placed in it.
Tree Groves offer the ability to have more trees in less space.
To construct the FCV-based Grove Projects you will require the following resources that are requested from your friends:
- x8 Buckets of Paint (Feed Request)
- x8 Bags of Grove Soil (Direct Request)
- x8 Wood Planks (Direct Request)
Chances are you already have a supply of Wood Planks due to their being a popular selection for the daily Free Gift you can give to your neighbors, plus they tend to appear in the Feed a lot too.
The factor that is causing the new Groves to influence Tree deployment is the fact that they only hold four trees (in the original Farmville they held considerably more).
It is possible that at some point in the future they may introduce larger Groves but this is doubtful; the reason that the Groves only hold four trees is likely because the farms in FarmVille 2 follow a much smaller and more intimate set of dimensions...
So as you proceed and begin deployment of your Tree resources you may want to bear all of this in mind and restrict your purchases to groups of four, since mixing tree types in your future Groves will have a detrimental effect.