Fruit Trees - 5x5 or 3x3?

[worldly berry]

I've seen conflicting reports. I'm laying out my greenhouse and want to plant trees, plants and seeds. If I place plants first, I notice I need a 5x5 empty area to get a green square to plant a tree. I can plant the trees first, and then the plants - but I'm thinking the tress just won't grow.

Basically, to insure the trees grow - do I need to place them last in a spot still legal for them?

I know I can let the trees fully grow and then plant stuff within their 3x3 spot - did that on accident with an auto-seeder...

[jade dew]

If there is a building or border (farm or greenhouse) near to the tree, then it requires a 5x5 space. In all other cases, it should only require a 3x3

[night kelp]

Fruit plants can be placed right next to each other. You have to till to plant them. If it’s a sapling (fruit tree brown bag) you have to leave space between them but you don’t have to till the soil. Basically they need 3x3 around them and you don’t count the tile next to the edge of the greenhouse.