Take the long trees on the beams of my own house as an example. This is not a very mysterious thing. Mainly there are some poplars near me. These poplars have a lot of catkins every spring, and the catkins will be blown to my roof by the wind. If it encounters dew-like light rain again, it will probably meet its growth conditions, so it will sprout and take root there and plant it on the beams. This is a very simple natural phenomenon. Don't think it is too mysterious, and we haven't thought about what this tree stands for.
From the materialistic point of view, this does not involve the issue of geomantic omen. The so-called geomantic omen is just a kind of science produced by the combination of people's experience and hanging. It seems mysterious, but in fact it's just a profit-making under the guise of I ching gossip. The routine is exactly the same. I'll tell you all kinds of bad things first, then I'll tell you how to crack them, and then you'll pay the money.
Let's not talk about it from the perspective of feng shui. Just see if this tree has any influence on your house and your health. For example, if you leave it alone and let it grow on your house at will, it is likely that the root of this tree will grow longer and longer, and it will catch some water, which will make your roof very wet, which is not good for your health. Secondly, the growth of tree roots will also destroy the structure of houses and attract microorganisms, mosquitoes, mice and ants.
To sum up, a tree growing on the roof is not a matter of good or bad feng shui at all. It should mainly look at the impact on the house and health.