The second part is spot on.
It's the first part which is not quite right.
You can touch the 'growing stuff' with your practice swing providing you don't damage it such that it improves your swing area. See the decision below.

13-2/22 Knocking Down Leaves with Practice Swing


Q. A player’s ball lies near a tree or bush. The player takes a practice swing near his ball and knocks down leaves in the area of his intended swing. Is this a breach of Rule 13-2?

A. The answer depends on whether the area of the intended swing is improved. In some cases, the knocking down of a number of leaves would not improve the area of the intended swing as the player still has to swing through a number of remaining leaves when making his stroke. In such circumstances, there would be no breach of the Rules. In other cases, the knocking down of one leaf might improve the area of the intended swing, in which case there would be a breach of Rule 13-2.
If a player has improved the area of his intended swing by knocking down a leaf or a number of leaves, he cannot avoid penalty under Rule 13-2 by subsequently changing the area of his swing when he actually makes the stroke.