system
A chat on subreddit /r/NoStupidQuestions
human
If I remember correctly from a school lesson, grass grows from the base, hence you can mow your lawn and the plants survives.
gpt
Both trees and grass are actually more complex than that, in that they grow in stages.
So there's the stretching stage, in which a new branch/stem/blade stretches out, then a hardening stage, and then we're ready for the next level to start stretching. But once the hardening has started, things are stuck in place. For some trees, this is each segment (internode) between leaf attachment points (nodes) stretching and hardening in sequence until the season ends, for others it means a whole bunch of tiny leaves spring forth from a bud and stretch out while they grow. Oak trees are funny in that they do the latter, but multiple times per season. I have a young oak that added 84cm last summer. I saw no growth until after May 17th (our constitution day), almost 50cm of growth by midsummer, then a few weeks of rest before it flushed again with another new branch which grew much slower.

So, to summarize: distance between branches doesn't change, but length of a branch does, until it hardens enough that it can support further branches.


Adding:
Growing oak from acorns is the most fun I've ever had with plants. Once that sucker appears, it grows both up and down by up to an inch per day in good conditions. So if you see some acorns that have just fallen from an oak, pick some up and put in some glass wool on top of a good amount of expanded clay (I would say a 2L soda bottle with the top cut off, so you can see the root stretching down). The glass wool is magic at holding moisture. Then wait 3 weeks before it sprouts, then in another three weeks you should have yourself a healthy little tree.