you likely using obsolete anarchy mods. The current one is Tree Control.

all others are obsolete : EML, tree anarchy, prop & tree anarchy... all obsolete.

citizen instances means the amount of citizen visually simulated on the street moving around. Of course your city size can goes way above that, but due to software age & performance limitation, there are various hard limits to ensure the game don't just nuke itself when your city grew.

I have tree control 1.0 ( https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2960858317&searchtext=tree ) Is there a more current one?

that;s correct one

check though your setup with skyve if there anything else obsolete that causing problems.

I've figured it out. The bldgs I'm using have large courtyards. So placing plants in the yard was like placing them "in" the bldg. Which the tree control was deleting.