How do I get good trees?

I want to keep the game limited to only requiring Half Life 2, but I still have TF2 and all the Half Life 2 games. Where can I download trees? And how can I compress stuff into the .bsp so they don’t need to download something to play it? Like I don’t want them to have to download a game to play the map, or props to see them in the map.

Foliage Pack

Pakrat v.95
[li]Using Pakrat

Sweet, thanks again, but how do I install the foliage into my map?

Extract the package content to the like directories under the game files for the game you’re mapping for.