Rooftrellen's Revenge - Foot Drinkers Unite! (Support Guide)

Even in the late game, most supports will have more impact with stuff like sheepstick instead of right klick items.

Every game is different. You never know when you'll need to contribute to right click damage (Silencer popping ultimate mid fight or something to that extent).
It's not that it's a bad idea to eventually pick up carry items on ANY hero.
The problem is is that typically as a support (even as #4), it is unlikely you'll be getting enough farm (unless your team loves you and leaves some space for you to farm, which is highly unlikely) to be 6-slotted, much less pick up high-cost carry items.

However, I would think that a Blink Dagger would be much more effective in the early-mid game as you can maintain invisibility while blinking next to another set of trees and give you an initiation tool with Overgrowth if the enemy team has wards/gem.

Hmm why would you list carry treant items in support guide.

Maelstorm is a carry treant item, no #4 treant would ever build it.

In the "Pros / Cons" section I would change:

• "Is easy to first hit with his base damage"
  
  into:
  
• "He is able to lasthit/deny effectively due to his high base damage"

First-hitting is not a good term. It means, that he is looking for occasions to hit units FIRST. From the start. Like: Lane creep has full HP, so Treant Protector is going to hit him, because he has high base damage.

I would also add some combos with his ultimate - Overgrowth. Explain how this kind of skill cripples the enemies. Show us differences between entangelment and stun. Similarities to Naga Siren's Ensnare or Meepo's Earthbind.

Tell us why Maelstrom is in your luxury items list. If I would consider this item, I would first build Hyperstone, and then Maelstrom into Mjollnir, but why? It says that's support guide.

Extend this guide. I know you can do it.

You list Maelstrom as a luxury. Why? Why would any human ever get that on Treant Protector
Moreover, the starting build has no regeneration in it.
I realise you said you were relatively new, but that's just a simple thing to do. Living Armor Isn't the only hp regen you should use.

Also, (as mastadoom has already mentioned) ik you said you weren't gonna go into meta and tactics and stuff, but all you've done is described skills and a sliver of supporting detail. I am personally a terrible Treant Protector player myself though.

Yes absolutely, but knowing how to use the skill, and being given examples can separate a good guide from a great guide.

You could Google a lot of things but I think the orange elaborates on how to use the skills...

I know you said you wouldn't be going into tactics and things, but I feel you should at least give some info on how to play him, because you have basically listed information I can google.

Also with out a Blink Dagger you can't land your ult effectively, so that is 100% core in my opinion. On top of that, your starting items have no regen in it. You should probably go something like this: Animal Courier, observer wards, Tango, ClarityX2, iron branchesX2.

Also, the Maelstrom isn't really a good items for tree, be cause he isn't a right clicker.