my usual rule for control powers is "2 accuracy, 2 durations, and 2 recharges in everything (or, 1 recharge 1 end redux)"
but for carrion creepers i would pop in 3 recharges (like you would for ice slick), 1 acc, 1 immob and 1 slow and for fly trap, 2 acc 3 damage and possibly 1 immob (but i've not seen fly trap in action yet).
I would get 3 damage in creepers. The numbers may seem small as they float up but if you have 10 creepers out all lashing away and doing AoE immobs when something dies then the damage really adds up.
Currently, I have Strangler, Seeds of Confusion, Vines, Spirit Tree, Carrion Creepers and Fly Trap. I used the respecs to test out the other powers and found them to be pretty, in a word, useless within my playstyle.
Strangler deserves the whole six slots - 2 ACC 2 REC 2 HOLD.
Vines is my "Oh [censored]!" power, and so don't feel the need to slot more than 2 ACC. I may slot an extra ACC in the future though, because when I use it, I want to make sure it hits. I use it more to hinder enemies, rather than a full-on hold, ie i may follow it up with Seeds as soon as they're recharged.
For creepers, 3 REC 2 ACC should do the trick, add a slow for good measure if you want. I went against IMMOB because the point of the creepers is to knockdown (A better method of controlling than immobilizing) I would go against damage because, a] You're whole secondary is damage and b] The creepers do accuracy checks, as amongst everything else, a vine spawns for ever defeated mob. Also the vines throw thorns which slows down mobs, so you want it as a form of control first.
With Seeds, you can go with 3 REC 2 ACC, adding an extra slot for ACC or CONFUSE DURATION. (The former works fine for me)
The pet is more annoying than useful - I think I like him as more of an accessory 
- anyway....3 DMG 2 ACC should be fine.
I took Spirit Tree because I had nothing else to take - I feel is does help in weird way, although causes a massive obstruction. 3 HEALS is the way to go. The team shouldn't be bad enough to put RECS in this, unless you're planning to PvP.
@Under Control
I don't find that Creepers knocks down all that much...but seeing as critters attack the creepers before they attack you that doesn't concern me to much. From what I understand enhancing creepers with imob would enhance the duration of the imob efect that they have (IE spawning immobs if they kill an enemy) it wouldn't effect the knocking down of the first part of their attack.
My creepers are slotted 1acc, 3 recharge, 2 damage. I find the damage adds up and immobs/slows seem unneeded
Thanks alot guys, should help alot.
Also can you help me with, what powers to take and how to slot Fiery assult, thanks 
The only 'guide' I could find, when I wanted to make a plant/fire.
I've got a plant/fire (a baby one, only 19) but here are my thoughts.
This is a great fun build. You probably want to get ASAP...
Seeds of Confusion (six slot)
Hasten
Fire Breath - seeds tends to cluster mobs up into a nice tight fiery breath shaped target
Fiery Embrace. Click this just before you start your attack chain. It lasts a surprisingly long time for a what it does, especially for your secondary.
I take plan on taking combustion to maximise the aoE carnage, despite the fact it isn't meant to be that great, because it can be used to maintain domination between mobs.
I'll hunt out my planned build but I'm still finding my way through so it is a bit ropey. It is very tight on slots.
Synaesthetix:if your mum wasn't already dead I would go kill her for bringing
you into the world
Hi there, I rolled my Plant/Fire Dom a few weeks ago and she rocks! Possibly the most fun toon to go soloing with IMHO. So far, my slotting has been in this kind of pattern:
Controls - 1/2 Acc, 3 Duration, 1 Recharge.
Assault - 1 Acc, 3 Damage, 1 Recharge.
That seems to do me pretty well and the damage isn't half as bad as I thought it might be.
@Dante EU - Union Roleplayer and Altisis Victim
The Militia: Union RP Supergroup - www.themilitia.org.uk
All depends on how you want to build it. I've skipped incinerate (melee eep!), blazing bolt (snipes on doms... im always bloody moving, whats the point. Snipes good on blasters or below lvl32 IMO) and combustion (damage is pants and you need to be too close). I'd suggest 6 slotting Consume if you're running without stamina (3 rec, 2 acc, 1 end mod) and add in another ACC to your attacks when you start taking on +2 cons or higher. Depends how many slots you have really, i find with hasten on, I don't need the recharge reduction on assault powers.
Soloing with doms on vicious is easy; and its not so hard on relentless (just takes longer). Spam holds on anything that moves; confuse if it gets difficult or the mood takes you (you'll get through missions faster, but suffer a slight drain in short term XP gain (long term, its faster as you're getting mish bonuses faster)).
Ive never made a dominator before or a controller so i really dont know how to slot any hold,confuse etc powers.
Ive gone for a Plant/Fire dominator and just need help with slotting, well all of my plant powers.
Thanks