http://deckbox.org/sets/259557

So far things seem to be working fairly well. What are the weak points and how can they be shored up without subbing in a lot of pricey cards? What should I be sideboarding?

Ok there are a few things that would really help out this deck while staying within a budget. First I'd personally drop the guild gates and the gate creeper and add 2 more plains. Then you should consider farseek or some other mana ramp. Populate can take a while to really get going so mana ramping is very important for the first two turns. I'd add two other cards that have won several games for me Collective Blessing and Sundering Growth. The Sundering Growth allows you to knock out the annoying detention spheres and obilivion rings while also allowing you to populate. That will leave your O-rings so you can stop their stuff instead of using them to get back things. The Blessing is really good for boosting all creatures not just tokens. There is nothing better than hitting someone with a boosted Avacyn's Pilgrim with rancor for the win.

As for the sideboard I'd move the Akroma's Memorial and Growing Ranks to the sideboard. Also I'd possibly add a playset of Coursers' Accord. I would sideboard a couple Heroes' Reunion which alongside the Akroma's Memorial could really save this deck from most Zombie decks. Also you need to drop the number of cards in your main deck to 60.

Those are the things that pop in my mind for now without going the more expensive route which involves Temple Gardens, Thragtusk, and Resto Angels.

Maybe someone else has better suggestions than me but that's what I would do.

I agree with srrogers1985 on the gates.

My only concern is the pace of play. You will really need more ramp--your mana curve looks like you won't get rolling for a number of turns. Consider adding Avacyn's Pilgrim as a one-drop white mana source creature.

Exactly and maybe also add Arbor Elf for ramping. Then when you drop the Collective Blessing everything you put on the board becomes a viable weapon especially with Rancor. Also another thought is to add some flying Lingering Souls and Midnight Haunting are really good for this.

http://deckbox.org/sets/259859

Made a few changes. I'm not seeing how I can add in the things you guys have mentioned and cull down to 60 cards without compromising the spirit of the deck.

Here's my thoughts:

Gatecreeper is my card searcher and also additional defender cards to fuel Axebane Guardians
Axebane Guardians tap for any color mana equal to numer of defenders controlled
Avacyn pilgrims and arbor elves give some mana boost
Ground seal takes graveyards out of play
Sundering growth removes enchantments
Growing ranks and parallel lives are the core of my populate engine
Tokens come from Garruk, call of the conclave, grove of the guardian, and selesnya charm
Life gain from Trostani
Root born defenses and Druids deliverance nullify conventional attacks to allow time for token generation and population
If all works well Wayfaring temples will be my big creatures and further fuel my populate engine

My only problem with the Gatecreeper and Axebane Guardian is that they don't provide any substantial mana ramp until turn four which when facing any aggro deck is too late in the game. Also you need to find a way to put Midnight Haunting in so you can generate some flying tokens.

If I put some Akroma's Memorial back in, with the Arbor Elf/Avacyn's Pilgrim set there to ramp mana, can I get it out fast enough to give all my creatures flying (in addition to all the other things that card gives, like first strike and protection from black and red) and skip the Midnight Haunting?

EDIT: Think I found a solution that keeps both in - http://deckbox.org/sets/259859

Ok that build looks fairly solid. The only thing I see now that you might want to change is to take out two of the Grove of the Guardian and put in two Collective Blessing that way you can make it harder for someone to wipe out your entire board with a bonfire or mizzium mortar. Also if you can put in Temple Gardens and then add some farseeks. With these you should be able to focus entirely on ramping the first 2-3 turns and then have a good mid to late game comeback as things start to stabilize on your side. Otherwise this deck looks like it could be fun to play.

Wouldn't rootborn defenses handle mm or bod? The reason I've got a full set of gotg is to maximize my chances of getting its 8/8 elemental token out and start replicating it ( hopefully in multiples with parallel lives).

I would go with Intangible Virtue long before I would go with Collective Blessing - sure it can win games, but the Virtue provides the tokens (the real focus here) with the bonus AND vigilance, letting them be defenders in the process.

The biggest problem I'm seeing here is that you're open to so much at the start as you're not going to want to block that Loxodon Smiter or other creature with your rampers. For this purpose, you couldn't ask for a better creature than Doomed Traveler. Easy blocker who gives you a 1/1 spirit that you then pump with the virtues - yes please. To that end, Midnight Haunting should probably be a 4x of - do not estimate how powerful flyers are in standard right now. Most people are running some zombie build or something to that effect and you can easily fly right over the top and beat their brains in (why do you think Delver was so nasty and Restoration Angel is still such a big thing).

I would also suggest lowering the counts of Parallel Lives/Collective Blessing to either 2x of each or 3-1 in whichever direction you prefer. If you consider that as a turn 3 or 4 drop (even with the ramping), you're still looking at trading an enchantment that doesn't give you any immediate benefit for their ability to play something much bigger (i.e. Deadbridge Goliath, Splatter Thug, Geralf's Messenger, etc). They're nice, but in reality you want to swarm them as quickly as possible.

I would also say to lower Sundering Growth to 2x in the mainboard and save the other two in the sideboard - sure you can use it for a quick populate fix, but if you don't have artifacts or enchantments to target, you could easily have something better there.

Also, looking at the sideboard (not sure if you're trying to keep this standard legal or not), but Surgical Extraction rotated out. So that'd be a no-go.

You also want to get this down to 60 cards if at all possible.

So, in sum, I would do the following:

-3 Wayfaring Temple (or at least -1)
-3 Sundering Growth (and then +4 in the sideboard)
-2 Akroma's Memorial (with any luck, by the time you have 7 mana you're doing a LOT more, making creatures and are overwhelming them)
-1 Growing Ranks
-1 Parallel Lives
-2 Grove of the Guardian (the 8/8 is nice, but he's slow and hard to get out - the colorless mana doesn't really help you either as almost everything is a white or green symbol)
-2 Forest
-1 Plains (You really will need Temple Gardens to be competitive)

+1 Midnight Haunting
+3 Intangible Virtue
+1-4 (however many you can get) Temple Garden
+3 or 4 Doomed Traveler

These changes SHOULD lower you down closer to 60 and would really hone in more on the idea that you're going to overrun them. I would then make up the sideboard out of removal and stuff (i.e. Pacifism) as your goal isn't to make a bigger creature than them, it's to make a LOT more than them and slide in for the victory (which sort of makes those spirit tokens that much more important). But I've found that without some sort of card draw, anything over 65 cards just won't give you the consistency you want.

And it's alright to be struggling with the idea, as I have a populate build that I'm still working the kinks out of. You can see it here:

http://deckbox.org/sets/239316