Grass is an underestimated type that catches a lot of people off guard. I have been working to create the perfect grass team for about a year now and with three tournament victories, the biggest being a sixteen person round-robin tournament, I feel that I'm closing in. However I'm never content and I as I search for ways to get stronger I ended up here. So without further ado, here is my team.
Ferrothorn
Item: Rocky Helmet
Ability: Iron Barbs
Nature: Brave
EV's: 252 Atk, 168 SpD, 48 Def, 40 HP
Moves:
Power Whip
Gyro Ball
Stealth Rock
Leech Seed
Ferrothorn is my main lead. He's meant to get stealth rocks out and deal as much damage before going down. I don't think I'll put spikes on it since Ferrothorn never seems to last that long in a battle. The two attacks are there for type coverage, especially against water teams. With a type littered with ice beams it's important to be able to OHKO just about any water pokemon that crosses my path.
Sceptile
Item: Choice Scarf
Ability: Overgrow
Nature: Modest
EV's: 252 SpA, 252 Spe, 4 HP
Moves:
Giga Drain
Focus Blast
Hidden Power Fire
Dragon Pulse
Sceptile is one of my sweepers. I prefer this set over the swords dance set because I can normally outspeed any threat and take them down before they end up sweeping my team. Another point is that my team is mostly physical attackers so Sceptile is nice to have to break those physical walls. Sceptile never loses its held item so unburden isn't necessary.
Jumpluff
Item: Flying Gem
Ability: Chlorophyll
Nature: Adamant
EV's: 252 Atk, 252 Spe, 4 HP
Moves:
Swords Dance
Sleep Powder
Acrobatics
U-Turn
Jumpluff is my main bug counter and wall breaker. Most people expect a more supportive set so the element of surprise isn't a bad addition. Jumpluff rips through teams that aren't prepared by casting an opposing pokemon to sleep and powering up with a swords dance. It also OHKO's Volcaronas that aren't boosted by a quiver dance. Jumpluff is also my lead against sun teams to eliminate Ninetails, or put a dent in Heatran.
Breloom
Item: Focus Sash
Ability: Technician
Nature: Jolly
EV's: 252 Atk, 252 Spe, 2 HP
Moves:
Spore
Swords Dance
Mach Punch
Bullet Seed
Breloom finds itself on just about every grass and fighting team and doesn't need much explanation on why it makes my team. My Breloom is running your standard techniloom set meant to break substitutes and sweep teams after they have been weakened.
Shiftry
Item: Leftovers
Ability: Chlorophyll
Nature: Adamant
EV's: 252 Atk, 252 Spe, 4 HP
Moves:
Swords Dance
Sucker Punch
Seed Bomb
Brick Break
Shiftry is there to counter psychic and ghost teams. I can normally revenge kill a would be sweeper, but with Shiftry's frailty I'm lucky if I can get a swords dance up. I tried out Cacturn for a while, but found myself switching over to Shiftry for the better speed and ability.
Tangrowth
Item: Leftovers
Ability: Regenerator
Nature: Modest
EV's: 252 HP, 252 Def, 4 Spa
Moves:
Giga Drain
Hidden Power Ice
Focus Blast
Synthesis
Tangrowth is there as my physical wall. Not a single, unboosted brave bird has been able to OHKO Tangrowth, while I can strike back with a super effective HP Ice to KO that pokemon. Tangrowth also does very well against fighting teams as most of them are physical attackers. If Ferrothorn is gone then Tangrowth is my backup outrage cushion. An outrage on average eliminates around 35% of Tangrowth's health to give you an idea of its bulk.
Threats:
Heracross has swept my team once Sceptile is gone on numerous occasions. Even Tangrowth can't seem to stop Heracross after a moxie boost.
I always find it difficult to KO a Crobat and it ends up costing half my team to bring it down.
Sableye never sweeps my teams, but it's always a struggle to bring down with prankster. I always get a couple burns and it becomes nearly unstoppable once Sceptile and Tangrowth are gone.
Dragon Teams
No dragon in particular devastates my team, but a whole team of them makes it much harder for me to win and is probably the type I lose to the most.
Fire Teams
The first enemy of grass still remains one of my fiercest. If Jumpluff misses that first Sleep powder and gets KO'd then my entire team seems to crumble.
Steel Teams
With focus blast being an unreliable move Steel is a top threat as grass moves won't do too much.
Well thanks for taking a look at my team, and I'm open to any criticism, or strategy suggestions that you can offer.
Ferrothorn

Item: Rocky Helmet
Ability: Iron Barbs
Nature: Brave
EV's: 252 Atk, 168 SpD, 48 Def, 40 HP
Moves:
Power Whip
Gyro Ball
Stealth Rock
Leech Seed
Ferrothorn is my main lead. He's meant to get stealth rocks out and deal as much damage before going down. I don't think I'll put spikes on it since Ferrothorn never seems to last that long in a battle. The two attacks are there for type coverage, especially against water teams. With a type littered with ice beams it's important to be able to OHKO just about any water pokemon that crosses my path.
Sceptile

Item: Choice Scarf
Ability: Overgrow
Nature: Modest
EV's: 252 SpA, 252 Spe, 4 HP
Moves:
Giga Drain
Focus Blast
Hidden Power Fire
Dragon Pulse
Sceptile is one of my sweepers. I prefer this set over the swords dance set because I can normally outspeed any threat and take them down before they end up sweeping my team. Another point is that my team is mostly physical attackers so Sceptile is nice to have to break those physical walls. Sceptile never loses its held item so unburden isn't necessary.
Jumpluff

Item: Flying Gem
Ability: Chlorophyll
Nature: Adamant
EV's: 252 Atk, 252 Spe, 4 HP
Moves:
Swords Dance
Sleep Powder
Acrobatics
U-Turn
Jumpluff is my main bug counter and wall breaker. Most people expect a more supportive set so the element of surprise isn't a bad addition. Jumpluff rips through teams that aren't prepared by casting an opposing pokemon to sleep and powering up with a swords dance. It also OHKO's Volcaronas that aren't boosted by a quiver dance. Jumpluff is also my lead against sun teams to eliminate Ninetails, or put a dent in Heatran.
Breloom

Item: Focus Sash
Ability: Technician
Nature: Jolly
EV's: 252 Atk, 252 Spe, 2 HP
Moves:
Spore
Swords Dance
Mach Punch
Bullet Seed
Breloom finds itself on just about every grass and fighting team and doesn't need much explanation on why it makes my team. My Breloom is running your standard techniloom set meant to break substitutes and sweep teams after they have been weakened.
Shiftry

Item: Leftovers
Ability: Chlorophyll
Nature: Adamant
EV's: 252 Atk, 252 Spe, 4 HP
Moves:
Swords Dance
Sucker Punch
Seed Bomb
Brick Break
Shiftry is there to counter psychic and ghost teams. I can normally revenge kill a would be sweeper, but with Shiftry's frailty I'm lucky if I can get a swords dance up. I tried out Cacturn for a while, but found myself switching over to Shiftry for the better speed and ability.
Tangrowth

Item: Leftovers
Ability: Regenerator
Nature: Modest
EV's: 252 HP, 252 Def, 4 Spa
Moves:
Giga Drain
Hidden Power Ice
Focus Blast
Synthesis
Tangrowth is there as my physical wall. Not a single, unboosted brave bird has been able to OHKO Tangrowth, while I can strike back with a super effective HP Ice to KO that pokemon. Tangrowth also does very well against fighting teams as most of them are physical attackers. If Ferrothorn is gone then Tangrowth is my backup outrage cushion. An outrage on average eliminates around 35% of Tangrowth's health to give you an idea of its bulk.
Threats:

Heracross has swept my team once Sceptile is gone on numerous occasions. Even Tangrowth can't seem to stop Heracross after a moxie boost.

I always find it difficult to KO a Crobat and it ends up costing half my team to bring it down.

Sableye never sweeps my teams, but it's always a struggle to bring down with prankster. I always get a couple burns and it becomes nearly unstoppable once Sceptile and Tangrowth are gone.
Dragon Teams
No dragon in particular devastates my team, but a whole team of them makes it much harder for me to win and is probably the type I lose to the most.
Fire Teams
The first enemy of grass still remains one of my fiercest. If Jumpluff misses that first Sleep powder and gets KO'd then my entire team seems to crumble.
Steel Teams
With focus blast being an unreliable move Steel is a top threat as grass moves won't do too much.
Well thanks for taking a look at my team, and I'm open to any criticism, or strategy suggestions that you can offer.