Some cards I made up...

[topspin1617]

Seedsower
******
EARTH/Plant
Pay 800 life points in order to Special Summon one Seed Token (EARTH/Plant/500 ATK/500 DEF) to your side of the field. A Seed Token may not attack or be tributed on the turn you Summon it.
2200 ATK/1700 DEF

Ensnaring Vines
***
EARTH/Plant
Remove 2 Plant-type monsters in your graveyard from play in order to take control of 1 face-up monster on your opponent's side of the field until the end of the turn. As long as that monster is under your control, it is treated as being a Plant-type monster in addition to its usual type. This effect may only be used once per turn.
1300 ATK/800 DEF

Creeping Ivy
****
EARTH/Plant
When this card is destroyed as a result of battle, you may Special Summon 1 Plant-type monster with 1500 or less attack from your deck. Then shuffle your deck.
1400 ATK/1500 DEF

Sprout
****
EARTH/Plant
When this card destroys a monster as a result of battle, Special Summon 1 Sprout Token (EARTH/Plant/400 ATK/0 DEF) to your side of the field. Increase the attack of all Plant-type monsters on your side of the field by 500 for each Sprout Token on your side of the field.
1400 ATK/1000 DEF

Malice Roots
DARK/Plant
********
This card cannot be Normal Summoned or Set. This card is Special Summoned by Tributing X Plant-type monsters on your side of the field. Increase the original attack of this monster by 900 for each Plant-type monster tributed to Special Summon this monster. In addition, this monster gains the following effects according to the number of Plant-type monsters tributed to Special Summon this card:
1: When this card attacks a defense position monster, and that monster's defense is less than this card's attack, inflict the difference as battle damage to your opponent's life points.
2: Effect 1, and as long as this card remains face-up on the field, it is unaffected by the effects of Effect Monsters, Spells, and Traps that target.
3: Effect 2, and whenever this card destroys a monster as a result of battle, draw 1 card from your deck.
4: Effect 3, and once per turn, you may Special Summon 1 Plant-type monster from your graveyard. If you use this effect, this monster may not attack this turn.
5: Effect 4, and once per turn, you may pay 1000 life points to destroy 1 card on your opponent's side of the field. If you use this effect, this monster may not attack this turn.
500 ATK/1500 DEF

The Great Mana Tree
Spell - Field
Increase the attack of all Plant-type monsters on the field by 500. In addition, whenever a Plant-type monster is destroyed, the owner of that monster gains 300 life points for each star level of the destroyed monster.

Regeneration
Trap - Continuous
As long as this card is face-up on the field, whenever a Plant-type monster you control is destroyed as a result of battle, you may Special Summon 1 Plant-type monster from your graveyard with a star level less than that of the destroyed monster.

Extending Vines
Spell - Normal
Select one face-up Plant-type monster on your field to activate this card. Special Summon one Plant-type mosnter from your deck with a star level less than or equal to the selected Plant-type monster.

Fire Mage
****
FIRE/Spellcaster
During each of your Standby Phases, place 1 Spell Counter on this card. During your Main Phase, you may remove all Spell Counters on this card to inflict 800 points of damage to your opponent's life points per Spell Counter.
1800 ATK/1000 DEF

Water Mage
****
WATER/Spellcaster
During each of your Standby Phases, place 1 Spell Counter on this card. During your Main Phase, you may remove all Spell Counters on this card to randomly discard one card from your opponent's hand per Spell Counter.
1200 ATK/1500 DEF

Earth Mage
****
EARTH/Spellcaster
During each of your Standby Phases, place 1 Spell Counter on this card. During your Main Phase, you may remove all Spell Counters on this card to destroy 1 monster on the field per Spell Counter.
1700 ATK/1000 DEF

Wind Mage
****
WIND/Spellcaster
During each of your Standby Phases, place 1 Spell Counter on this card. During your Main Phase, you may remove all Spell Counters on this card to return a number of cards on your opponent's side of the field to the owner's deck equal to the number of Spell Counters removed. Then shuffle both players' decks.
1500 ATK/1900 DEF

Master of Arcane Magic
********
LIGHT/Spellcaster
This card cannot be Normal Summoned or Set. This card is Special Summoned by removing the following cards in your graveyard from play: "Fire Mage", "Water Mage", "Earth Mage", and "Wind Mage". During each of your Standby Phases, place 1 Spell Counter on this card. During your Main Phase, you may remove all Spell Counters on this card to remove from play a number of cards on your opponent's side of the field equal to the number of Spell Counters removed.
2500 ATK/1200 DEF

[Souljer]

Very nice cards. The only ones I'm worried about are the Mages. They seem a little broken. Since they generate the tokens themselves, it would be easy to get a +1. People don't always have removal in their hands, and destruction traps are reactive. I'd say double the amount of Spell Counters needed for the regular mages, and the Arcane Mage you can leave alone. (This doesn't apply to the Fire Mage)

I'd give the Fire Mage 1900 attack. Fire doesn't have a 1900, or anything that great... Another thing you could do with the Fire Mage is make it cumulative, so instead of the player popping 800 damage per turn, you can encourage them to wait for the damage to stack. I'm having a block right now, so I can't word it how it would be written on a card, but what I mean is the first counter could count for 600, if it's the only counter on it, but if there are two, they would both count for 800, and if there are three counters, they would all count as 1000, etc...

I'd also up the attack on Water Mage, to either 1300 or 1400.

And some name changes for the Mages, since naming them after an attribute seems a bit bland:
Fire Mage = Scorching Mage
Water Mage = Storm Mage
Earth Mage = Rock Mage
Wind Mage = Tornado Mage

Something like that. Just change their names to something having to do with their "discipline".