Ever since i was a little boy, holding my first magic deck (about 3 years ago) it was my dream to create a deck solely around saprolings and plants.
Taking inspiration from "Saproling vengeance" by Ixidron and the infinite combo from 2x Parallel Lives and at least 1x Jade Mage and at least 1x Utopia Mycon, you can create infinite saprolings.
This combo costs 11 mana in total, but can be reduced if other saporlings are sacrificed by Utopia Mycon or from the doubled manabase from Wild Growth.
However, changes from the main portion of this deck will be the removal of Essence of the Wild because it removes the combo above (since, if the saprolings are no longer saprolings, they cannot be sac'd). Other changes include additions to the amounts of the cards in the deck for the combo above and a few, more minor, replacements.
Ixidron's deck is located here: http://tappedout.net/mtg-decks/saproling-vengeance/
A combo I added myself is the Sporemound and Life and Limb combo. Essentially, Life and Limb makes all your forests and saprolings a forest AND a saproling. Sporemound says whenever you play a forest, summon a saproling. Since all saprolings are also forests, it triggers again, summoning yet another forest saproling, and so on.
However, Sporemound's ability is not a "may" trigger, so sacrificing Sporemound or Life and Limb is mandatory or else the game ends in a draw, according to those pesky limitations I found while researching this combo. If a game is turning out in your opponent's favor, you can intentionally make it a draw with this combo, though that is generally a jerky move. In order to not be a jerk, be sure to have mana for a sacrifice instand and specify after how many occurances you use the sacrifice, and (if mana is low), try to get out a Utopia Mycon for whatever saporlings you have for a mana boost. Beast Within and Artisan's sorrow can do well for sacrifice if you have the mana (especially if Utopia Mycon gives you the mana for each of those creatues you obtained), with some additional gain with a 3/3 beast or scry 2, respecively.
The Sporemound and Life and Limb Combo is 9 mana total by itslef, and requires you to drop a forest or saporling. Getting mana ramp from the 1 mana Utopia Mycon brings the combined mana total to 10 minus however much you can bring out the Utopia Mycon ability, which can potentially bring the overall cost to 0 mana if you have enough saporlings from cards like Fists of Ironwood, which provides saporlings and an aura for trample. Also, keep in mind damage and removals can take out Life and Limb or Sporemound, so try to limit playing one of them a turn before the other.
Both of the infinite saproling combos can benefit from Concordant Crossroads for haste (in case the opponent had a board wipe) and Essence Warden for infinite life gain.
How would one get these combos consistently? Well, every combo here has creatures involved. Worldly tutor that creature up when you have the other components. Warning: the two infinite combos require 3 or more components. Try to tutor only if you have 2 of the components to minimize enemy control decks that manipulate your hand or remove your other components once played.
Lastly, the additional cards: Mycoloth can make use of sacrificing your infinite saporlings and buffing him for +1/+1 per saporling sac'd, and then spits them right back out for free. It's useful in case the opponent has "name and remove all named creature types" effects. Lastly, Plummet removes tricky fliers since there is a lack of reach in this deck.
((Apparently, its spelled saprolings, and not saporlings. I've been spelling and saying it wrong since I got into magic. My recent discovery of the "pro" and not "por" PORtion [get it?] made my title.))
