Fertile Ground is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Enchant land Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Complete guide

Fertile Ground is a classic mana-fixing enchantment that turns any basic or non-basic land into a powerful source of extra resources. By enchanting a land, you ensure that every time you tap it for mana, you get a bonus boost of any color you need.

What It Does

Fertile Ground is an Aura with the Enchant Land keyword, meaning it must be attached to a land on the battlefield. It provides a triggered mana ability: whenever the enchanted land is tapped for mana, Fertile Ground's controller adds one additional mana of any color to their mana pool. This doesn't change the type of mana the land normally produces; it simply adds an extra drop of mana on top.

How It Resolves Step by Step

First, you cast Fertile Ground by targeting a land on the battlefield. Once it resolves and enters the battlefield attached to that land, its ability is ready. When the controller of the land activates a mana ability that requires tapping the land, Fertile Ground triggers. Because it is a mana ability, it does not use the stack and resolves immediately, providing the extra mana alongside the land's original output.

Common Mistakes

A frequent point of confusion is who gets the mana. Fertile Ground specifies that its controller adds the mana, not necessarily the owner of the land. If you enchant an opponent's land, you will get the extra mana when they tap it for their own use! Additionally, remember that the land must be tapped specifically for mana to trigger this effect; effects that simply tap the land for other reasons won't grant the bonus.

When to Play It

This card is excellent in multi-color decks that need 'fixing' to cast spells with specific color requirements. It is also highly effective in strategies that involve untapping lands, as you get the bonus mana every single time the land is tapped during a turn.

Interaction examples

Scaling Your Mana

You cast Fertile Ground on your basic Forest. On your next turn, you tap the Forest for one Green mana. Fertile Ground immediately adds one mana of any color (such as Blue) to your pool. You now have two mana available from a single land.

No Direct Synergy

Hardened Scales

If you have Hardened Scales on the battlefield and tap a land enchanted with Fertile Ground, you simply get your two mana. Hardened Scales only interacts with +1/+1 counters being put on creatures and has no effect on the mana production of Fertile Ground.

Enchantment Presence

Garruk's Uprising

With Garruk's Uprising in play, Fertile Ground helps you reach the high mana costs of large creatures more quickly. While Fertile Ground entering the battlefield won't trigger the card draw from Garruk's Uprising (as it is not a creature), the extra mana it provides allows you to cast a creature with power 4 or greater sooner, which then triggers the draw effect.

Guide written with AI from the official text and rulings. Official English text prevails.