Minecraft

All you need for this is three bricks which is acquired from smelting clay which is usually found underwater in rivers or lakes. Smelt the clay into three bricks and you can craft the pot and place it for the achievement.

If you're having difficulty finding clay in your own world there's a very quick and easy way around this.
1. From the main menu choose Play, Create New and then Create New World.
2. Under the game settings choose Survival and Peaceful difficulty. Scroll go down to Seed and click the arrow to the right of the text box. Choose the pre-defined "Cliffside Village" map. Enable the "Show Coordinates" option and then click Create. The actual seed for the map is -334399639 if anyone's interested.
3. Spawn in, look behind you and you'll see a pool of water. There's some clay in there at coordinates 356, 63, 7 (you only need a total of 3 clay).
3. Punch a tree for wood and make a crafting table. Make a wooden pickaxe.
4. Mine some stone and make a furnace.
5. Use wood as fuel to smelt 3 clay into 3 bricks, then use the Crafting table to make the Flower Pot.
6. Plant the Flower Pot to get your achievement.

This game seems to have a delay between meeting the criteria and the achievement popping. Don't know if that's because I'm playing in Realms or if it's just how the game is but I always have to wait 5-10 seconds before my achievements actually show up.

Constructive criticism always welcome. Happy to revise the solution if anything's unclear. Happy hunting!

The solution to this achievement is quite simple:

First, find a river/ocean, then search underwater for clay. When you find some clay, break it and you will get 4 clay, smelt it in a furnace and you will get some bricks. You will need 3 bricks to craft the pot. Once you have crafted it, simply place it and you will get the achievement.

I hope this helps.