After you get the Wooden Sword, you can reach the Maku Tree and get the key to Gnarled Root Dungeon.
Go to the Dungeon
Now that you have the Gnarled Key, use the north exit of Horon Village to go to the screen where Impa is. Go east from there, then north, then cut the bushes and go north again, then go west across the bridge. Push on the keyhole to use the Gnarled Key. The Gnarled Root Dungeon entrance will rise up from the ground.
Get a Key
Go north from the entrance. There are four blocks in this room. Push the upper-right one to open the doors. Go through the east door. Kill all of the Stalfos in this room to make a key fall from the ceiling.
Get the Map
Go west from where you got the key. Use the key on the door in the west wall. Kill all of the Stalfos in this room to make a chest appear. Open the chest to get the Map.
Get a Gasha Seed
Go north from the room where you got the map. There is a mine cart at the top of this room. Walk into the cart to get inside. It will automatically roll into the next room.
When the mine cart drops you off, go to the west side of the room. Defeat all the monsters, then push the middle block to unlock the door on the left (you can't push it until you defeat all the monsters in the room). Trigger the blade traps by walking between them and then walking away from them before they can hit you. Walk past them when they are slowly moving back toward their original spots. Go through the west door.
There is a block puzzle in this room. First, go to the block that is to the left of the rightmost block, and push it up or down. Then go to the block to your left and push it left. Next, go to the block to the right of the bottom-left block and push it down. Then push the block left of you to the left. Now you can access the chest, which contains a Gasha Seed.
Get the Compass
Go east from the room where you got the Gasha Seed, then go up the stairs on the right side of the room. Keep going to the right until you reach a chest. It contains the Compass.
There is a lever to the left of the chest that contained the compass. Hit that lever with your sword to switch the train tracks below. Exit to the west.
Go down the stairs and hop into the mine cart. It should take you east twice instead of east then south. You will pass by a treasure chest. After the mine cart stops, walk west and open the chest to get bombs.
Get a Second Key
Go east from the bombs and go up the stairs. Go east, then down the stairs. Go toward the right side of the room, but be careful of the spinning blade trap, which will move toward you when you walk past. On the right side of the room, there is a switch. Step on it to make a chest apppear. Open it to get a key.
Reach the Mini-Boss
Go back the way you came. After you go up the stairs, continue west until you see cracks in the north wall. Drop a bomb there to open it up.
Make your way carefully through this area full of blade traps to reach the locked door in the north wall. Open it and go through.
Mini-Boss: Brother Goriyas
The Brother Goriyas will move around the room throwing a boomerang to each other. The boomerang will follow a curving path when thrown. Avoid getting hit with the boomerang (the shield can protect you) and hit the brothers with your sword until they are defeated.
Get the Seed Satchel
After you defeat the Brother Goriyas, exit west. Push the leftmost block up to access the stairs. Go down.
Use the ladders to reach the seed satchel. It contains 20 ember seeds. You can use ember seeds to light torches and set things on fire.
Get the Boss Key
Go back upstairs. To get out of the blocks surrounding the staircase, push the block that is just below the leftmost block. Go east and use the warp point in the mini-boss room. You will go back to the room where you first got into the mine cart. Go to the left side of the room and use an ember seed on the torches to open the door. Go through.
Kill the monsters in this room to make a chest appear. Open it to get the Boss Key.
Get a Ring
Exit the room where you got the boss key. Then go south, then east, and push the top-right block. Go through the east door, then use ember seeds on the torches at the north end of the room. Go through the door that opens.
Be careful of Wallmasters in here. Go to the upper-left side of the room and open the chest there to get a ring.
Reach the Boss
From the chest where you got the ring, go to the upper-right corner of the room and exit east from there.
There are more Wallmasters in here, so avoid them and go to the boss door in the north wall. Open it and go through.
Aquamentus was in the original Legend of Zelda game for the NES. In Oracle of Seasons, Aquamentus floats down from the ceiling. When he lands, hit his horn repeatedly. He may eventually charge to the left side of the room, so keep your distance. He might also walk toward the left side of the room, spitting three fireballs at different angles. When he does this, try not to stay too close to his face or you won't be able to avoid the fireballs. He moves his head back before spitting fireballs, giving you a chance to move out of the way.
Get the Essence
After Aquamentus is defeated, you can go to the east to get the Fertile Soil.
Now that you have Ember Seeds, you can get some new things in Horon Village.
Items in Horon Village
Go back to Horon Village. In Mayor Ruul's house, you can bomb the wall to the right of the mayor. In the hidden room, there is a Gasha Seed.
There is a Piece of Heart in plain sight in Horon Village south of Mayor Ruul's house. You can get it now by burning the small tree in front of it with an ember seed.
If it is not winter in Horon Village, exit and enter until it's winter there. In the southern part of Horon Village, there is a house with a fenced in area where you can see a treasure chest. First, go into the house and use an Ember Seed on the torch. You will receive the Cuccodex.
Then, if it is winter in Horon Village, use a bomb on the cracked wall in the house where got the Cuccodex to reach the chest in the fenced area outside. It contains 20 rupees.
Go north from Horon Village, east from Impa's house, north from the cat in the tree, and keep going north until you see a bridge to the west. Go east here, then north from the screen with the tree stump. Go into the house here and you find a girl surrounded by Cuccos. Talk to her to give her the Cuccodex. The girl will give you a Lon Lon Egg. The next time you bump into Maple, she will take the Lon Lon Egg and give you a Ghastly Doll.
When you're ready, go east from Horon Village to the Eastern Suburbs.