In Ocarina of Time there are several patches of soft soil which can be found all over Hyrule. In these patches of ground Link can plant what is called a Magic Bean. Plant them while a kid and when Link grows up they will sprout and make plants that will take you to hidden locations.
Ocarina of Time Magic Bean Plant Locations
Death Mountain Crater
Next to the Death Mountain Crater warp point is a bean bed that will take Adult Link to a heart piece.
This bean bed is in the second left you take while in the Lost Woods. By taking this plant as Adult Link you will be given a shortcut from Hyrule Field to the Lost Woods.
Next to the Lakeside Lboratory is a bean plant which will take Adult Link to a heart piece.
At the end of the Lost Woods is another bean plant that will take you to a golden skulltula.
Near the front and to the left of Kakariko Graveyard is another bean plant. If you ride this plant as Adult Link it will take you to a heart piece.
This bean plant is found right in front of Dodongo Cavern. If you ride the plant as Adult Link it will take you to another heart piece and from there after also provide you a short cut up the mountain.
The last bean plant location is next to the Spirit Temple entrance. Riding this plant will lead Adult Link to a heart piece and a golden skulltula.
This bean bed is located at the beginning of Zora’s River and is in fact right next to a bean seller. As Adult Link you can use this plant to go up Zora’s River much faster.
On the ledge above the river is a bean bed that will once again take Adult Link to a heart piece hidden behind a waterfall.
The first location of the bean bed is behind the Kokiri Shop in the forest. By riding this plan as Adult Link you will be taken to a ledge that is filled with some Rupees.