Gasha Seed

Gasha Seeds, Gasha Trees and Gasha Nuts are objects in the Oracle series.

Location and Uses
Gasha Seeds are small, raindrop-shaped seeds commonly found in Labrynna and Holodrum within chests, from non-player characters, or in certain shops. They can be planted in Soft Soil, where they will eventually grow into a Gasha Tree, which bear Gasha Nuts.

Once a Gasha Tree's Nut has reached its final stage of maturity, Link can cut down the fruit with his Sword and open it up. What lies inside the nut can vary between a Piece of Heart (one-time only), Magic Rings, Hearts, Rupees and Magic Potions. When a Gasha Ring is worn, the contents of a Gasha Nut will supposedly become more valuable.

Growth Rate
What determines how fast Gasha Trees grow and how rare the contents of a Gasha Nut will be is never explicitly revealed in the game, but helpful tips are often dropped by Bipin:
 * "The place, planter and the planter's deeds affect what the nut produces."
 * "The contents of a Gasha Nut depend on where the seed was planted."
 * "Inside a Gasha Nut? More than anything, you find Magic Rings, but sometimes you find Rupees or Hearts."
 * "Finding new places to plant Gasha Seeds and finding secret stairways seems to be good for Gasha Nuts. And helping those in need is good for Gasha Nuts."
 * "My experience holds that planting Gasha Seeds in strange spots produces more rare and unusual results!"
 * "A traveler once told me the time it takes for a planted Gasha Seed to mature into a tree is related to how many monsters you slay. Could this be true?"

His hints basically mean the following:
 * A Gasha Seed matures as Link defeats enemies. The more enemies Link defeats, the more likely he'll get a rare item.
 * Difficult to reach or out of the way locations will have a higher likelihood of rarer items, depending on how out of the way it is.

A mature tree's contents are still purely random, although with various modifiers to various types of items. Saving the game before cutting it and resetting the system will change what is inside the nut as it's not chosen until Link cuts the nut down.

Etymology
Gasha Seeds are likely named after the similarly functioning Gashapon, with their Japanese name being based on the alternative spelling "gachapon."