It is forbidden to derive benefit from the fruit of a fruit tree, whether of a Jew or of a non-Jew, even if they grow in a flower pot¹ 294:64. But Rashi, Rosh and Tur hold this is true only for pottery and not for wood. without a hole on the bottom, until after three years from its planting. It is also forbidden to derive benefit from their pits and skins. These three years are not reckoned from day (of planting) to day. Rather if you planted a tree before the sixteenth day of the month of Av, since there are still forty-four days to Rosh Hashanah, they are counted as one year, because it takes fourteen days for it to take root, and thereafter, the thirty remaining days of the year are counted as a full year. We then count two more years from the month of Tishrei (from Rosh Hashana).² But if the tree was planted after the sixteenth of Av, that part of the year is not counted at all, and you must count three years from Tishrei.³ 294:10 they are permitted immediately. According to Chazon Ish they are not permitted until the 15th Shevat.

footnotes: ¹ Of pottery or wood—Rambam, Shulchan Aruch, Gra ² They are not permitted until after the 15th of Shevat. ³ According to Shach

The fruit of the fourth year's growth are called neta revai (growth of the fourth year) and must be redeemed. How does one redeem them? You pick them after they are fully ripe, and take a silver coin or produce that is permitted to eat, to the value of a perutah,⁴ 294: 17 and Sheilas Ya’avetz vol. 2 Responsa 19–20. and say: "With this I redeem these fruits of the fourth year." You then take the coin or the produce, destroy it and throw it into a river. You do not recite a berachah on the redemption of neta revai that grew outside of Eretz Yisroel.

footnotes: ⁴ See Shulchan Aruch

Whether you have planted a seed, or a branch or transplanted a tree you must consider the fruit as orlah. However, if you graft a branch upon a tree, or if you are mavrich, which means making a hole in the ground, and bending one of the branches of the tree, and inserting the middle of the branch in the ground, leaving the end protrude above the ground; even if it was (later) cut off from the trunk of the tree; in lands outside Eretz Yisroel, the laws of orlah do not apply.

If a tree was cut down, and one tefach of stump remains above the ground, then whatever grew out of that stump is not subject to the laws of orlah. But if the stump is less than a tefach high, whatever grows out is subject to the law of orlah, and we count its years from the time the tree was cut down. If a tree was uprooted and some of its roots remained attached to the ground, even if they are as thin as a needle used for stretching the garment after weaving, it is a fact that it can sustain itself without additional earth, and its fruit is not subject to the law of orlah, even if you added much more dirt.