First White Tree
The first White Tree of Gondor came from a fruit that Isildur, at great personal risk, managed to steal from Nimloth the Fair, the White Tree of Númenor, before that one was destroyed at Sauron’s insistence. He suffered many wounds at this mission, and he came near death, but when the first leaf opened in the spring, Isildur was healed of his wounds.
This sapling was brought to Middle-earth on Isildur’s ship, and it was eventually planted in Minas Ithil before the house of Isildur. But when Sauron returned to Middle-earth, he launched a sudden attack that captured Minas Ithil, and he destroyed the White Tree. Isildur escaped taking with him again a sapling.
Second White Tree
In the Year 2 of the Third Age, Isildur plants the seedling of the White Tree in Minas Anor.
This White Tree lasts until TA 1636, when the Great Plague hits Gondor, killing among many others King Telemnar and his children.
Third White Tree
A third sapling is planted in TA 1640 by King Tarondor. This one lasts until the year 2852 and the death of the Ruling Steward Belecthor II.
At this time no seedling of the tree could be found. As a result it was left standing after its death.
Fourth White Tree
When Aragorn becomes king he discovers (with Gandalf’s help) a sapling of the White Tree upon the slopes of Mindolluin, high above the city, which he reverently plants in its place. The dead tree is removed from the court but is placed in the Tombs of the Kings with all the honour that would normally be accorded a fallen monarch. In June of TA 3019 the sapling blooms.