In the published Silmarillion, there's no hint as to the length of the Years of the Trees (except a rather vague reference to 'long ages' in chapter 3). However, a document does exist that gives more precise measurements, The Annals of Aman in volume 10 of The History of Middle-earth. That is the source of the precise figure of 14,322 years, though it should be said that this unpublished figure was subjected to extensive editing, and should not be considered completely reliable.
2
Two other, less certainly canonical, names are also recorded for this Tree. Its name translated into Old English as Goldléoþ ('Gold-song'), while in the language of the Valar themselves it was said to have been called Tulukhedelgorús. (These names come from volumes 4 and 9 of The History of Middle-earth, respectively.)