I have a lemon tree that I brought in this past october for winter,it is about 6-7 yrs old and shortly after i noticed a flower bud for the first time.It is ready to open any day but that is the only one on the entire tree.Is this because this is its first time to flower or will it continue to bud from here on???Ive waited yrs for this to flower,anyone had the same problem??thanks

What fertiliser are you using?, it could be down to fertiniser , if not fertilised it will not store enough energy to flower, it will mainly flowr in the spring/early summer after a cold winter
More likely it is down to lack of cold hours during the winter, you need to get a large number of chill hours to make it flower in the spring,with too few cold hours it may flower, but not alot, without cold hours it may not flower

If your lemon was started from a seed, it is normal that the tree would only produce a very limited number of blooms at first. Seedling trees undergo the juvenile, transitional and mature phase of development to various degrees, and in different parts of the tree in a gradient from the base to the top. When a seedling tree finally produces the required node count to mature, the entire tree does not miraculously become mature. Therefore only the portion of the tree beyond the required node number will produce a flower. Each season will produce more and more flowers. Finally, do not be to disappointed if the initial bloom does not bear a fruit to maturity. Sometime the first blooms do produce fruit, and sometimes they do not. Congratulations on he fine job you must have done, getting your lemon to this point. - Millet