Lemon trees are lower-maintenance than some other citrus trees, making them a suitable choice if you do not have citrus-growing experience. Lemon trees also do not require the hot weather that is needed for oranges and grapefruit to grow, so you can grow them in cooler climates.
One key factor in how long it will take a lemon tree to bear fruit is the age of the tree when you planted it outside or in a pot. On average, it will be two years from the time the stem has been grafted to rootstock before it begins to flower and bear fruit
Flowers to Fruit
It takes approximately seven months for the fruit to develop and ripen once the tree blooms. It is not uncommon to have both flowers and fruit on the tree at the same time.
Because lemon trees continually bear flowers that will develop into fruit, you will be able to harvest lemons from your tree throughout the year. In a bad year, you may only be able to harvest a few times, but it can be as many as 10 times in one year.