Do you need two lemon trees for cross pollination to produce fruit?
Lemon Tree Pollination
Certified GKH Gardening Expert
They are, like many citrus trees, self pollinating. While they do not require another tree to produce fruit, they still require a little help from nature (i.e. bees). If there are not enough natural pollinators around, the tree will have difficulty producing. This is why we sometimes have to intervene by hand pollinating. So if the blossoms are not getting pollinated, they will shrivel up and drop. Pollinating the flowers by hand will help in this case by using a small paint brush and swirling it around the inside of the flower, repeating on all the flowers. You can also encourage additional pollinators to the area. Here is more information on that: https://www.gardeningknowhow.com/garden-how-to/beneficial/insect-pollination-process.htm and https://www.gardeningknowhow.com/garden-how-to/beneficial/creating-a-pollinator-garden.htm If, however, you do not get blossoms at all, this could signal a lack of nutrients - namely phosphorus. For more information on non-fruiting issues in lemon trees, this article will help: https://www.gardeningknowhow.com/edible/fruits/lemons/lemon-tree-not-fruiting.htm