We have several Meyers lemon trees growing indoors right now. The Meyers lemon is actually a cross between a lemon and a tangerine. It will grow and produce all year round as long as we bring it indoors during the winter. Right now, there is frost on the ground, but our tree is doing great, We put it up against a south facing window to catch enough light during these dark wintery months. When these buds fully emerge, I will take a paint brush and gently tap it on each of the flowers to pollinate the tree (it is a self pollinating tree, but manually moving the pollen around ensures a larger crop) Soon, we will have ripe yellow lemons to eat.
This tree is a great way to get fresh homegrown fruit in your diet this time of year. I highly recommend getting one.
Cheers.