I have a Meyer lemon tree that I keep indoors. It’s often full of blooms and the flowers smell wonderful. I’m always looking for lemons to start growing, but the flowers dry up and fall off and I never get any fruit.
As long as the tree is indoors where the air is still and there aren’t any insects flying around, your Meyer lemon will most likely continue to be a delightfully fragrant but non-fruit-bearing plant. What the flowers need to produce fruit is the process of pollination.
You’ve heard of the birds and the bees, right? Outdoors, flying insects (bees and other pollinators) go from flower to flower, dipping into the pollen on the stamens – the cluster of thin filaments — and spreading it to the stigma at the center of the flower.
Indoors, if you want fruit, you’ll have to take care of that little detail yourself. Lemon trees are self-pollinating, meaning that the flowers shed pollen directly onto the stigma, but they still may rely on wind or insects — or human intervention, if necessary — to shake things up.
Here’s how you can help: As the flowers open, use a cotton swab or a small artist’s paintbrush to collect pollen from the anthers (the tips of the stamens), then rub the stigma with the swab to transfer the pollen. It’s a slow process, but the tree should begin to produce lemons (which grow fairly slowly, by the way).
Meyer lemons growing indoors where winters are cold need a lot of sunlight, and they also benefit from time spent outside when the weather warms up. Place a lemon tree in a protected spot outdoors, moving it gradually into full sun, when nighttime temperatures stay above about 50 degrees. Outdoors, the bees will do the job of pollinating the flowers, of course.
In general, Meyer lemon trees thrive in good potting mix in a container that drains well. Make sure the soil doesn’t dry out completely, but don’t overwater it, either. Fertilize regularly with an organic fertilizer designed for citrus, following directions on the label. (I’ve used Espoma’s Organic Citrus-tone citrus and avocado food, with good results).