The female parts of all plant blooms require male pollen so they can bear fruit. Lime trees are self-fruitful, meaning their flowers contain both male and female parts, so that they supply their own feces. You can develop Mexican limes (Citrus aurantifolia) or Tahitian limes (C. latifolia) outside in U.S. Department of Agriculture plant hardiness zones 9 through 11. If you develop a lime tree outside, bees and other pollinating insects will transfer the pollen from the male into female pieces. If you develop a dwarf variety indoors, you need to transfer the pollen manually.
Lime Flower Parts
The sticky female stigma is located in the center of this lime blossom. The stigma will develop into limes when it receives feces. The stigma is surrounded by the male parts, called anthers, long filaments which have fluffy yellow grains of pollen on their ends. The transfer of pollen from anther to stigma is called pollination.
Outdoor Pollination
You do not need to plant two lime trees together for the flowers to be pollinated outside; however, you do require foraging bees or other pollinating insects. The bright color of the flowers attracts the mammals that feed on the sweet nectar inside. As soon as a bee bumps against an anther containing male pollen, the pollen sticks into the tiny hairs on its body. When the bee touches the sticky female pistil, the pollen is moved and the blossom can begin developing a lime. The more mammals you’ve got, the more flowers are pollinated and also the more limes your tree will yield.
Pollinating Indoor Limes
You can grow dwarf varieties of this Mexican lime indoors. Dwarf varieties of Mexican limes, also called key limes, grow to about 2 feet tall. This is the smooth, green lime that you normally find in supermarkets. If you develop a lime tree indoors or if you develop it outside but have no mammals, you need to pollinate it by hand.
Pollinating Lime Flowers by Hand
To pollinate a lime blossom by hand, you need to transfer pollen from the male anthers into the sticky female stigma. To do this, collect some yellow pollen with the tip of the finger, a cotton swab or a small, soft paintbrush. Gently transfer a few of the pollen onto the stigma, ensuring some of this pollen stays in place. Repeat this procedure for each flower which you want to develop a lime.