Hand Pollinating an Indoor Lemon Tree: Should you, and how?

The tart, fragrant, bright, and juicy fruit of a lemon tree is certainly one of the most, if not the most, rewarding and pleasurable aspects of growing a lemon tree. However, many conditions must be right and many processes must happen correctly in order for your lemon tree to bear fruit. One of these processes sometimes overlooked by new indoor lemon tree growers is pollination.

Pollination is a natural process that is necessary for any fruit-bearing plant to bear fruit. However, if you’re a first-time lemon tree grower, pollination might not be something you think of immediately, after all it’s a process that happens in nature without human intervention.

What you might not know is that external forces of nature such as water, wind, butterflies and bees, play a primary role in the pollination of fruit-bearing plants. If you are growing your lemon tree indoors, it won’t have that crucial interaction with the outside forces of nature. Don’t worry, however, as in this case it is easy to do the work of nature by hand.

Read on to find out more about why pollination is necessary, and how you can pollinate your indoor lemon tree by hand.

Why Pollination Is Necessary

Pollination is the process during which a plant becomes fertile and able to bear fruit. If a fruit-bearing tree does not undergo the process of pollination, it will not produce fruit.

Pollination is a part of a plant’s reproductive life cycle. Sperm from ripe pollen must be transferred to the central stigma for a flower to become fertilized and produce fruit. The fruit the plant produces contains the seeds. The fruit with the seeds is either dropped or consumed by animals which then carry the seeds to other areas, expel them as digestive waste. When conditions are right, new plants will grow from these seeds. This is how and why we continue to have plants in nature. Pollination is an important step in this process. If pollination does not occur, no other subsequent parts of the reproductive cycle will occur.

However, if you’re growing a lemon tree indoors as a hobby, you probably don’t care too much about the entire reproductive cycle, just as long as your tree produces an abundance of juicy, healthy lemons for you to enjoy. Pollination is a critical step in making sure your indoor lemon tree produces fruit. Read on to find out more.

So, How Does Pollination Work?

Pollination happens when the pollen, containing the flower’s sperm, is transferred to the sticky, central stigma, which is the botanical equivalent of an egg.

In nature, pollination usually happens when bees and other insects land on a flower to drink the nectar at the center of the flower, or the stigma. The wings and feet of the insect will brush up against the ends of the surrounding stamens, which contain powdery yellow pollen. The pollen will transfer to the wings and feet of the insect, and when the insect buzzes to another flower on the plant, the pollen will be transferred to the stigma of another flower. If ripe pollen is successfully transferred to the stigma, the bud will become fertile and eventually bear fruit.

Pollination can also happen via the aid of wind, water, and animals. Any activity that might successfully (albeit unknowingly) transfer pollen to stigma helps with this process. This does not always happen within the confines of a single plant or tree. Trees can also cross pollinate each other in nature, and the wind might carry pollen from one tree to another.

In fact, certain species of fruit-bearing trees cannot be pollinated by the pollen from the same tree. Some species of trees produce only male or female acting flowers, and therefore must be fertilized by the pollen of a tree bearing the opposite sex. Luckily, lemon trees are what is called self-pollinating. Lemon trees produce both male and female parts on the same tree, meaning the pollen from the same tree can make the tree fertile and fruit-bearing. You will still need to take some action, however, to help your indoor lemon tree transfer pollen to the stigmas in the absence of bees and other natural forces.

How To Pollinate an Indoor Lemon Tree Manually

There are a couple of ways you can pollinate your indoor lemon tree by hand.

  • The makeup or paint brush method: One easy way to pollinate an indoor lemon tree is by using a makeup brush or a large paint brush. Take either, and gently rub it over each flower. Make sure that the brush is stroking over both the stamens with the yellow pollen and the central, sticky stigma. Rub your brush over as many flowers as are open, transferring a mixture of the yellow pollen from several flowers to the central stigmas.
  • Using a flower: Similarly, you can use a flower as you would a brush. Pick one of the flowers, and rub it against as many of the other open blooms as you can, with the goal of transferring pollen to the stigmas.

It really doesn’t matter which method you choose. The only goal is to transfer ripe pollen to the sticky stigma, so it matters little how you do it. Keep in mind, however, that it is difficult to tell if the pollen from a certain bloom is ripe or not, so it is best to gently rub and transfer between as many different, open flowers as possible for the best chance of fertilization and therefore fruit.

Tip: to increase your chances of fertilization, manually pollinate your lemon tree every few days if there are open blooms.

What to Do if Your Lemon Tree is Not Producing Fruit

Keep in mind that lemon trees need to reach somewhere between 3 and 5 years old before they will begin to bear fruit. At that point you will want to make sure you are hand pollinating your indoor lemon tree using the guidelines above, as your lemon tree needs the process of pollination to produce.

If you are hand-pollinating your lemon tree, and it is over five years old and still not producing fruit, there may be another issue preventing your tree from producing. Circumstances such as a lack of nutrients in the soil, over or under watering, or a lack of enough sunlight can all cause your lemon tree have trouble producing fruit. Bearing fruit is an intensely energy-consumptive process for a plant, and it will need plenty of sunlight, water, and nutrients to do so. Make sure you are watering and fertilizing your tree properly, as it will need this in order to produce fruit. Check for other signs your lemon tree might be struggling and take appropriate action.

See these related articles for more information about watering and fertilizing your lemon tree to optimize its overall health: