This guide will teach you how to pollinate indoor plants, including whether you have to pollinate them, and if so, what the best practices are for at-home pollinating.
Background information: What Is Pollination?
Table of Contents
- Do My Indoor Plants Need Pollinating?
- How to Pollinate Indoor Plants
Do My Indoor Plants Need Pollinating?
Most indoor plants don’t need pollinating. For example, most decorative house plants and other greens, like herbs, don’t require pollination.
However, if you’re growing plants indoors as part of a fruit or vegetable garden, then some of your plants may need pollination. First, we’ll go through the plants that don’t need pollinating. Then, we’ll discuss the plants that will need pollination, and how to pollinate those indoor plants.
Self-Pollination vs. Cross-Pollination
Pollination is the transfer of pollen from the male part of a flower, the anther (part of the stamen), to the female part of a flower, the stigma (part of the pistil).
Self-pollination occurs when pollen grains are transferred from male to female parts of the same flower or to another flower on the same plant. On the other hand, cross-pollination is the transfer of pollen grains from a flower on one plant to a flower on a different plant (of the same species).
Cross-pollination always requires the help of an outside force to move pollen from one plant to another. This can include the help of:
- Pollinators like bees or other animals
Self-pollinating plants do not need pollinators to reproduce. However, it’s still important to note that even if the plant is pollinated, a self-pollinating indoor plant may not necessarily grow fruit. For some plants, it can be difficult to maintain the correct conditions indoors for fruit to “set” (when a flower turns into fruit) even if self-pollination is occurring. For example, tomatoes are self-pollinating but require specific temperatures of 65-85 degrees Fahrenheit in order to grow fruit from the flowers.
What Kinds of Indoor Plants Don’t Need Pollination?
Plants that self-pollinate usually have flowers that are small, have little to no odor, and have no nectar. This includes:
These plants require no help pollinating and are thus good options for an indoor garden. However, while not necessary, wind or insects can help improve pollination in self-pollinating plants by encouraging the pollen to loosen from the anther.
Other plants that don’t require pollination at all include many herbs and root vegetables, including:
- Herbs, like mint, oregano, basil, and thyme
- Cauliflower and broccoli
- Garlic and onions
What Kinds of Indoor Plants Need Pollination?
Other types of fruits and vegetables need pollination. This helps the fruit grow and also helps you create seeds you can use to grow more plants.
Many fruits and vegetables need pollination, including but not limited to:
- Squash and gourds
How to Pollinate Indoor Plants
The goal of pollinating plants indoors is to mimic nature. As mentioned above, cross-pollination typically occurs in nature through:
- Wind: Wind carries pollen from one flower to another.
- Insects: The insect lands on a flower and then carries it to another.
- Animals: The animal brushes up against a plant or flower and then carries the pollen to another plant. This typically occurs when animals are grazing.
- Water: Water sometimes carries pollen from one plant to another, especially in the case of aquatic plants. This is less common and will not be helpful in the case of indoor plants.
While animals and insects are a primary method of pollination in the wild, these are usually not an option indoors. Here are a few options for how to pollinate indoor plants.
1. Open the window. Opening a window or turning on a fan lets a breeze inside to transport pollen. While an open window may not be an option during winter months, once it gets warm outside, this can help pollinate your indoor plants. Simply put the plant near the open window for a few hours. In the winter you can turn a fan on instead, but make sure it’s on low and is blowing in only one direction.
It’s best not to leave the plant in direct sunlight for too long, depending on the plant type, as some are sensitive to too much light. It’s also important not to let it get too windy and risk breaking delicate plants.
2. Vibrate the plant. This is a manual method of pollination that requires vibrating or shaking the plant. This will work for plants that have hermaphroditic flowers, flowers with both male and female parts. The goal is to distribute pollen from the anther (male part) to the stamen on the pistil (female part) through vibration or shaking. Plants with hermaphroditic flowers include tomatoes, peppers and eggplants.
The easiest way to do this is to actually gently shake the plant yourself. Simply shake each individual flower, or shake the whole plant.
Another method of pollination-by-vibration is using a vibrating tool. Some tools are made specifically for indoor pollination, such as the Be-the-Bee Pollinator tool. To use this tool, you place the vibrating tool on each flower, letting it shake up and transfer the pollen. You can also use an electric toothbrush to transfer the pollen in a similar way.
3. Hand Pollination. This method is the most time consuming method of pollinating indoor plants but is also one of the more effective methods. The goal of manual pollination is to move pollen from a male flower to a female flower. Simply take a clean cotton swab, swab some pollen from the male flower, and transfer the pollen to the female flower. If possible, it’s best to transfer pollen to unopened female flowers.
Most flowering plants have flowers with both male and female parts (hermaphrodite flowers, described above), so shaking will likely work to transfer pollen. Others have male flowers and female flowers on the same plant, such as corn, squash, pumpkins and melons. These are known as monecious plants. Finally, some plants such as kiwi have male flowers on one plant and female flowers on another. These are known as dioecious plants, and are the most rare. Manual pollination may be most effective for monecious and dioecious plants.
In order to move pollen from a male flower to a female flower, you’ll need to be able to tell the difference between male and female flowers. This can vary by species. Here are a few general tips:
- In monecious plants, male flowers typically appear first.
- Male flowers usually have many stamens, which often look like small brown or orange “rice grains” (the anther) attached to a stem going into the flower (the filament). Pollen is attached to the anther which gives it its color. On the other hand, female flowers have a pistil, a large “stem” from the center of the flower. The pistil is usually only a single color, while the appearance of the stamen may vary due to pollen.
- Male flowers are often smaller than female flowers, because female flowers are larger to support seed development.
It can be very difficult to tell the difference between males and females in some types of flowers, so if you’re unsure, look up a diagram of that specific type of plant.