Cherry tomatoes are self-pollinating, simplifying their cultivation for home gardeners. Each flower contains both male and female reproductive organs, allowing a single plant to produce fruit. Pollen transfers within the same flower, which is especially beneficial for growing tomatoes in controlled environments or with limited garden space.
Understanding Tomato Pollination
Cherry tomato flowers are “perfect flowers,” possessing both male and female reproductive parts within the same bloom. The male stamens produce pollen, typically fused around the female pistil. For pollination, pollen grains must transfer from the anthers to the stigma.
Once pollen lands on the receptive stigma, it germinates and grows a pollen tube to reach the ovules within the ovary. This fertilization process leads to fruit development. While the flower structure allows for self-pollination, natural vibrations from wind or insects help dislodge pollen from the anthers onto the stigma, enhancing fertilization.
Factors for Successful Pollination
Even though they self-pollinate, several environmental and physiological factors influence cherry tomato fruit set. Temperature is a primary factor, as pollen viability and release are affected by extremes. Optimal temperatures for pollination range from 70 to 85°F (21 to 29°C) during the day and 60 to 70°F (16 to 21°C) at night.
Humidity also plays a role in pollen transfer; an ideal range is between 40% and 70% relative humidity. Low humidity can make pollen too dry to adhere, while high humidity can make it too sticky to shed properly. Additionally, a lack of natural vibrations from wind or insects, especially indoors, can reduce pollen transfer.
Plant health also impacts pollination success. Stress from inadequate water, imbalanced nutrition, pests, or disease can reduce flower production or pollen quality. For instance, excessive nitrogen promotes foliage growth over flower and fruit development. Consistent watering, balanced nutrients, and addressing health issues support robust flowering and improve pollination.
Assisting Pollination
When natural conditions are not ideal or fruit set is low, gardeners can assist cherry tomato pollination. A simple method is gently shaking the plant or tapping flower clusters. This mimics wind or insect vibrations, helping to dislodge pollen within the flowers. This can be done daily, particularly mid-morning when pollen is most viable and dry.
For a more targeted approach, an electric toothbrush or vibrating tool can be used. Touching the vibrating tip to the stem of each flower cluster releases pollen onto the stigma. Alternatively, a small, soft brush or cotton swab can be used for manual hand-pollination. Swirling the brush inside each flower collects pollen, which is then transferred to the stigma.
These manual methods are useful for cherry tomatoes grown indoors, in greenhouses, or areas with limited wind or natural pollinators. Repeating these techniques every two to three days during peak flowering can improve fruit set and lead to an abundant harvest.