Understanding Pollination
Pollination is the transfer of pollen that allows many flowering plants to produce seeds and fruit. Understanding pollination helps gardeners diagnose situations where plants flower but produce little or no fruit.
What Pollination Does
Pollen must reach the appropriate part of a flower. Successful pollination can lead to fertilization and subsequent seed or fruit development.
Self-Pollinating Plants
Some plants can pollinate using pollen from the same plant. Even these plants may benefit from movement caused by wind or insects.
Cross-Pollination
Other plants require or benefit from pollen being transferred between different plants. Pollinators can be especially important for these crops.
Wind and Insects
Some plants rely primarily on wind, while many flowering vegetables and fruits depend on insects.
Flowers Without Fruit
Poor fruit set can result from insufficient pollination, unsuitable temperatures, plant stress, inadequate nutrition, or other factors.
Encouraging Pollination
Provide suitable flowering plants and avoid unnecessary pesticide applications that can harm pollinators. Maintain healthy plants so they can produce viable flowers.
Hand Pollination
Some crops can be hand-pollinated when natural pollination is inadequate. The exact technique varies by crop.
Flower Structure Matters
Flowers contain reproductive structures that produce and receive pollen. The exact arrangement differs among plant species.
A plant may have flowers containing both male and female structures, separate male and female flowers on the same plant, or male and female flowers on different plants.
Why Pollination Can Fail
Poor fruit set may result from:
- Lack of pollinator activity
- Extreme heat or cold
- Rain interfering with insect activity
- Poor plant health
- Inadequate flowering
- Timing differences between pollen and receptive flowers
Do not assume every failure is caused by a lack of bees.
Encourage Pollinators
Provide diverse flowering plants, avoid unnecessary insecticide applications, and provide suitable habitat.
A vegetable garden surrounded by a variety of flowering plants can offer more resources than a garden containing only vegetables.
Hand Pollination
Some crops can be hand-pollinated by transferring pollen between appropriate flower structures. Timing is important because flowers may be receptive for only a limited period.
Diagnosing Fruit-Set Problems
Record when flowers appear and when fruit begins to develop. Compare healthy and affected plants.
If the problem occurs across the entire garden during a period of extreme weather, environmental conditions may be more important than pollinator numbers.
Conclusion
Understanding Pollination is a skill that becomes easier with practice. Use the principles in this guide as a foundation, observe how they apply in your own garden, and adjust your approach as you gain experience.