Pollination is one of the most fascinating and vital processes in the fruit grower’s toolkit. Without it, no matter how healthy our plants or how fertile our soil, we’re left with blossoms and disappointment. Whether you’re growing apples or aubergines, strawberries or sweetcorn, pollination determines whether flowers become food.
For the most part we can leave nature alone and enjoy success, but when we grow early crops, in a greenhouse, polytunnel, or low tunnel sometimes we need to give nature a helping hand. Also when selecting varieties to grow, it’s useful to understand how our choices can improve our chances of success.
In this chapter, we’ll explore the different types and mechanisms of pollination, how environmental factors influence success, and what practical steps you can take to maximise fruit set. We’ll illustrate each principle with real examples from a wide range of common fruits and vegetables, most of which you might already be growing.
Pollination is the process by which pollen, containing the male reproductive cells of a plant, is transferred to the stigma, the receptive part of the female organ. If successful, fertilisation occurs and fruit begins to develop.
For some crops, this transfer happens within the same flower. For others, it requires pollen from a different flower—or even a different plant.
The pollination process hinges on two main factors:
These plants can produce fruit with their own pollen. The male and female organs are either in the same flower (hermaphroditic or perfect flowers), or at least on the same plant. Tomatoes, peppers, aubergines, and strawberries all fall into this category.
But self-fertile doesn’t mean independent. Most still benefit significantly from external help—especially insects or gentle vibration—to move pollen effectively. For example, indoor bush tomatoes can fruit on their own, but tapping the flower trusses or using a toothbrush to simulate bee vibration can drastically increase yields. Personally I prefer just brushing the leaves of the plants with my hand as I walk past a few times a day, especially for early greenhouse crops.
Self-sterile (or cross-pollinating) crops need pollen from a genetically distinct individual of the same species. Apples, pears, sweet cherries, and many plums are classic examples.
For example, a Rainier cherry tree cannot pollinate itself. It needs a compatible partner like ‘Van’ or ‘Stella’ flowering at the same time. Even some partially self-fertile plums like ‘Victoria’ crop more reliably with a friend nearby—such as ‘Opal’ or ‘Blue Tit’.
Monoecious plants have separate male and female flowers on the same plant. These include all the squashes and gourds—courgettes, summer squash, winter squash, melons, and cucumbers (unless they are all female varieties | which I grow ).
In these cases, insects—mainly bees—are essential to transfer pollen from the male to the female flowers. A lack of pollinators (or a surplus of male-only early flowers) can lead to fruitless plants unless you intervene with hand pollination.
Less common in home gardens, dioecious plants like kiwifruit have male and female flowers on separate plants. You’ll need one male for every six or so females.