The path to pollination

The path to pollination

Article originally published by: Kiwi Gardener

Rebecca Lees reveals ways to increase pollination of your favourite fruit trees.

Sitting amongst my blossoming fruit trees listening to the hum of bees is a favourite springtime activity for me. The bees sound happy, ecstatic in fact (and I am too) – they’re carrying out an incredibly important job, without which my trees would bear no fruit. But that’s not all there is to it.

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Top. Crab apple tree in blossom.
Bottom. 'Golden Hornet' crab apple.

Flowers come equipped with male and female elements; anther (male) and stigma (female). For successful pollination of a fruit tree, a pollen grain needs to find its way from the anther of one fruit tree variety to the stigma of another. Usually this pollen needs to come from the same species, but a different variety (apples pollinate different apples; pears pollinate different pears). However, bees don’t necessarily go from tree to tree to tree on each flight, so nature deploys a nifty trick. On collecting nectar and pollen from one tree, bees head back to the hive with their supplies. Within the hive the bees constantly rub up against each other and become covered in pollen from other sources. They then head back out to continue nectar collection and, even if they visit that same tree, pollen from other varieties (which they’re now covered in) is transferred, enabling cross-pollination.

It can be disheartening when trees show a tremendous display of blossom yet produce little or no fruit, but there are ways to help. Some fruit trees act as better pollinators than others, increasing pollination rates and yield of crops. Take the Malus x zumi ‘Golden Hornet’ crab apple for instance. I first heard about this tree from our good friends Robert and Robyn Guyton when visiting their forest garden. Robert raved about his ‘Golden Hornet’ crab apple, and its advantage of plentiful blossoms over a long blooming time. For them, this tree acts as a pollinator for many of their 130 apple trees with differing blossom times. I was so excited I planted one in the centre of our own forest garden. We won’t prune this tree low, instead her branches will reach high and wide in the hope that she enjoys this freedom and thanks us with a large bouquet – as well as apples for jelly and cider!

Some fruit trees grow well in particular regions and others struggle. Apricots, for instance, are difficult to grow here in South Canterbury, due to late frosts. So, when purchasing fruit trees, visit your local garden centre or speak to someone with experience growing in your particular area.

When planting pollinator trees, keep them close to the varieties they are to assist, say within 30m, and plant varieties that bloom in the same season, or have long blooming times such as the ‘Golden Hornet’ crab apple.

There are some things we can’t control with pollination, such as bad weather deterring pollinator insects or frost damaging blossoms, but the great thing is that even with rough weather in spring, it only takes a few days of good weather, at the right time, and those bees (and other insects) work hard pollinating our muchloved fruit trees.

 

Pollination Chart

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Bee pollinating an apple blossom

Apples

Some varieties are self-fertile. Most require other apple varieties to be pollinated.

Apricots

Some are self-fertile. Having other varieties available for pollination produces more reliable (and sometimes better yielding) crops.

Cherry

Best to plant a self-fertile cherry, to assist in pollinating other cherry varieties. They are not usually pollinated by ornamental cherries.

Feijoa

Some are self-fertile. Most require different varieties for pollination and to produce more reliable (and sometimes better yielding) crops.

Figs, nectarines, peaches and citrus

Are usually self-fertile.

Pears

Require a pollinating variety.

Olives

For best results, plant another variety for pollination.