NC State Extension

Strawberry Pollination Basics

Strawberry flower morphology and seed set

Strawberry flowers have both male and female parts on each bloom. The male parts include the pollen carrying portion of the flower (highlighted in blue) and pollinators must come into contact with this area to collect pollen grains. The female parts of the flower (highlighted in pink) must individually receive pollen grains to attain complete pollination.

Strawberry flower. Photo: Jeremy Slone

Strawberry flower. Photo: Jeremy Slone

Lack of complete pollination in each pistil (female flower part) can result in smaller or misshapen berries, meaning reduced yield of marketable fruit.

Poorly pollinated berry (left) and a misshapen berry (right). Photo: Jeremy Slone

Poorly pollinated berry (left) and a misshapen berry (right). Photo: Jeremy Slone

The actual berry forms from each pistil developing into an individual “seed’ that is actually an individual fruit, called an achene. The fleshy red part of the strawberry is rather an enlarged receptacle that holds the achenes (Poling, 2012).

Berry development from each pistil being pollinated into individual achenes. Photo: Jeremy Slone

Berry development from each pistil being pollinated into individual achenes. Photo: Jeremy Slone

As seen in the photo below, there are many ways for pollen to be transferred within the flower and unlike some crops, strawberries are self-fertile. However, maximum yields are possible with a combination of self-pollination (pink), wind (blue), and insects (green).Although flowers are capable of self-pollinating, each pistil must receive pollination, and studies have shown that self-pollination and wind-blown pollen are often not sufficient to completely pollinate a flower. Only about 60-70% of maximum pollination results from these vectors alone, and open pollination with the aid of insects is necessary for the greatest yield. Insect pollination can also improve strawberry quality and shape, meaning that berries last longer and look fuller!

Different modes of pollination on each flower. Photo: Jeremy Slone

Different modes of pollination on each flower. Photo: Jeremy Slone

References:

(Written by Jeremy Slone, August 2016)