Why Do Blueberries Need Two Varieties?

The Process of Pollination

• To make fruit, the flowers on a blueberry bush need to be pollinated. Every flower has anthers, which contain pollen. To turn into a fruit, the pollen must move from the anthers to the stigma, where it will then develop into a seed and then into a fruit. Pollen needs help from outside sources to travel from anther to stigma. Blueberries produce the most fruit when they can cross-pollinate with another variety, meaning the pollen from one variety travels to the stigma of another.

Self vs. Cross-Pollination

• Blueberry plants can self-pollinate, according to Gayla Trail, expert gardener and author of "Grow Great Grub." During self-pollination, the pollen travels from the anther of one flower to the stigma of the same flower. Blueberries will produce more and better fruit if they are cross-pollinated, though, according to Trail. During cross-pollination, the pollen travels from the anther of one flower to the stigma of another flower. Bees or the wind can carry the pollen from flower to flower. Growing two varieties of blueberry encourages cross-pollination and boosts yields.

Arranging Your Plants

• Blueberries like the sun, so plant them in an area that gets full sun. Space lowbush varieties at least two feet apart and highbush varieties at least six feet apart. If you are planting in rows, plant one row of one variety of blueberries next to a row of another variety to get the best cross-pollination. It's helpful to plant your blueberries near a beehive to get the best fruit yields and quality, according to Penn State's College of Agricultural Sciences.

Choosing Varieties

• Pick varieties that produce fruit at the same time in the season, so that their pollination schedules will be in sync. Some plants, such as Earliblue and Weymouth, produce fruit early in the production season in Pennsylvania. Both of those are highbush varieties. If you want late season fruit, plant two varieties, such as Coville and Lateblue, that produce fruit later in the summer. The type of variety you can plant and when they will produce fruit is largely determined by your location.