Cross-Pollinating Trees

If you’re new to planting fruit trees, you may have been surprised to learn that many varieties are not able to fruit without cross-pollination, meaning you will need multiple plants to produce fruit.

What is Cross-Pollination?

Cross-pollination is defined as when the pollen of one plant is used to pollinate another plant. The vast majority of plants are endowed with both male and female reproductive organs. However, not all of them are self-fertile, meaning that although they have both male and female parts, they cannot produce viable seeds unless another plant of the same species is within close enough proximity for the pollen to be carried by wind or pollinator to that plant. In these instances, cross-pollination is required in order for fruit to be produced.

Can Cross-Pollination Be Used to Create Hybrid Plant Varieties?

Cross-pollination can result in hybrid varieties, whether intentionally or accidentally. Regardless of intentionality, though, the creation of such hybrids may be important in the development of new and improved plant varieties that are armed with desirable traits. This method can be used to tend to customer preferences (for example, bigger, sweeter varieties) or to improve the health and longevity of a species (for example, improved disease resistance).

Are Different Tree Species Required for Successful Cross-Pollination?

In some instances, the same species is required, and in other instances, plants will cross-pollinate with a different species within the same genera. There are also plants that are simply particular. Many varieties of elderberry, plums, and apricots, for example, are capable of self-fruiting, but the yield will be minimal without another variety nearby.

What to Consider When Choosing Plant Varieties for Cross-Pollination:

Cultivar/Compatibility.
Some plants are only able to be cross-pollinated by certain varieties of the same genera, whereas others need to be cross-pollinated by a different plant within the same species. In most instances, your local nursery will have a pollination chart for fruit tree varieties they carry. Another way to determine tree compatibility is to look at a trusted online source, like Universities. Washington State University has some great information for cherry, pear, and apple trees. It’s always a good idea to consider your options prior to purchase.

Flowering Timing.
Pollination will only be made possible if both male and female reproductive organs are receptive. This means they both need to be in bloom at the same time. If they aren’t, the transfer of pollen will not happen naturally. That said, hand pollination is an option. If the flowers from one plant enter their flowering phase prior to the other plant, it is possible to carefully collect and preserve the pollen until the second plant has gone to bloom.