The Difference Between Self-Pollination & Cross-Pollination

Self-Pollination

• Self-pollination is a process in which a plant produces its own pollen for fertilization. Male flowers on the self-pollinating plant produce pollen that is carried by a pollinator, sometimes by animals such as bees or butterflies and sometimes by the wind, to a female flower on the same plant. Sometimes the flowers have both sexual organs and can be self-pollinated on the very same flower. Self-pollination may also refer to exchange of pollen between two nearby plants of the same cultivar.

Cross-Pollination

• Cross-pollination happens when a pollinator, either an animal such as bees or butterflies or another non-animal pollinator, carries the pollen from one cultivar to another cultivar nearby to fertilize the ovule and produce a new plant. Cross-pollination can only work when the two plants are compatible. For example, pollen from one Jonathan apple tree will not fertilize the flowers of another Jonathan apple tree. Many fruit trees require two specific compatible cultivars to create the new fruit.

Cross-Pollination Limitations

• Aside from the compatible cultivars issue, cross-pollination has other challenges. Only the randomness of nature or careful planning will produce some cross-pollinated species. The two compatible cultivars must be within a close proximity of one another to make the pollination possible through natural means. They generally need to be within 100 to 200 feet of one another to give the pollinating bees or other pollinators a chance to reach them with the pollen still attached. Also, the two cultivars must be in bloom at the same time, since without the flowers in bloom, most plants cannot carry out reproduction. There are ways to manually fertilize the plants in a controlled environment.

Advantages of Each

• Both self-pollination and cross-pollination have their advantages. A self-pollinating plant may be able to reproduce even when there are no pollinating animals present. The simple shake of the stems on flowers caused by the wind may be enough to knock pollen into the female flowers and complete the process. Meanwhile, cross-pollinated plants enjoy greater genetic diversity, which can increase plant health and production of better fruits.