Beautiful flowers with unusual patterns, or garden vegetables that grow a little bigger than normal, are lasting legacies you can pass on to the gardeners in your family. Using cross-pollination, you can manipulate the genetic traits of plants to get the characteristics you want. The size, quantity and appearance of foliage, flowers and fruit are a few of the characteristics you can manipulate with these techniques.
Healthy plants that are undamaged by insects or diseases are the best stock for cross pollination. When the plants you want to cross-pollinate have flowers that are almost ready to open, you can wrap a twist tie around their stems to mark which blooms will produce seeds carrying the combination of traits that you want.
Plants reproduce by transferring pollen from the male anthers to the female stigma. Anthers are long, tube-like appendages near the center of the flower with an oval lump of pollen at the tip. The stigma is usually a long, vase-shaped appendage in the middle of the flower. Plants with perfect flowers have anthers that grow around a stigma inside each flower. Imperfect flowers have one set of anthers or a stigma in each flower. Plants with imperfect flowers can grow male and female flowers on one plant, or they can grow on separate plants. Composite flowers are actually many smaller flowers that each contain a stigma or anthers clustered together into a single mass that looks like a bloom.
A fine-haired paintbrush that is small enough to fit inside the flowers of your plants is a suitable tool for collecting pollen. The pollen on the tip of the anthers should collect on the bristles when you brush the anther lightly. You can use small glass jars to collect and separate pollen from different plants. If you are cross-breeding more than one or two plants at a time, make sure you keep the pollen in separate labeled jars and dip the brush in rubbing alcohol before you use it to collect pollen from another plant.
If you are pollinating a perfect or composite flower, you will need to remove the anthers from the flowers you are going to pollinate. This prevents the flower from self-fertilizing and ensures that only the pollen you choose reaches the stigma. Remove the anthers from a flower before it has opened. You can open the petals and sever the anthers using a pair of tweezers. Once you have removed the anthers, you can pollinate the stigma with pollen from the plant of your choice.
If you are working with very small flowers, you can use a sewing needle to scrape and transfer pollen. While you are working outdoors, the temperature and humidity can interfere with fertilization. Cross-pollinate outdoors in the morning on dry days when the temperature and humidity levels are relatively mild. After you have cross-pollinated a flower, covering it with a clear plastic bag prevents errant grains of pollen from fertilizing your flower with the wrong pollen.