Gardenia trees grow wild on the African continent. With the help of birds and animals eating the seed pods, gardenia trees pop up any place where the weather conditions are accommodating to the seeds. Although it is easy for animals to spread the seeds of a gardenia tree in the wild, growing a gardenia tree from a seed is difficult and time consuming for humans.
Description of Gardenia Trees
Gardenia trees can grow up to 15 feet tall when growing in the wild and slightly smaller when cultivated. The leaves of the gardenia tree are glossy, are between 1 to 4 inches long, and are about 2 inches wide at the widest part. Gardenia trees living in the wild have been known to live as long as 65 years. Cultivated gardenia trees live about 15 years.
Description of Seed Pods
Gardenia trees are self-pollinating. Once the flower falls off, the seed pod begins to form. The seed pod generally grows to about 1 to 1-1/2 inches in diameter. It is a green, oval shaped seed pod that develops tiny whitish spots as it matures. The fruit inside the seed pod is yellow and contains up to 600 straw-colored seeds that are about 1/4 inch long.
Preparing the Seeds for Planting
Although it is difficult to separate the seeds from the flesh of the fruit, placing the pulp in a colander and running water over it will help. Once separated, soak the seeds overnight in a jar or bowl and plant any seeds that sink. Seeds that float are less likely to germinate than the seeds that sank to the bottom of the container.
Gardenia tree seeds take from four weeks to three months to germinate. Seeds that have been soaked overnight have a germination rate from 42 percent to 85 percent for fresh seeds. Gardenia tree seeds that have been stored have a germination rate that is much lower than that of fresh seeds.
Planting the Seeds
Gardenia tree seeds should be planted in a mixture containing three parts perlite and one part potting soil or dirt. The seeds should be planted on top of the moistened growing medium. The growing medium should be kept moist until the seeds germinate. Once the seeds germinate, it takes about three years to grow large enough for blooms to form.
Other Propagation Methods
Gardenia tree seeds seldom set seed pods when not grown in the wild. Therefore, cultivated gardenia trees are generally propagated as cuttings or as grafts. Propagating gardenia trees by cuttings or grafting is an easy and much more reliable way to propagate gardenia trees.