Collecting and planting ginkgo seeds is a reliable way to propagate ginkgo trees. Ginkgo seeds contain toxic chemicals, so one of the most important tips when collecting and planting ginkgo seeds is to wear protective clothing and eyewear. When planting the seeds, depth, soil medium and seedling care are important factors for germination and successful growth.
It is important to wear rubber gloves, protective clothing and protective eyewear when handling and cleaning ginkgo seeds. The seed coat contains butyric and hexanoic acid, two strong acids that burn skin and can damage eyes. It's a good idea to do all the seed preparation outside, too, as the odor has been compared to vomit.
Ginkgo trees produce abundant seeds that ripen in late fall. The seeds can be collected from the ground and placed in a bucket for transportation and washing. They should be washed in fresh cool water, and a scrubbing brush can be used to clean away the outer seed coat. When dumping the water, it is important to deposit it in a spot where people and pets won't inadvertently come into contact with it.
The cleaned ginkgo seeds should be left out to dry in the sun or in a light room for three to four days. The dried seeds can then be packed in damp peat moss and stored in a plastic bag at 60°F (about 15°C) for six weeks, then kept in the refrigerator for two to three months.
After the storage period, ginkgo seeds are ready to plant. A 4-inch (about 10-cm) pot filled with potting soil is ideal. The seeds are planted 1 inch (about 2.5 cm) deep and one seed per pot. Germinating ginkgo seeds in pots allows the grower to closely monitor temperature and moisture levels.
The seeds can also be planted outdoors into a seed or nursery bed in late winter or early spring. When planted in a nursery bed, ginkgo seeds should be spaced 2 inches (about 5 cm) apart. Planting seeds directly outdoors saves space and materials, and is better suited for larger growing operations. Once the seeds germinate and emerge, they can be thinned to a spacing of 8 to 12 inches (about 20 to 30 cm).
Ginkgo seeds typically germinate 15 to 45 days after planting. During germination and the early growth period, it is critical to keep the soil in the pots or nursery beds evenly damp. Potted ginkgo seedlings can be planted out into a nursery bed in spring or early fall.