Growing ginkgo from seed connects you to one of the most resilient trees on Earth, a living fossil that has watched continents drift. This species, Ginkgo biloba, survives pollution, drought, and centuries of urban stress, making it a compelling project for the patient gardener. Starting from a fresh seed, you participate in the continuation of a lineage that dates back over 200 million years.
Harvesting and Preparing Ginkgo Seeds
The journey begins with obtaining viable seeds, which are actually fleshy nuts enclosed in a plum-like fruit. If you are harvesting from a local tree, collect the fruits when they turn a soft yellow-green and begin to fall. For stored seeds, ensure they are kept in a cool, dry place to maintain germination potential. The primary challenge for the home propagator is the potent odor released when the fleshy pulp breaks down, so preparation should occur outdoors or in a well-ventilated area.
Cleaning the Seeds
To clean the seeds, rinse the fruits under running water and gently rub the pulp away with your fingers. Some growers prefer to soak the fruits for a day to loosen the flesh before rinsing. Once cleaned, the seeds should be patted dry and stored in a breathable container until you are ready to stratify them. Avoid sealing them in airtight plastic bags, as this can promote mold and ruin the embryos.
Stratification: The Cold Treatment
Ginkgo seeds require a period of cold and moisture to break dormancy, a process known as stratification. Take a container of slightly moist sand, peat, or paper towels and mix the seeds in so they are in contact with the moisture but not sitting in water. Seal this container in a plastic bag and place it in the refrigerator, not the freezer, for approximately 60 to 90 days. Check the mixture periodically to ensure it remains damp but not sour, removing any seeds that show signs of rot.
Sowing the Seeds
After the stratification period, you can sow the ginkgo seeds in individual pots or a seed-starting tray filled with a light, well-draining mix. A blend of potting soil and perlite works well to prevent compaction. Plant the seeds about an inch deep, covering them gently, and water the medium thoroughly. Place the containers in a warm location with bright, indirect light, aiming for a soil temperature between 60 and 70 degrees Fahrenheit to encourage germination.
Germination and Early Care
Patience is required, as ginkgo seeds can take several weeks to sprout, sometimes emerging sporadically over a month. Once the seedlings appear, ensure they receive adequate light to develop sturdy stems; a south-facing window or grow lights can prevent legginess. Keep the soil consistently moist but never waterlogged, as young roots are susceptible to damping off. When the seedlings develop a few leaves and are large enough to handle, they can be transplanted into slightly larger pots to continue their growth.
Transplanting to the Landscape
Before transferring a ginkgo seedling to its permanent location, you must harden it off by acclimating it to outdoor conditions over a week or two. Choose a planting site with full sun and enough space for the mature tree’s broad canopy, as ginkgos can grow 50 to 80 feet tall. They are remarkably adaptable to various soil types, preferring deep, sandy loams but tolerating poor urban soils where other trees struggle.
Long-Term Growth and Maintenance
Young ginkgo trees grow at a moderate pace, adding about one to two feet of height per year under optimal conditions. Pruning is generally unnecessary beyond removing any damaged or crossing branches, and these trees are highly resistant to pests and diseases. Because the female trees produce the smelly fruit, many urban plantings utilize male clones, but your seed-grown tree will be unique, potentially offering interesting genetic variation from the parent.
