Growing ginkgo from seed is a rewarding process that connects you to one of the oldest living tree species on the planet. The ginkgo biloba, often referred to as a living fossil, has remained virtually unchanged for over 200 million years. Cultivating a sapling from a humble seed allows you to witness the complete lifecycle of this resilient and culturally significant tree. Success requires patience, as the journey from seed to a recognizable tree can take many years, but the process is straightforward and accessible to any dedicated gardener.
Understanding Ginkgo Seeds and Their Unique Biology Before planting, it is essential to understand the biology of the ginkgo seed, which is technically a naked seed rather than a true botanical seed enclosed in a fruit. The female trees produce structures that resemble yellow, fleshy apricots, which contain a thin layer of flesh over a hard shell. This fleshy layer emits a strong, unpleasant odor when ripe, similar to rotting fruit, to attract animal dispersers in the wild. For cultivation, you should remove this fleshy coating before planting, as it can inhibit germination and attract pests. The hard shell must be cracked or softened to allow the embryonic shoot to emerge successfully. Stratification: The Critical Cold Treatment
Before planting, it is essential to understand the biology of the ginkgo seed, which is technically a naked seed rather than a true botanical seed enclosed in a fruit. The female trees produce structures that resemble yellow, fleshy apricots, which contain a thin layer of flesh over a hard shell. This fleshy layer emits a strong, unpleasant odor when ripe, similar to rotting fruit, to attract animal dispersers in the wild. For cultivation, you should remove this fleshy coating before planting, as it can inhibit germination and attract pests. The hard shell must be cracked or softened to allow the embryonic shoot to emerge successfully.
Simulating Winter Conditions
Stratification is the most crucial step in ginkgo seed propagation, mimicking the natural winter conditions that break the seed's dormancy. Ginkgo seeds require a period of cold and moist conditions to initiate germination in the spring. You can achieve this by mixing the cleaned seeds with slightly moist sand, peat moss, or vermiculite. Place this mixture in a sealed plastic bag or container and store it in a refrigerator for 60 to 90 days. Check the medium periodically to ensure it remains moist but not waterlogged, as rotting seeds are a common risk during this phase.
Planting and Germination Techniques
Timing and Soil Preparation
After the stratification period, it is time to plant the ginkgo seeds. You can sow them directly into the ground in the spring after the last frost date or start them indoors for better control. Choose a location with full sun and well-draining soil, as ginkgos are remarkably tolerant of urban conditions, including pollution and compacted soil. Plant the seeds approximately one inch deep in the soil, spacing them several inches apart if you are sowing multiple seeds. Keep the soil consistently moist during the germination period, which typically occurs within two to six weeks after removing the seeds from cold storage.
Transplanting and Early Care
Managing Seedlings
Once the seedlings have developed their first set of true leaves and are a few inches tall, they can be transplanted into individual pots or their final permanent location. Ginkgo seedlings have a taproot, which means they do not like to be disturbed frequently, so select your initial planting spot carefully to avoid future root disturbance. Water the young trees deeply but infrequently to encourage deep root growth. Fertilization is generally unnecessary for ginkgos, as they are adapted to survive in nutrient-poor environments, and excess nitrogen can lead to weak, sappy growth.
Identifying Male vs. Female Trees
The Importance of Gender Selection
When growing ginkgo from seed, you should be aware that the seeds are produced only by female trees. If your goal is to harvest the seeds for future propagation, you will eventually need a female specimen. However, many gardeners prefer to plant male trees because the females produce the smelly fruit. Unfortunately, determining the gender of a ginkgo tree requires it to reach maturity, which can take 20 to 50 years. To circumvent this issue, you can purchase named cultivars propagated by cuttings, which guarantees the gender, or accept the natural variance of your seed-grown trees until they flower.
