Ginkgo biloba is often referred to as a living fossil because it is the sole surviving species of its order. Its distinctive fan-shaped leaves and remarkable resilience make it a highly desirable landscape tree, but starting one from seed demands considerable time and dedication. Starting with a seed means the journey to a substantial tree may take several years before significant growth is observed. This guide outlines the sequential steps, from proper seed preparation to early care, maximizing the potential for successful germination and establishment.
Sourcing and Preparing the Seeds
The initial step involves securing viable seeds exclusively from mature female Ginkgo trees. Identifying a female tree is straightforward during the autumn months when they produce their small, yellowish, plum-like fruit. The seeds are encased in a fleshy outer layer known as the sarcotesta, which must be addressed immediately.
The sarcotesta must be meticulously removed before planting. This task is often unpleasant due to the strong, rancid odor caused by butyric acid. The sarcotesta also contains chemical germination inhibitors that prevent the seed from sprouting naturally. Cleaning involves soaking the seeds in water and scrubbing them gently, using gloves, until only the hard, light-colored inner shell remains.
Once thoroughly cleaned, the seeds must undergo cold stratification to break their natural dormancy. This chilling period mimics the cold, moist conditions of winter, signaling to the embryo that spring is approaching. The cleaned seeds are placed in a sealable bag or container with a moist, sterile medium, such as peat moss, vermiculite, or fine sand.
Store the container in a refrigerator at a consistent temperature, ideally between 35 and 40 degrees Fahrenheit (2 to 4 degrees Celsius). This chilling period typically needs to last for a minimum of 60 days, and often up to 90 days, to effectively condition the seed for successful germination.
Planting and Germination
After the required stratification period, the seeds are ready for planting, timed to coincide with the conclusion of the last expected frost, typically in late spring. Selecting the proper container is important because Ginkgo seedlings quickly develop a deep, sensitive taproot. Deep pots, such as root trainers or containers at least six to eight inches deep, are recommended to accommodate this initial growth structure.
The growing medium should be well-draining to prevent waterlogging. A mixture of sandy loam combined with materials like perlite or coarse sand provides the necessary aeration and drainage. Plant the stratified seeds approximately one-half to one inch deep into the prepared medium, ensuring the soil is gently firmed around them after covering.
The planted seeds should be kept consistently moist, but never saturated, and placed in a location that receives bright, indirect sunlight or partial shade. The soil temperature should remain relatively cool, ideally around 60 to 70 degrees Fahrenheit, to encourage healthy root development.
Ginkgo germination can be highly erratic and slow, often taking several weeks or even a few months for the first shoots to emerge. Maintaining consistent moisture and temperature is the most important action while awaiting the appearance of the distinctive, tiny fan-shaped cotyledons.
Early Care and Transplanting
Once the seedling has successfully sprouted, its initial care dictates its long-term health, especially during its first year of life. Young Ginkgo seedlings are vulnerable and thrive best in partial shade during their first growing season, as intense, direct afternoon sun can easily scorch their tender leaves.
Watering must be managed carefully, aiming to keep the soil lightly moist but allowing the top layer to dry slightly between applications. Overwatering is a common mistake that can lead to root rot. Consistent hydration is necessary during prolonged dry spells to support the rapid development of the deep taproot.
Protecting the emerging saplings from pests, such as rodents, is a concern. Simple protective measures, such as placing a wire mesh cage around the container, can shield the delicate plants from physical damage. Environmental extremes, including sudden cold snaps or high winds, should be mitigated by temporary sheltering.
The ideal time for transplanting the young Ginkgo into its permanent outdoor location is after one full growing season, when the plant is dormant. This transplanting is a delicate operation due to the taproot’s susceptibility to damage during movement. Perform the move in late fall after the leaves have dropped or early the following spring before new growth begins.
When transplanting, dig a wide hole to avoid bending or forcing the root ball. Ensure the root flare sits level with the surrounding soil surface. Proper care during this stage ensures the Ginkgo can establish itself and begin its ascent toward becoming a resilient, mature specimen tree.