The optimal period for propagating black alder is during autumn, leveraging the cutting method. This season provides mild temperatures and adequate light levels conducive to root development. Autumn propagation aligns with black alder's growth cycle, allowing cuttings to establish roots before winter dormancy, ensuring a robust start in the following spring. Reliable sources recommend this period for cuttings to maximize success rates.

After roots have established, gradually acclimate the black alder to outdoor conditions by providing some direct sunlight and exposing it to the elements for longer periods each day. When the plant shows new growth, transplant it into its final growing location with full sun or partial shade. Black alder enjoys moist soil, so ensure that the site does not dry out completely. As a riparian species, black alder can tolerate, and often thrives in, wet soil conditions and can also improve soil quality by fixing nitrogen through its root nodules.