May 13, 2020
Definition: Seeds that do not survive freezing and drying during off-site conservation but instead need to be stored at high moisture
levels. Recalcitrant seeds are often referred to as unorthodox seeds and can be characterized by their sensitivity to desiccation, the process of extreme
Forest Garden Fact: Recalcitrant seeds are produced by a few trees that are commonly found in Forest Gardens throughout sub-Saharan Africa, including, jackfruit, lychee, mango, avocado, cacao, and coconut. Other common recalcitrant seeds are rambutan and durian.
Storing Recalcitrant Seeds: Recalcitrant seeds require moisture to remain viable for germination. Unfortunately, maintaining high moisture content also makes them more prone either to germination during storage, or to pest and disease attacks, making storage challenging, but not impossible.
Place seeds within a grain sack or other porous container that allows airflow. According to volume, add 1 part of moist sawdust, charcoal, or peat moss for every 3 parts seed. The storage sack can be left covered or uncovered but should always be kept in dark room, off of the floor. Be sure to check on moisture content and seed conditions twice a week to make sure the seeds retain their moisture and are free of pests and mold. Unlike orthodox seeds, recalcitrant seeds can only be stored for a few weeks to a few months depending on the species.
Storing Orthodox Seeds: Orthodox seeds require different storage conditions than recalcitrant seeds. Before preparing your seeds for storage, it is important to know which seeds have more orthodox or recalcitrant properties so you can store things properly.
Unlike recalcitrant seeds, orthodox seeds can withstand low moisture. In fact, you should dry orthodox seeds well before placing them in containers. Storage containers for orthodox seeds can be made of a variety of materials including plastic, glass, metal, or clay. No matter which container you choose, if you intend to store your seeds for a long time, be sure to use a waterproof, air-tight container that is opaque.
Orthodox seeds should be kept in a cool, dry, and dark place. With the right storage in place, you'll be able to store viable orthodox seeds for several years or even decades!