Germinating Recalcitrant Seeds
Prepare some clean (without organic debris or mold spots) dry sphagnum moss and soak it entirely in water. You may need to adjust PH of your water depending on your acidity level and plants being grown, but we use tap water without thought. Take the soaked sphagnum moss and squeeze all the water you can in a few second tight fist. Loosen the moss back up, fluff it up, and place it into a bowl with a lid. Use about a 2-4cm layer of moistened moss on the bottom of the bowl or container, depending on the physical size of your seeds.
Place the seeds on top of the bottom layer of sphagnum moss with the "eye" facing down. No need to pat them down, just leave it all very loose. Avoid having the seeds touching each other or the walls/bottom of the container to avoid any wet spots.
Again depending on the size of the seeds, place a 2-4cm layer of more moistened moss on top of the seeds. More layers of seeds can be placed on top, or multiple containers may be used. Note that stacking layers of seeds in one container may make separating them later on, when they are to be transplanted to soil, more difficult.
We often place lids on these containers and fan them 2-3 times daily, but this depends on the species. Sometimes jars without lids are also used with great success, it mostly depends on the species' dehydration risk.
Species we use this method for
Annona sp. - Sugar Apple We use this for many Annona, but it is not usually required.
Artocarpus sp. - Jackfruit, all.
Baccaurea sp. - Tropical Bornean species.
Durio sp. - Durian species, all.
Euphoria longan - Longan
Garcinia sp. - Mangosteen and other Garcinia
Litchi chinensis - Lychee
Mangifera indica - Mango, with and without seed coat
Pachira sp. - Malabar Chestnut
Pouteria sp. - Abiu, Canistel
Rollinia sp. - Biriba
Salacca zalacca - Snakeskin Fruit
Sandoricum koetjape - Santol
Synsepalum dulcificum - Miracle Fruit
Syzygium sp. - Wax Apple, and others
Theobroma sp. - Cacao