Propagation by Seeds
The fleshy fruits of Santalum freycinetianum are oval with a distinct ring at the end. They range in size from 3/8 to 5/8 inch long, are reddish purple to black when ripe, and contain a single seed.
The seeds need to be removed from the fruit pulp. Lilleeng-Rosenberger (1998) and Stratton et al recommend ripening the fruits in a plastic bag. This softens the pulp making the seeds easier to clean. After softening, the fruit flesh can be removed by either placing the fruits in a colander or strainer under running water, or breaking up the fruit by hand in a bowl of water. The lighter pulp will float and can be poured off. The seeds should then be washed thoroughly and air dried on a paper towel.
Best results are obtained with fresh seed. Before planting, soak the seeds in room temperature water for 24 hours. Discard any seeds that float. The seeds rot easily and Stratton recommends soaking the seeds for 5 minutes in fungicide and then air drying them.
Santalum freycinetianum is difficult to propagate from seed. Generally, only a few seeds will sprout and these take a long time to germinate. Stratton et al give germination times of 1 month to 1 year with germination rates ranging from 10 to 50%. Lilleeng-Rosenberger' notes (1996) document a germination time of 3 months with a 30% germination rate for fresh seed that was soaked in room temperature water for 24 hours.
The treatment described by Koebele, on the other hand, results in 90% germination rate for fresh seed and has good results even for 7 month old seeds. In this process, the seeds are removed from the fruit as described above and air dried for about 1 week. After this, a small portion of the seed coat is removed from the pointed end of the seed. Koebele recommends a forceps or medium grit sandpaper for this process. The embryo should be visible in the area where the seed coat has been removed, but care should be taken not to damage the embryo. These seeds are then soaked in 0.05% giberellic acid (GA) in a shallow container for five days. The GA solution should be changed daily. After the seeds are removed from the GA solution, they should be dusted with a 1 to 1 mixture of powdered sulfur and Captan to inhibit fungal infection.
Koebele recommends planting the treated seeds in a covered tray in sterile (unused) moist vermiculite. The seeds will germinate in 1 to 3 weeks. When the root emerges from the seed, it should be planted in a small container in a 1 to 1 mixture of fine cinder (not black sand) and vermiculite.
Other sources recommend planting the seeds in shallow containers in a well-draining mix such as 3 parts #2 perlite to 1 part Sunshine Mix #4. The medium should be kept moist and the containers put in a shaded, covered area until germination. The cover will allow better control of soil moisture and prevent rain damage.
If it is necessary to store the seed, put the cleaned, air dried seed into a paper bag or envelope inside an airtight container with dessicant. The container should be stored in a cool place at 25% relative humidity. (Bornhorst 1996; Koebele 1999; Lilleeng-Rosenberger 1996; Lilleeng-Rosenberger 1998; Stratton 1998; Wagner 1990)