Cultivation of Colombian Magnolias at Reserva Natural "El Refugio"
Flower of Magnolia hernandezii at El Refugio (flower is about 20 cm across).
This tree was planted 16 years ago. It was received as a donation from "Jardín Botánico del Quindío".
A group of seedlings has been taken out of the humid chamber and have been planted into individual bags.
Seedling, after germination in a humid chamber
Detail of a seedling (upper view)
Normal seedlings, from fully mature seeds, after germination within a humid chamber
Newborn seedling, brought to light by "Caesarean section" (protective layers of integument were carefully withdrawn, in order to free the cotyledons). This procedure was necessary because the seed, after germination, failed to get rid of the protective layers (this may happen, when seeds are not fully ripe).
Remains of endosperm (white tissue) and part of the integument (soft layer around seedling neck) are still visible.
Group of seedlings beginning to develop their central buds
One-year-old sapling, from the same batch shown above
Very young seedlings
One-year-old sapling (from the same batch shown above)
Three-year-old juvenile, obtained from CORANTIOQUIA ("Corporación Autónoma Regional del Centro de Antioquia") as a small sapling
Our method for bringing Magnolia seeds to germination:
We are currently using plastic pots 20-35 cm across, filled with washed river sand; clean seeds are placed on top of the sand and covered with a 1 cm deep layer of invertebrate-free nursery peat. A stick in the middle of the pot serves to hold a plastic tent that keeps a humid atmosphere, necessary for germination. Such chambers are kept under subdued light, and germination occurrs after two months. Seedlings are taken out of the humid chamber, as soon as they get rid of the seed cover.
Previously, we clean the seeds this way: after soaking them for 10 minutes in a solution of 10% vinegar, we use our fingernails to scratch away the sarcotesta (the red skin surrounding the mature seeds), and finally we brush the seeds clean (using a toothbrush soaked with the same vinegar solution). With this procedure, we intend to imitate the passage of the seeds through a bird's gizzard (birds are the natural dispersers of magnolia seeds).
This method is a simplified adaptation of the germination protocol suggested by Ruiz-Penagos et al. (2012)1
ACKNOWLEDGEMENTS: To the family Calderón-Sáenz, for letting use “El Refugio” as a place for conservation of Colombian threatened plant species. To Dr. Med. Weerakit Harnpariphan, from Thailand, for his support and advise in the propagation of magnolias. To the botanic gardens of Risaralda, Quindío, Medellín and Bogotá for sharing their expertise and plant material. To the people assisting me during field trips.
1 Ruiz Penagos, D., García Sierra, J.H. & Ospina Medina N.E. 2012. Conservación de la Familia Magnoliaceae en Risaralda, Colombia. Universidad Tecnológica de Pereira y Botanic Gardens Conservation International. Pereira, Colombia. 20 p.