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GERMINATION OF TROPICAL SEEDS. |
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Sowing of tropical seeds require sometimes special precautions to be successful. Soaking In order to start the germination process, water must reach the interior, embryo + endosperm, (dormant plant + food source) of the plant. Under the right conditions of temperature and air, the food source will start converting carbohydrates into sugars needed by the embryo for growth. The seeds must often be soaked in warm (but not hot) water, from only a few- to as many as 24 hours (e.g. Noni seeds need to be soaked overnight). Sometimes with very hard seeds, hot but never boiling, water can be used. Scarification It can be even necessary to nick the coat (outer shell of the seeds) with a file or to use sandpaper. Sometimes the coat need to be cracked or cut in order to let water in and so enable the embryo to break through the coat (Astrocaryum vulgare, Canna indica). All this is not to say that the seeds will not germinate if these measurements are not taken; it will only take longer (sometimes longer than a year, as is the case with the Astrocaryum vulgare). So it is clear that these extreme hard seeds have a long shelf life! Other steps to be taken Water 
However, keep in mind not to water too much once the seeds are sown, otherwise the possibility of root rot is present.Before sowing, water the seeds starting mixture (or other soil used) thoroughly and let it drain of. Basically the soil should be moist but not wet; make sure that all of the soil is moist and not only the top layer. To avoid evaporation one can place plastic sheet on the top layer but make sure that it is not actually resting on it. The use of special nursery flats with a clear plastic lid is an option. Plant the seeds just under the surface or semi buried. Temperature These are tropical seeds we are talking about and they need tropical conditions to germinate! The soil temperature range should be 80 - 90° F. and there must not be much variation in this. The surrounding air should also be in the mid-seventies. When growing of the seedlings occurs, the temperature can be somewhat lower at about 75° F. during daytime and 60 - 70° F. at night. Soil The best thing to use is soil-less seed starting mixture; they have the best pH, retain water, have good air penetration and are sterile so that the possibility of attracting fungi is minimized. Use special nursery flats with clear plastic lids if possible for the seeds starting mixture. Light If you try to germinate seeds indoors, the use of grow lights can be of tremendous help; start positioning these low (8" above the top layer) and when growing occurs raise the lights accordingly. When grown into small plants, reduce the amount of light to 12 hours a day. Trying to germinate in a shady spot is a good. idea Recalcitrant These are only for very experienced gardener. Some seeds, such as from Bread -, Jack fruit, Cacao and Surinam cherry are recalcitrant. This means that they are viable for a only short period (3 - 6 weeks). They are also difficult to germinate outside their natural habitat. Environment Many seeds from the Amazon rainforest (cacao seeds) need full shade to germinate en preferably an organic soil mix, mimicking their natural habitat. Be patient, when germinating seeds; sometimes it can take many weeks for germination. Of course we cannot guarantee any specific germination rate; however, we will guarantee the freshness of the seeds upon shipment to our customers world wide! |