Germinating Palm SeedsA Primer
Many who get bitten by the palm bug also get hooked on germination. The most difficult part of growing palm from seed is finding the patience. But if you’ve been growing palms, you have hopefully located some of that already.You can always generate a lively discussion by asking some veteran germinators what is the best way to sprout seeds. And you will get as many recommendations and suggestions as those answering. While there are several differing techniques that will yield adequate results, there are some common themes and conditions that most germinators strive to achieve. It’s how they go about achieving these conditions where the differences lie.
Most everyone seems to agree that the freshest, most mature seed is the best. Some palm fruit is bright red when ripe. Some are purple, some orange, some black, and at least one is white. Generally, the deeper the ultimate color the better, but not always. If you are collecting the seed yourself, it would be wise to know what the seed should look like when mature. It is commonly believed that the smaller tropical seeds loose their viability the quickest. However, it has been observed that when proper care is taken to keep them clean, out of the direct sun, high heat, and never allowed to dry completely, the viability is markedly extended. If collecting seed in the tropics, and away from air conditioning and clean water, it can be difficult to take the special care needed. When you buy or are given seed, there are ways to check if they are still good. If you can spare a seed, cut into it. Palm seeds are either homogeneous or ruminate. If homogeneous the endosperm should be white and intact like fresh coconut meat. If it is mushy, off color, or smelly, it is not worth the time or trouble. You may also run the risk of introducing pathogens to your germination process. Only if the seed is rare would the risk be worth the reward. Ruminate seed may be a little harder for the untrained eye to detect viability due to the more complex appearance of it’s endosperm. The float test can also be helpful in evaluating the quality of your seed. If after soaking the seed for 24 hrs, in preparation for “planting” (to be discussed later) most good seed will sink. As with the other advice offered here, there are always exceptions. For example, several palm seeds like Manicaria and Metroxylon vitiense, have developed a floating trait to help with seed dispersal. Use your senses, as you would with any fruit or nut, to help determine freshness.
Most times you will not have any control over the seed you acquire. In these cases, you will just have to do your best to prepare the seed for germination as quickly and carefully as possible. If you have acquired seed with the fruit pulp or seed coat still intact, the good news is you probably have fairly fresh seed. The bad news is most experienced growers recommend cleaning the seeds of this fleshy or fibrous material. This can be a very laborious process, and most likely why a lot of people don’t bother when starting with large numbers of easy to acquire seeds. There are many techniques to cleaning seed. The most popular begins with soaking the seeds until the pulp softens and is more easily removed. This can be accomplished in 48-72 hours remembering to change the water at least daily. If the fruit is very fresh and firm, allowing them to ripen in an enclosed bag in a warm area will soften them up. The soft flesh can then be removed by hand with a mildly abrasive pot scrubber, window screen, or the like. If very soft, a plastic jar filled with sharp rocks and water, and vigorously shaken will remove the pulp. The same principal has been used with rock tumblers or even cement mixers for large quantities. However you manage, it is worth the trouble, but will be the least enjoyable of an otherwise very rewarding endeavor. Cleaning seeds is one step in the all important process of keeping everything as sanitary as possible. The bane of those who germinate palms are molds, fungi, and insects, all of which come hitch hiking in the fruity pulp of the seeds. But even if your seeds arrived already cleaned, all of those bad things can hide inside the seed thanks to burrowing insects. That is why it is also recommended by many (but not all) to use a 5% bleach, or mild insecticidal soak for 15-30 minutes depending on the size and shell thickness of the seed. A thorough fresh water rinse should follow. One must remain vigilant in protected your sprouting seeds from any of these killers. One “infected” seed can ruin the whole batch. More on this will be following. It should also be noted that vigorous cleaning techniques and the use of chemicals should be done with care. It should be realized that what might have worked very well for one species, might damage another.
The planting medium is probably the most varied, yet crucial, aspect of the germination process. Like a French chef, veteran germinators have their own recipes. And the type and consistency of the mix will vary depending on which species is being germinated, and which method is being used. However, some common attributes any successful mix will share are as follows:
- 1) As clean and free of bacteria, fungi, and molds as possible. It can’t be too clean. Sterile would be best, but unachievable. Some germinators will microwave their mix to kill as many pathogens as possible.
- 2) Open and “fluffy” is good. Allowing for air pockets in the mix is important. Until the roots start growing, having soil is not a priority. That is why some germinators will just use damp loose moss as their “mix.”
- 3) Adequate moisture is , of course, crucial. Yet too much can be lethal while promoting rot. This is why having an open mix is so important.
Some of the more popular germination techniques involve a “closed system” that retains moisture. The baggie and Tupperware techniques are two of these. This allows for a constant damp environment without having to worry about the mix drying out too quickly. However in such an environment, cleanliness, an open mix, and monitoring for excess moisture are critical. In such situations, many feel fungicides are a helpful addition, and logic would dictate the longer the germination time, the more helpful a fungicide would be.
Providing your seeds with a nice “Goldilocks” temperature is not only important to get your seeds to sprout, it also plays an important role in how long it will take them to sprout. It is generally agreed that a temperature between 26-35 degrees Centigrade is optimum. However there are many ways to achieve such temperatures. Germinators have been known to place bags or trays of seeds above refrigerators, on top of water heaters, or in the attic, or placed in containers such as ice chests or aquariums with a small night light enclosed. They have used electric blankets or water bed heaters. And there is professional equipment for providing safe, thermostatically controlled bottom heat. It is important to keep in mind that using lights or heaters in enclosed spaces with a moist environment can be dangerous, especially if used in a living area.
There are just too many special considerations to cover in a short article such as this. Some species, like Borassus will require very deep pots to complete their germination process. Other species may be aided by scoring or completely removing the hard outer shell. Perhaps other germinators could contribute to this article by using the discussion tab at the top, and we could begin to establish a useful data base for tricks and techniques for individual species.