A while back, an actual astronaut came to my office. He was training here, and must have seen a couple of columns about the soil food web and decided to come in and discuss how to germinate a seed and grow a plant … in space. One problem he faced was that he wasn’t going to be able to bring soil on his trip. We came up with the idea of using diapers as the germinating and then growing medium.
Now, make no bones about it. I am a soil guy and have a trilogy of soil books under my belt as proof. Still, I am always interested in the different things people use instead of soil to germinate seeds or root things. Given the COVID-19 state of things this winter, it might be fun to try them. I am pretty sure NASA hasn’t.
The old standby, of course, is using eggshells to grow plants, though it doesn’t solve the soil problem. This is because people believe egg shells contain some of the essential nutrients necessary for plants to grow. They do: calcium 34%, magnesium 0.3%, phosphorus 0.04% and potassium 0.03%, as well organic matter at 5%. However, if you shift through your compost pile, you will notice that everything has converted to soil except the egg shells. The nutrients in egg shells are locked up until the shell decays. If it were otherwise, we would eat the shells, too. Egg shells make a suitable container for a seed, but not much else.
One of the weirdest things I have seen people use are whole bananas, not that NASA would let one on board. Sometimes it is as a germinating medium. You can stick a large seed, like a marigold, and germinate it. It is not a foolproof method. Better to use a banana peel to grow stag horn ferns. Put behind one, the decaying peel provides nutrients. Bananas work best, however, for rooting cuttings (in particular roses and citrus fruits). The cut ends of cuttings are put into a whole banana, and then the banana is half buried in soil. It takes three or four weeks for roots to develop, which they will because the potassium in the peel is great for root development (necessary, actually). There is not very much nitrogen in a banana peel and lots of potassium. This is actually good for germinating and rooting as nitrogen would promote green growth over root growth.
The same is true of potatoes. Remember your mother telling you to eat their skins because they contain all the nutrients? They are actually chock full of potassium, and this is why they, too, make great cutting media. Stick in a stem and roots grow. Perhaps dehydrated potatoes and bananas would make great soil amendments? I am going to try cut and dried banana peels, too.
On to tomatoes. Ever opened the fridge and see one with seedlings growing out of it? This is called Vivipary. This happens with pears, apples, lemons, papaya, avocado, strawberry (very weird, as each seed germinates into a different plant) and even peaches, with those tough pits! There is enough moisture in these fruits to support germination, but they have to mature enough so the chemicals that actually prevent germination are broken up and are no longer effective. The problem is, you have to get the germinated seedlings to soil or they will die.
While no doubt tomato, potato and bananas, even egg shells would have helped my astronaut somewhat, his diaper was a better choice, because weight is the ultimate consideration when it comes to space. Fortunately, we don’t have restrictions here on Earth, where it is clear that seeds germinate just fine in soil. Still, it is the Time of the Covid, and it might be fun to grow, say, a papaya, with an easy, no-fuss, no-soil way to germinate the seeds.
Jeff’s Alaska garden calendar for the week
Alaska Botanical Garden: All Alaskan businesses need support and The Garden is not an exception. Please join now. Membership makes a great holiday gift, too. Due to the changing nature of things, check alaskabg.org for information on events and hours and classes, some of which are online.
Hoar frost: This stuff can get heavy and damage limbs. Knock it off. Really.
Bird feeding: Bear tracks seen in Oceanview. Just saying, be aware.