Some plants die hard. At least that seems to be the lesson learned after moss retrieved from deep within the frozen ground of Antarctica was found to still have life left in it. Following in the footsteps of the discovery by a separate research team of moss revived after spending 4oo years beneath glacial ice, researchers from the British Antarctic Survey and the University of Reading set out to determine the viability of the innards of a moss bank encased in permafrost.
Mosses are ancient plants, predecessors to the more recently evolved (at least on a geological timescale) vascular plants. They produce no flowers or seeds and have no roots. Their leaves carry out photosynthesis – just like other plants – but they also absorb water and nutrients. There are about 12,000 species of mosses found in a wide range of habitats. Because they lack a vascular system, mosses require a damp environment (or at least one that is seasonally damp). While commonly seen growing in shady locations, there are some moss species that thrive in full sun, such as those growing on rocks in alpine environments. Mosses are the dominant vegetation in the polar regions where they can form thick moss banks in which an actively growing layer is underlain with moss that has slowly become incorporated into the permafrost.
The researchers in this study, which was published in the latest issue of Current Biology, took a core sample of a moss bank on Signy Island, Antarctica. The moss bank consisted of a single species – Chorisodontium aciphyllum. The sample core went 138 centimeters (4.5 feet) deep, and radio carbon dating of material taken from near the bottom of the core gave it an age of between 1533-1697 years old. The core was cut into several sections and then exposed to temperature and light conditions similar to the moss’s native environment. New growth occurred in many of the sections, but the most impressive finding was that after only 22 days, growth was noted in the 121-138 cm section, demonstrating that even after being frozen for more than 1500 years the moss was still alive. It was simply in a cryptobiotic state – a state in which all metabolic processes pause due to adverse environmental conditions.
Signy Research Station on Signy Island (photo credit: Wikimedia Commons)
Certain microbial life has been known to survive in a cryptobiotic state for tens of thousands of years, however this is the first time that a multicellular organism has been found to survive in such a state for longer than a few decades. So is their a moss species out there that has been surviving frozen conditions for even longer? It’s quite possible. And from an ecological standpoint, suspended animation is essential in order for polar mosses to survive periodic ice ages. Perhaps that’s why they have developed this remarkable trait.
Read more about this study here and here.
Last month on Ken Druse Real Dirt podcast, Druse talked to Ken Greene, the founder of Hudson Valley Seed Library. Greene came up with the idea for a seed library while working as a public librarian. The concept: people check out seeds from the library, they plant those seeds in their gardens, they save some of the seeds from the plants they’ve grown, and then they return the saved seeds to the library, at which point the seeds are available for someone else to check out and do the same. Greene started his seed library at the public library where he worked. He soon discovered the great need for educating the public about seed saving, and so he quit his day job and founded his own seed company. Along with carrying on Greene’s original vision of a seed library, Hudson Valley Seed Library is a producer and distributor of seeds, as well as a great resource for information concerning seed saving and other farm and garden related topics (just check out their blog to see proof of this).
Castor Bean Seeds (Ricinus communis)
When Greene first started his seed library, there were very few others. But the idea is catching on. Perhaps you have one in your region. My local seed library is called Common Wealth Seed Library. And speaking of local, in the interview with Druse, Greene talks about local seed growers. They used to be common, but many were bought up by larger companies. However, they are making a comeback. My local seed grower is called Earthly Delights Farm. Local seed growers are worth supporting because the seeds they offer have been produced in that particular region. Ideally, they are varieties that have been trialed against similar varieties and selected for their superiority. This means that the selected varieties are likely to do well in that region.
Expect more posts about seeds, seed saving, and seed banking in the future. In the meantime, share your thoughts about anything seed-wise in the comment section below.
I overwintered some lettuce, and so can you. Below freezing temperatures usually mean the end of the growing season for most things, but certainly not for everything. The truth is that salad greens (lettuce, spinach, kale, etc.) can be overwintered, especially if you grow them under a cold frame or hoop house or in an otherwise protected location. Some can even be harvested throughout the winter if the conditions are right.
Last fall I had nine lettuce seedlings that I had started indoors. I transplanted them outside in either late October or early November (memory isn’t serving me right now). I placed some straw mulch around them, and then covered them with a makeshift cold frame made out of PVC pipe and floating row cover. There they remained all winter long.
I live in Boise, Idaho. The winters here are relatively mild (compared to the rest of Idaho), but we still have plenty of days with below freezing temperatures. Our frost-free growing season is about 160 days long. The average low temperature from December through February is around 25° F. This past winter, our lowest temperature (according to Weather Underground) was -7° F, and we had at least 30 days in which the low temperature reached 20° F or lower. Needless to say, it was a chilly winter.
But my lettuces held on…at least most of them. When I uncovered my cold frame in early March, I found that six of my nine lettuce seedlings had survived. It didn’t surprise me that a few had perished – some of the seedlings that I had transplanted were quite small, and I had serious doubts that they would make it. I was satisfied to see that the majority of them were still alive. Two-thirds ain’t all that bad.
The varieties that I planted were “Freckles” and “Winter Density.” I chose these because the descriptions I read gave me the impression that they were ideal for overwintering. But descriptions be damned. I suggest seeing for yourself. Take any variety of lettuce or other salad green and experiment in your own garden. See what you can get to overwinter with or without protection. Seeds are fairly inexpensive, and it is worth seeing what you can get to survive through the winter. Differing climates – both macro and micro – will produce varied results, and every year things will be a little different. This is one of the many joys of gardening. Weather and climate will always be factors, but they can also be markers to help us see what we can get away with. And if one of the things you get away with is getting lettuce to survive a harsh winter, it means you will be eating garden fresh lettuce long before your neighbor.
Last week I attended a workshop at the University of California Botanical Garden at Berkeley. Apart from receiving valuable training on how to monitor for and report plant pests and diseases in a public garden setting, I also had a chance to explore the garden. UC Berkeley’s botanical garden is located in Strawberry Canyon in the Berkeley Hills. It covers 34 acres and features plant collections from around the world, including South Africa, Asia, Australia, New Zealand, the Mediterranean, and the Americas. Most of the plants were collected from the wild or cultivated from wild collected plants, and a large number of them are rare or endangered species. I was very impressed with how beautifully designed the various gardens are, each display loaded with hundreds of different plant species all meticulously labeled. Because the garden is located in a canyon, the majority of the beds are on slopes, so there has been lots of great rock work and terracing done to create them, and there are numerous side paths that take you off the main path and up into the gardens, giving you the feeling that you are exploring a natural area. Also impressive is the garden’s focus on plant conservation. If you ever find yourself in the San Francisco Bay area, I highly recommend spending some time at this garden. With any luck, I’ll make it back there again someday. The limited time I had to spend there certainly wasn’t enough to explore it fully.
Southern African Collection
New World Desert Collection
Mexico/Central America Collection
Alabama Snow-Wreath (Neviusia alabamensis) from Alabama, USA
Lilac Verbena (Verbena lilacina) from Mexico
Spiral Aloe (Aloe polyphylla) from South Africa
Agave victoriae-reginae) from Mexico