Carol McPherson, North Carolina State Extension Master Gardener
I’m a North Carolina State Extension Master Gardener Intern Volunteer from Orange County, North Carolina. When I moved to Hillsborough five years ago, I went to the local nursery to buy a ginkgo tree, which I’d always longed to have. The saleswoman talked me out of it, saying that they were very slow-growing and pointing out the sparseness of the branches on the young trees in stock. How I wish now that I hadn’t been so easily dissuaded for there is literally no tree on earth with the history and characteristics of the gingko tree.
The word ginkgo comes from the Chinese word ‘xinying’ meaning silver apricot. This refers to the fruit of the female tree, not technically a ‘fruit’ in the botanical sense, by the way, but I’ll use that word today. It’s also called the maidenhair tree because its leaves are similar in shape to those of maidenhair ferns. Less flattering names are the ‘stinkbomb’ tree and adjectives such as “disgusting,” and “repulsive,” are used. But more about that later.
In the botanical world, there are only five living groups of seed plants, and ginkgo is one of them. And ginkgo is the only one that consists of only one species. It is utterly unique, not very obviously related to any living plant, but actually more similar to pines than to maples or oaks. Technically, the ginkgo is a gymnosperm, which means that that the seeds are naked—i.e., they are not enclosed within an ovary. Gymnosperm seeds generally develop on the surface of a scale or leaf, or they are modified to form cones. In the ginkgo, they develop on short stalks, each supporting a pair of tiny green orbs called ovules.
The Thrilling Reproductive Cycle of Ginkgoes
It is the reproductive cycle of ginkgo trees that is especially thrilling. Think about a tree being fertilized by swimming sperm… now how unusual is THAT?
I’m going to borrow some descriptions here from Nancy Ross Hugo, author of Seeing Trees. She describes how each of the two tiny ovules secretes a droplet of sticky fluid that sits on the surface, grabs the pollen as it floats by on the breeze, and brings it into the female cells. Nothing happens for a couple of months—the pollen is carefully stored within the female tissue. When the time for fertilization arrives, the ovules grow a pollen chamber and fill it with fluid. The pollen grain then extends a tube into that chamber and releases two swimming sperm cells (complete with 1000 flagella) into the fluid. The sperm cells swim toward the narrow entrance to the egg cells, and may the best man win—only one makes its way through the portal, where it fuses with the egg and fertilizes it. The author notes that you can actually see a YouTube video of this primordial pulsing of the ginkgo sperm in the pollen chamber. I was able to find it quite easily online and you could clearly see the whirlpools created by the swimming sperm. Among woody trees, only the tropical, ancient cycads are fertilized by swimming sperm. Interestingly enough, this fertilization miracle may also occur within unripe fruit that has fallen to the ground, so don’t be too quick to kick aside any fruits littering the sidewalk.
Speaking of ginkgo fruits littering the sidewalk, now we come to the origin of the ginkgo’s nickname, the stinkbomb tree. When the female fruits begin to decay, they are remarkably stinky. Some people compare the smell to rancid butter, but the fruits contain large amounts of butyric acid, which is the primary unpleasant odor of vomit. Virtually no animal today eats the rotting fruit, but it is likely that in the Jurassic period, carrion-eating dinosaurs probably helped to distribute the seeds. Because of the unpleasant odor, most nurseries will only sell and plant male trees. But that, too, has some disadvantages. The pollen from male gingko trees is highly allergenic, rating a 7 out of 10 on the allergy rating scale. Female trees do not produce pollen. Also, planting only male trees means that all the trees are cloned, thus reducing the genetic diversity that keeps a species healthy and resilient.
Ginkgoes can grow to be quite large, normally reaching an adult height of (65–100 feet). The tree has an angular crown and long, somewhat erratic branches. The leaves are unmistakable—they are shaped like a fan and somewhat leathery. Even the vein structure in the leaves is unlike any other tree. Two parallel veins enter each blade from the point of attachment of the long leafstalk and fork repeatedly in two toward the leaf edges. Most leaves are divided into two lobes by a central notch, thus the name “biloba”. The autumn foliage of gingkos can take your breath away. In mid-October an entire tree will go from green to gold in a day or two. And again, in mid-November, the tree will drop all its leaves in a single day! I’ve read that if there has been a frost the night before the leaves fall, you can hear them tinkle as they land on each other below the tree.
Ginkgoes are surprisingly hardy. They are often planted in cities, where they don’t mind having their roots compacted under sidewalks, and where they shrug off air pollution as though it doesn’t exist. After all, they evolved during a tumultuous time for our planet, and they had to learn to thrive despite the sooty, sulphurous air of erupting volcanoes. Ginkgoes are also remarkably insect-resistant. In fact, there is almost no insect that even eat ginkgo leaves. Again, these trees evolved long before today’s leaf-eating insects were around. Ginkgoes are also resistant to temperature extremes and to wind.
So as I describe the wonders of this dinosaur-distributed, volcanic air-breathing, swimming sperm fertilized, living fossil (the gingko), I again kick myself for not purchasing that ginkgo tree five years ago. Yes, it was scrawny, but it would be five years older and five years bigger today. The tree is a wonder of nature, the only living bridge between the prehistoric plants of the ancient past and our modern plants of today. I do wish I had one of my own.
We end with a portion of a poem from Howard Nemerov, called The Consent. It was published in a book called The Western Approaches published in 1975.
One year ago this month, NC State Extension Master Gardeners in Durham County created a radio show. In developing their concept, the production team discovered that their show is the first in the country to be produced solely by Master Gardener volunteers. Michelle Wallace, Durham County Horticulture Agent, supervises the show but all of the recording, audio engineering, photography, website management, social media, and promotion is done entirely by her Master Gardeners. “We have an amazing group of volunteers in our county and they are always looking for new ways to teach people about gardening,” said Wallace.
Find Us on iTunes!
In January, the show expanded their format to include weekly podcasts of their episodes. “We are thrilled people can now find our stories on iTunes,” said Lise Jenkins, the show’s producer. Podcasting allows listeners to subscribe to the show and receive automatic updates that can be heard on a computer, tablet, or smartphone.
Podcasts Reach More People
While the show began in Durham County, surrounding counties are beginning to participate with agents and Master Gardeners being interviewed and serving as correspondents. Lucy Bradley, Associate Professor of Horticulture and Urban Horticulture Extension Specialist at NC State University, aspires to involve the whole state: “We have Master Gardeners all over North Carolina who are enthusiastic educators and want to help their communities. Using radio and podcasting is another way to reach out to the people of our state.”
Community Radio Stations
Initially carried on WCOM 103.5 FM in Carrboro, the show can now also be found on WDFC 101.7 FM in Greensboro. “We would like to continue to expand our reach by working with more community radio stations,” said producer, Lise Jenkins. “Our show being done entirely by volunteers is very much in synch with the mission of community radio stations,” she continued.
Where Horticulture and Innovation Meet
The show focuses on stories about the intersection of horticulture and innovation and the people who are leading the way. “One of the reasons I like working on the show is it gives me an opportunity to meet and interview people who are contributing to the public’s education and enjoyment of gardens and gardening,” said Harold Johnson, the show’s host.
The Mission of Extension
Carrying forward the mission of Extension means the show covers a lot of territory. Master Gardener correspondents have interviewed scientists, a New York Times best selling author, artists, homeowners, farmers, business owners, Extension agents, amateur and professional gardeners, and others. It also means the volunteers working on the show have had to learn how to master several different technologies. In addition to the regular radio broadcasts, the show has a website, a podcast feed which can be found on iTunes, a Twitter account, and most recently a Facebook page.
Six Month Project
“A year ago we decided to do a 6-month pilot project to see if a radio show could help us reach others in our community. We were surprised at the response,” said agent Michelle Wallace. She continued, “Every month our numbers keep growing. But what’s most exciting is the involvement of people from other counties. We are really starting to tap into the power of Extension and work together to help people all over our state.”
In recognition of this year’s National Seed Swap Day, January 31st, 2015, let’s consider the time-honored tradition of sharing seeds at such events because a Seed Swap has vast benefits for gardeners everywhere. Our nation’s third President, Thomas Jefferson, has long been known for his glorious gardens at Monticello with over three hundred varieties of more than ninety different plants. Jefferson sought plants and treasured seeds from all over the world and always shared his bounty and his seeds with his friends but thousands of those varieties of fruits, vegetables, herbs, and flowers have been lost in recent times to the growth, popularity and commercial availability of hybrid seeds.
Saving Seeds, an Ancient Tradition
Fortunately, long before organized seed exchanges were held, individuals across time and around the globe would harvest, save, and share their seeds. In some cultures, seeds were valued as if they were money, bartered with, traded, and collected. Seeds would be passed down from generation to generation, from one gardener to another. What gardener does not have at least one variety of produce or one favorite flower that he or she grows every year, having been grown by their own grandparent decades ago? Many historic varieties have been preserved in this fashion and are still grown today because someone, at some time, decided to save and share those seeds.
Our Founding Fathers Shared Seeds…
Today, the average home gardener can share their neighbor’s great uncle’s award-winning tomato seed and have the opportunity to purchase (or share!) the very same variety of beautiful black Hollyhock that Thomas Jefferson grew at Monticello. Today the home gardener can either choose to spend a small fortune amassing seeds or plants commercially purchased each year for that season’s garden, or with a little planning, patience and effort; can save the previous season’s seeds for planting the next year. The first seed swap days allowed local gardeners to trade their abundance of a particular seed for other kinds that other gardeners had in their own possession. Seed swaps have begun to sprout up all over the country and enable gardeners of all ages and experience-levels to meet, share seeds (and sometimes plants), advice and ideas, stories, and fellowship.
Why Save Seeds?
Today most organized seed swaps include seeds native to the area/zone, edibles (fruit and vegetable,) herbs, exotics, annuals, perennials and woody trees and shrubs. Seeds saved and shared are often open-pollinated and heirloom variety, which produce offspring identical to the parent plant (seed.) Seeds saved from a hybrid plant may show traits like its parents, but hybrid varieties do not always promise offspring like the parent as the hybrid is a genetic mingling of two different parent plants and may grow offspring differing in taste, color and growth habit. Bulbs and cuttings may also be shared. Gardeners are encouraged to bring their surplus, highly flavored and/or high-yielding/good-producing seeds to share and exchange with others.
In an age when “Going Green!” is all the rage, seed swaps are gaining popularity for good reason. Seed swapping continues to promote biodiversity, cultural history, and, in essence, recycling. Gardeners rid themselves of excess seeds without wasting and leave the event(s) able to try many new varieties inexpensively and resourcefully. Jefferson wrote that, “the greatest service which can be rendered any country is to add a useful plant to its culture,” and every year the National Seed Swap Day embodies both Jefferson’s legacy of seed sharing and his promotion of gardening throughout the Country. Thinking of hosting your own seed swap event? Find more information here: www.southernexposure.com/how-to-host-a-seed-swap-ezp-146.html
Submitted by Lois Versaw (Extension Master Gardener Intern at University of Nebraska-Lincoln)
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