Posts Tagged ‘trees’

The Gingko Tree

Friday, April 29th, 2016

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

Ginkgo Biloba Leaves


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.
Golden Ginkgo Leaves


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.


Late in November, on a single night
Not even near to freezing, the ginkgo trees
That stand along the walk drop all their leaves
In one consent, and neither to rain nor to wind
But as though to time alone: the golden and green
Leaves litter the lawn today, that yesterday
Had spread aloft their fluttering fans of light.
This is Carol McPherson and this is Tree Talk.

Carol McPherson, NC State Extension Master Gardener Intern in Orange County, NC

Carol McPherson, NC State Extension Master Gardener Intern in Orange County, NC

Almost Wordless Wednesday: Excited about Phenology and Citizen Science

Wednesday, April 16th, 2014
Dogwood flower taken in Raleigh 4-12-2014 (photo credit Cheryl Perry)

Dogwood flower taken in Raleigh, NC 4-12-2014 (photo credit Cheryl Perry)

This coming week we celebrate both Earth Day (22nd) and Arbor Day (25th). When I think about focusing on the earth and trees, I think of phenology. The definition of phenology (literally the “science of appearance) is the study of how seasonal events, like migrations, are impacted by climate and other plant, insect and animal life, such as the first plants to bloom in the spring or when robins build their nests. Since the dogwoods are blooming where I live in North Carolina and since I recently signed up for the Cloned Dogwood phenology project, I thought what could be better than a look at dogwood flowers and the National Phenology Network’s flowering dogwoods project. Visit their site and learn more about this project and others!

Dogwood flower (photo credit Cheryl Perry

Dogwood flower North Carolina (photo credit Cheryl Perry)

Connie Schultz, Master Gardener/Composter (’95 Cornell Extension) now volunteering in Johnston County, NC

eLearn Urban Forestry Course for Extension Master Gardeners Available Through eXtension

Monday, April 29th, 2013


eLearn Urban Forestry is a new online course now available for Extension Master Gardeners and others interested in learning more about urban forestry.

As most of us know, healthy urban forests require a strong investment, and not just from the individuals and communities who benefit directly from these forests, but also from volunteers and professionals providing the expertise and care to support them. As an Extension Master Gardener volunteer, you might find yourself interested in knowing more about what it takes to select, plant, and maintain trees in urban areas to ensure their maximum benefit.

Well, now you can with eLearn Urban Forestry, a state-of-the-art online learning opportunity designed specifically for those working or volunteering in urban forestry situations, but not classically trained in urban forestry. eLearn Urban Forestry in part of the new Trees for Energy Conservation resource area on eXtension, and is led by urban forestry team members from across the U.S

Complete eLearn Urban Forestry Course to Earn Credits/Certificate

The eLearn Urban Forestry Course is available for volunteer credit/certification, but individual modules can also be viewed at anytime, in any order, as a training resource.

Check with your local Master Gardener coordinator to see if you can earn volunteer credit and/or apply your certificate of completion to your local program training requirements. (Note: If you found this blog posts and are looking for professional credits to apply to your work, you can access the site for credit from the International Society of Arboriculture and Society of American Foresters, by visiting You can also review modules for free by visiting

Access the training for Extension Master Gardeners by visiting (see how to enroll below).  This eLearn Urban Forestry course is made up of 10 modules, each module being about 1 hour each. The modules are interactive and self-paced and the whole program can take around 10-15 hours to complete.

Module topics include:
  • Module 1: Costs and Benefits of the Urban Forest
  • Module 2: Tree Growth and Development
  • Module 3: Urban Soils
  • Module 4: Site, Tree Selection, and Planting
  • Module 5: Arboriculture
  • Module 6: Assessing and Managing Tree Risk
  • Module 7: Tree Disorder, Diagnosis, and Management
  • Module 8: Trees and Construction
  • Module 9: Public Policy and Urban Forestry
  • Module 10: Urban Forest Management
eLearn Urban Forestry EMG

eLearn Urban Forestry for Extension Master Gardener through eXtension

How To Enroll in eLearn Urban Forestry for Extension Master Gardeners

1)Visit the eXtension website,

2) Set up an eXtension Campus (Moodle) account:

  • “Create an account” link (top, left side of the page) via the secure connection.
  • Once you have that account created, you will receive an e-mail with a confirmation and a password. Follow the instructions in the email to complete your account set-up.
  • Remember your login and password so you can access this or other future courses.
Create an eXtension Campus Account

Create an eXtension Campus Account (click to enlarge image)

3)Login to the course

  • After you create an account, log into eXtension Campus (Moodle) ( ) . Find the log in entry at the top, left side of page, where you first created the account.
  • Scroll through the available course categories and select Master Gardener (under Yard and Garden).
Find eLearn Urban Forestry for Extension Master Gardeners under 'Yard and Garden'

Find eLearn Urban Forestry for Extension Master Gardeners under ‘Yard and Garden’ (click to enlarge image)

4) View the course and get started

For more information, see:

Rake and Take Master Gardener Project: Coordinating Fallen Leaves into Gardener’s Gold

Monday, April 22nd, 2013

{Editors note: The Howard County Maryland Master Gardeners  Rake and Take volunteer program that helps turn one’s surplus of leaves into another one’s mulch and compost was worth waiting to share for National Volunteer Week, Earth Day and Arbor Day celebrations – as it hits on all these themes. Thank you Pat Hooker and the HCMDMGs for sharing the story about how this program is coordinated and implemented. – Karen Jeannette}

What is Rake and Take?

“Rake and Take” is a program of the University of Maryland Extension Howard County Master Gardeners which pairs leaf ‘Rakers’ with leaf ‘Takers’.

Rake and Flyer

Clip from ‘Rake and Take’ flyer

Rakers agree to bag pesticide/herbicide-free leaves and place them at the curb of their residences. Takers agree to pick up the bags. Takers either use the leaves for their own compost piles or shred the leaves for mulch.  Some leaves even make it to the compost demonstration sites in Howard County (see our composting page for more info) via members of the HC/MD/MG Composting Committee.

While most of the Takers have been Master Gardeners, the Rake and Take program is open to any Howard County citizen and several non-Master Gardeners participate, especially those who have recently become interested in composting.

Information about the composting demonstration sites is included in the promotional Rake and Take flyer.

What does Rake and Take Look Like?

First the ‘Rakers’ rake and bag

Raking leaves

Raking Leaves

Bags of leaves waiting to be shredded

Bags of leaves waiting to be shredded

Then the “Takers’ shred leaves


Shredding leaves under tree

Then “Takers’ mulch….

Some leaves mulch garden beds

Some leaves mulch garden beds

..or make compost

Some leaves go to compost heap

Some leaves go to compost heap

Insulating compost pile in late fall with leaf bags

(The compost pile gets insulated in late fall with leaf bags)

The compost is cooking

The compost ‘cooking’

Compost - 'black gold' on a garden bed

Compost – ‘black gold’ on a garden bed

Rakers and Takers Get an Opportunity to Talk ‘Compost’

Sometimes Master Gardener Takers have an opportunity to have a conversation with Rakers and this year we are asking them to share a Backyard Composting brochure to educate more people about composting. When Takers have a chance to interact with Rakers it is a very positive experience for both and helps spread the word about good gardening practices.

How Rake and Take is Coordinated

As the Rake and Take coordinator, I keep a database of names, addresses with zip codes, e-mail addresses and phone numbers of participants. Both Rakers and Takers register with me annually. When a Raker notifies me they have leaves available I use the zip code to match with a Taker in the same general neighborhood (for the sake of mutual convenience) if I already have a Taker name.

Otherwise I send a notice to the Howard County Master Gardeners e-mail list stating the number of bags and the general location of the leaf pickup. When I get a response, I provide the contact information to the Taker, who then makes pickup arrangements with the Raker. I make a point of not including personal contact information on the e-mail list posting since that is freely available to the general public on the web. In some cases people who have been paired one year contact one another directly the following year and the relationship continues from one year to the next.

Promoting Rake and Take

The program is advertised through local newspapers, on our Howard County MG Rake and Take website and on the Howard County Green Central Station website. Lindsay DeMarzo who writes a blog for Green Central station in Howard County MD has recently done a very nice posting “Share the Wealth with Rake and Take’ about our Rake and Take program. Additionally we distribute the Rake and Take flyer at the Plant Clinics during the late summer and fall months.

If you are interested in coordinating a Rake and Take project near you, we’d be happy to answer any question you may by contacting us through our  Howard County MG Rake and Take website.

by Pat (Patricia) Hooker
Howard County MD Master Gardener

Viewer Discretion Advised

Monday, March 7th, 2011

Photo by Holly Scoggins (Virginia Tech)

Occasionally, but not often enough, I check in at the Garden Professors blog. They’ve recently posted some horrifying, intriguing, and must see photos of what people do to trees. To the right is an example, which is part of a post titled “Unspeakable Acts of Pruning:”


The blog makes it convienient to see all tree oriented posts through their “What About the Trees” link. Most of the posts are “best practice” and “how to” oriented, but their “horror show” posts are a fun change of pace.

The Garden Professors are Jeff Gillman (University of Minnesota), Linda Chalker-Scott (Washington State), Holly Scoggins (Virginia Tech), and Bert Cregg (Michigan State). They provide interesting, informative, and always science-based tips and observations that can help any homeowner. The four of them post several times per week, so there always seems to be something new.

My favorite picture is below…pretty soon this sign might say “swimming allowed.”


Bill HoffmanUSDA/NIFA

Photo by Linda Chalker-Scott (Washington State)

Emerald Ash Borer University: Providing Webinars and Information on Invasive Forest Pests

Monday, February 28th, 2011

Guest post provided by Robin Usborne, Michigan State University; Amy Stone, The Ohio State University Extension; and Jodie Ellis, Purdue University

What’s “Bugging” You?

EAB University logo

EAB University, offering free webinars, and information on invasive forest pests

Sometimes they hide in wood packing material from shipping ports all over the world. Other times they hitch a ride in a load of firewood going to a campground or summer cottage. But once they’re here, the trees are never safe.

Sounds a bit like a horror movie, but invasive forest pests like the emerald ash borer (EAB) can wreak havoc on North American woodlands and urban forests. As the pest invasion continues across the U.S. and Canada, communication and outreach is vital to combat the onslaught, but in these days of slashed travel budgets and increased conference expenses, it takes some creative thinking to get this information to those who want it.

EAB University – Free Webinars and Invasive Forest Pest Information

That’s where Emerald Ash Borer University comes in. EAB University is a series of free webinars that bring information on the latest issues surrounding EAB and other invasive forest pests to anyone needing the information. The webinars are given by scientists and experts in the field, and anyone with a computer with Internet access can view them. EAB University was developed by Michigan State University, Purdue University and the Ohio State University communications specialists who have been dealing with the invasive pest since it was discovered in North America in 2002, and is funded by the USDA Forest Service, Forest Health and Economics Division. Webinars are much like a presentation given at a conference, but the conference room encompasses the world. Participants are able to comment and ask questions via a “chat” function during the webinar, and the presenters provide contact information for anyone needing additional information.

EAB University was launched in 2010, and quickly became a hit. More than 1,200 people registered for the sessions, and those who weren’t able to “attend” the live webinars were able to watch the recorded sessions, which are archived on the website.

New this year –  expanded curriculum covers more invasive forest pests

This year, EAB University has expanded the curriculum to include webinars on other wood-boring pests and diseases, such as hemlock wooly adelgid, thousand cankers, Asian longhorned beetle and viburnum leaf beetle.

Extension educators, arborists and tree care specialists have offered EAB University webinars as part of their education and outreach meeting schedules. Continuing education credits are available for many of the live webinars. These sessions are the next best thing to having the experts in person.

Visit Emerald Ash Borer University on the website. You can watch an archived webinar, or mark your calendar for an upcoming session of interest. These webinars bring experts from around the country right to your computer, anytime and anywhere. Thanks for your
interest in keeping those bad bugs at bay!