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Emerald Ash Borer: Sad But True, Part 3

The invasive insect appears to have spread to a different host.

Tom Tiddens —  October 23, 2014 — Leave a comment

Last week, a college biology professor in Ohio announced he had found evidence that the emerald ash borer (EAB), an invasive insect decimating the continent’s ash trees, is also attacking white fringetrees (Chionanthus virginicus).

PHOTO: White fringetree in bloom.

White fringetree (Chionanthus virginicus) in bloom

In August he found the telltale D-shaped exit holes on a fringetree near his home. When he investigated further by peeling back the bark, he found feeding galleries and live borers. He had the borers positively identified morphologically as well as with DNA tests conducted by the USDA’s Animal and Plant Health Inspection Service (APHIS). He also found evidence of EAB activity on fringetrees in three other locations in Ohio.

The recent discovery marks the first time EAB has been found completing its life cycle on anything other than ash in the United States.

The finding adds an alarming new element to the EAB story:

  • Researchers have been wondering whether the host range for EAB could be wider than just ash. That theory had seemed unlikely up to now but is proven with the fringetree discovery. There has already been a lot of research investigating other possible hosts, and with the new discovery, there will likely to be more.
  • Is the insect adapting? This is a scary thought!
  • Will EAB kill fringetrees as it does ash, or just cause damage? So far the invasive insect appears to only be damaging—not killing—fringetrees.
  • Has EAB moved to fringetrees because EAB populations are locally so high? If the buffet is crowded at the “prime rib station,” it seems logical that “meatloaf station” may get some visits.
  • What will happen when ash tree populations dwindle? Will the EAB population die back, or just move to a secondary host (the meatloaf, as the prime rib is gone) and/or develop a completely new palate?
PHOTO: A D-shaped exit hole left by EAB.

This D-shaped exit hole was left by a mature emerald ash borer as it exited this host tree.

The Ohio professor’s find was not all by luck; he had reason to focus on the white fringetree. Laboratory studies have shown that the adult EAB will feed on the foliage of other tree species in the same family as ash—the olive family, or Oleaceae. Members include ash (Fraxinus), fringe tree (Chionanthus), lilac (Syringa), forsythia, privet (Ligustrum) and swamp privet (Forestiera). Literature from Asia, the homeland of the EAB, indicates other secondary EAB hosts.

The Chicago Botanic Garden has 42 fringetrees; all have been inspected and show no signs of EAB activity. Even a fringetree that is 25 feet from an ash tree that was heavily infested with EAB shows no signs. If you have a fringetree, you should inspect it for signs of EAB. These include dieback starting at the upper limbs of the tree, new growth on the lower trunk, and small, D-shaped holes where the larvae have exited through the bark. Emerald ash borer larvae can kill a mature ash tree in two to three years by destroying the tree’s vascular system.

Find more information on identifying and dealing with EAB on our website, and in our previous posts, Signs of Emerald Ash Borer, and Emerald Ash Borer: Sad But True, Part 2.

As the world has become less fragmented by ease of transportation, more exotic, high-consequence plant pests and pathogens like EAB have entered—and will continue to enter—the country. Other exotic plant pests and pathogens we are watching for at the Garden include the following: viburnum leaf beetle, Asian gypsy moth, brown marmorated stink bug, Asian longhorned beetle, thousand cankers disease, plum pox virus, chrysanthemum white rust, sudden oak death, and so on; most are already in the country. Vigilance and education are the key to managing and slowing the spread of these foreign invaders.

The Garden is a member of the Sentinel Plant Network, a group that unites botanic gardens in monitoring and providing education on exotic plant pests and pathogens, and works in partnership with the National Plant Diagnostic Network (NPDN).

If you are a plant and bug person like me, please consider becoming a NPDN First Detector and help be on the lookout for these exotic plant pests and pathogens. The NPDN offers an online training course to become a First Detector at firstdetector.org. It’s free, and upon completion, you even get a printable certificate!

©2014 Chicago Botanic Garden and my.chicagobotanic.org

Pumpkin Seed Math Games

Kathy J. —  October 20, 2014 — Leave a comment

If you carve a pumpkin for Halloween or make pumpkin pie from scratch, you’re going to have a lot of pumpkin seeds. You can put them to good use by turning them into “dice” and playing math games this fall.

First, you’ll need to remove, clean, and dry the seeds. After scooping the pulp from your pumpkin, place it in a bowl of water and gently rub the stringy pulp off the seeds. Rinse them in a colander and let them drain. Prepare a baking sheet with a layer of parchment paper. Do not add any oil. Spread seeds in a single layer on the paper. Bake in an oven preheated to 300 degrees Fahrenheit for 30-40 minutes to dry them. Store them in a plastic bag or airtight container.

PHOTO: Pumpkin seeds on baking tray.

These seeds were baked for just over 30 minutes at 300 degrees. After they have cooled, they will be ready to become instruments of learning.

The kind of dice you make will depend on the game you want to play, but for all games the basic idea is the same. Players will toss the seeds and the side that lands face up is the number they will work with. You’ll want to select seeds that are more flat than rounded. Remove any transparent skin that remains on the seeds, so it won’t dissolve in the marker ink and make a mess. Use a regular fine Sharpie or other permanent marker. I find that the extra fine markers tend to dry out while writing on the seed. You can use any color, but for some games the color matters. You’ll also want to establish a top and bottom of the seed. I write all the numbers with the point of the seed on the bottom so 6s and 9s don’t get confused. 

Here are some games you can make:

PHOTO: Pumpkin seeds painted like dominoes.

To make a game of “Count the Dots,” draw dots on one side of each seed as shown.

Count the Dots

This works well for young children learning to count. Take six pumpkin seeds. On one side of each seed draw dots like those on a die. Leave the other side blank. To play, toss the seeds and let them land. Count all the dots facing up. The person with the most dots wins!

Add the Numbers

Older children who are learning to add can play with numbers instead of dots. You can vary this depending on the skills of the children. For early learners, make two each of 1, 2, and 3. For children practicing higher number adding, make a range from 1 to 9. To practice adding higher numbers, make a set with all 6s, 7s, 8s, and 9s. Those are scary numbers to add until you get the hang of it, which is the whole point of this game.

To play, toss the seeds, then move the blanks out of the way. Line up the numbers so they are easier to see and add up.

Addition and Subtraction

Working on subtraction? Write the number on one side of the seed in black and write the same number on the opposite side in a different color such as red. Now when you toss the seeds, add all the black numbers and subtract the red numbers. The result could be a negative number!

PHOTO: Numbered pumpkin seeds.

Playing with addition-subtraction rules where black numbers are added and red numbers are subtracted, this toss would be 1 – 7 – 2 + 4 + 8 – 6 – 9 + 3 + 5 = -3.

Evens/odds

This game works with dots or numbers, but requires a set with writing on one side only. Players take turns predicting the outcome of the toss adding up to an odd or even number. The first player calls “odds” or “evens,” tosses, checks the results. S/he gets a point if s/he is right, a point goes to his or her opponent if s/he guessed wrong. 

Numbers and Symbols

You can have more than numbers on your dice. Make a set of seeds that include numbers and function symbols: + , -, ×, and ÷. Each player should have her own identical set of seed dice. All players toss at the same time and the person who can make the number sequence with the highest answer wins. In this game, players are allowed to combine numbers to make a larger number. For example, a 1 and a 2 can become 21, as long as all the exposed numbers and symbols are used. The simplest rules for this game will be to take the order of operations from left to right, but players who want to stick to the “PEMDAS” order of operations (parentheses, exponents, multiplication, division, addition, subtraction), can certainly work that into the game. 

PHOTO: Numbered pumpkin seeds and some with math symbols.

Working with numbers and symbols gives a score of 413 for this toss.

Matching Equations

To make the game more cooperative, play the same game above, only this time the two players try to make their two number statements equal each other, or get as close as possible. This is more difficult to accomplish. so it’s all right to be a little flexible with the rules, since the players are not competing and you won’t have to settle disputes.

Players can make up their own games. They can also work in more complicated operations like exponents, or they can arrange the placement seeds above and below a line to represent division (this may require paper and pencil). Chances are, if they have reached this level of sophistication with mathematical operations, they would prefer eating the seeds to playing with them, but it’s still a fun challenge.

Whatever their level, when players have exhausted their interest in the seeds, be sure to take a break and enjoy some pumpkin “pi.” Sorry, I had to include that, because let’s face it, if you’re playing math games for fun, you’re a person who appreciates this humor!

PHOTO: Pumpkin with carved numbers for facial features.

“Pascal Pumpkinhead” gave the seedy contents of its head for mathematics.


©2014 Chicago Botanic Garden and my.chicagobotanic.org

Are your summer or early fall container gardens looking tired? Change out your container gardens to extend your displays well into the fall.

PHOTO: Fall container garden with asters, mums, cabbages, and kale.

A fall container garden with asters, mums, cabbages, and kale. Photo by Tim Pollak

Gardening in containers can offer us year-round seasonal interest, and we can extend the garden seasons to create vibrant container gardens. I’m a huge fan of fall container gardens with a rich variety of color, texture, and hardiness that carry their beauty well beyond the first frost. 

A container garden that changes its appearance from one season to another is the definition of a seasonal “change-out” concept. Change-outs can be done by simply removing or adding one or more plants, objects, or other material to the container to add seasonal interest. Color alone can offer more impact on the container garden than any other design element. (However, nothing has more negative impact on the container garden than a poorly maintained appearance or bloomed-out flowers.)

PHOTO: Tall grasses at the back of this basin garden offset blooming fall annuals.

Tall grasses at the back of this basin garden offset blooming fall annuals. Photo by Tim Pollak

Change-outs should take advantage of seasonal blooming plants and colorful foliage and textures in prime condition. The change-out can add instant color or texture to the display and create a “wow” from one season to another. Color schemes can change through the seasons as well, such as pastels and soft tones in the spring, bright and colorful combinations in the summer, warm and autumn-like colors in the fall, to greens and interesting textures in the winter. Your container gardens can change and develop through the year much like a garden bed or border do in the landscape.

While chrysanthemums still reign supreme in many gardens and containers every fall, try other interesting plants such as asters, ornamental or flowering kale and cabbage, heuchera, pansies and violas, and ornamental grasses. These plants all are cold hardy, and will tolerate light frosts, lasting well through the autumn season.

PHOTO: A fall container with grass, pansies, and heuchera, which comes in a host of leaf colors.

A fall container with grass, pansies, and heuchera, which comes in a host of leaf colors. Photo by Tim Pollak

I love the combination of using purple or blue asters with ornamental kale—the colors play off each other nicely in a long-lasting display. Using other lesser-known plants—such as some of the fall-blooming salvias—can add height and create interesting combinations in your container gardens. Cold-hardy vegetables and herbs can also be added for interest and texture. I like using swiss chard, broccoli, Asian greens, parsley, and alliums to add interesting and colorful effects to my containers.

Another thing I like to do when creating fall displays in containers is to incorporate pumpkins, gourds, dried corn, branches and leaves of trees or shrubs, and autumn or Halloween decorations. A fun and simple addition to your fall containers may be to simply carve out a large pumpkin and use the pumpkin as a container, placing a combination of fall plants in it to decorate your front door or patio.

PHOTO: Fall container garden with cabbages, asters, and curry plant.

A fall container garden planted with cabbages, asters, and curry plant. Photo by Tim Pollak

©2014 Chicago Botanic Garden and my.chicagobotanic.org

Over 225 varieties of daffodils, tulips, crocus, and specialty bulbs tempt gardeners at the annual Fall Bulb Festival, presented by the Woman’s Board of the Chicago Horticultural Society.

ILLUSTRATION: Bulb planting infographic.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

It’s that time of year in schools again: time for science fair projects!
tomato project

As I’ve stated before, we in the education department of the Chicago Botanic Garden are committed to helping parents and teachers find great projects that teach students how plants sustain and enrich life. Last year we talked about using radish seeds; this year, it’s tomato seeds. And like last year, this project can be done by an individual student, a small group or ecology club, or an entire class.

Let’s begin by thinking about tomato seeds. Cut open a tomato and try to pick out a single seed. Go ahead and try it, I’ll wait.

PHOTO: This close up of a tomato seed shows the transparent coating that surrounds the tomato seed.

These tomato seeds glisten and mock me when I attempt to pick them up with my fingertips. The little brats also resist sliding off the cutting board.

 
As you will discover (if you didn’t already know) the seeds are coated in a gelatinous substance that makes them slippery and difficult to handle. So the first question is, what purpose does the slimy coating serve?

This is not the kind of blog post where I give you all the answers. That would not be good science teaching. I will tell you that tomato seeds can pass through the digestive tract of an animal and still germinate. Not all seeds can do that. It is possible that in nature, the coating protects the seeds on their journey from the mother plant through the hostile environment of a hungry animal’s gut and on to wherever that animal relieves itself.

Another theory is that the coating prevents premature germination of the seeds while they are inside the warm, moist, ripening fruit. Whatever the true reason—and there may be several—seed savers find it’s better to remove that coating after the seeds are harvested, because they become easier to handle and store.

The natural way to remove the coating is to ferment the seeds in a jar or bowl. It’s a simple procedure.

1. Scoop or squeeze the seedy pulp out of the tomatoes and put it into a bowl. (I prefer glass, but some people use plastic.) Add water equal to the volume of tomato pulp. Cover the bowl with plastic wrap and poke a few holes in the top.

PHOTO: glass bowl about a third full of tomato pulp, covered with plastic wrap, sitting on the windowsill.

Here are the seeds from three medium sized tomatoes, sitting by the window on the back porch, waiting to ferment.

2. Place the bowl in a warm location such as a sunny window. It is going to smell bad, so don’t put it in your dining room, unless you’re trying to reduce your appetite. You will also want to avoid fermenting your seeds next to bananas and other fruit ripening in your kitchen, because it can attract fruit flies. Leave it there for 3 to 5 days, depending on the conditions. Natural “beasties” in the air (yeast) will settle on the sugary goodness of the tomato. They will gorge themselves and reproduce, resulting in a yucky mess floating on top of the mixture. This is exactly what you want.

PHOTO: the bowl of tomato seeds is covered in white stuff.

In four days, my tomato seeds were ready, with a thin layer of white scum floating on top. Be very glad odors are not transmitted over the internet.

3. After you have grown a nice head of gunk on your seeds, remove that film and throw it away. (Unless you’d like to keep it for some reason.)  If you can’t skim all of it, no worries, the remaining goo will rinse off in the next step. Remove any floating seeds, too—they are not viable.

4. Pour the mixture into a sieve or wire strainer with fine mesh and rinse well, shaking the seeds gently to remove any remaining pulp and seed coatings.

PHOTO: The tomato seeds are spread out on a wax paper so they do not touch.

The most tedious part of the process is spreading out the seeds so they do not touch each other.

5. Dump the seeds onto wax paper. Poke at the seeds with a toothpick or other clean utensil to separate them. Remove any dark seeds that don’t look right. They are not viable. Let the seeds air dry on the wax paper in a protected place for about a week.

6. Store the completely dried seeds in an envelope until you are ready to use them.

PHOTO: close up of several tomato seeds - you can see the fuzzy outer layer of the seeds.

The cleaned and dried seeds are coated with tiny white hairs. These hairs were holding the gooey coating on the fresh seeds and now they will help the seeds soak up moisture when they are planted.

Now comes the science question: Do tomato seeds really need this kind of abuse to germinate?

The only way to find out is to experiment. Collect seeds from some ripe tomatoes—2 or 3 tomatoes will do. Ferment half of the batch using the directions above. Rinse the remaining half with water in a sieve (to remove any attached tomato pulp), and then dry them on wax paper without any other treatment. When you have all the seeds dried, use the same procedure from Eleven Experiments with Radish Seeds to measure and compare germination rates.

PHOTO: Ten tomato seeds are arranged on a paper towel in three rows; the towel is on a plate.

These ten fermented and dried tomato seeds are ready for germination testing.

Since you’re curious and kind of into this now, see if you can figure out if there are other ways to remove the seed coating that result in equal or better germination success. Some seed savers skip the fermentation and instead clean their tomato seeds with a solution of Oxi Clean. You can add this treatment to your experiment by dividing your batch of tomato seeds into three parts for: untreated, fermented, and Oxi Clean treatments.

The Oxi Clean method goes like this:

  1. Put the tomato seeds in a measuring cup and add water to make 1 cup of liquid.
  2. Add 1 tablespoon Oxi Clean power to the mixture and stir to dissolve.
  3. Let the seeds soak for 30 minutes.
  4. Rinse thoroughly in a sieve and dry on wax paper, just as you would with the other treatments.

As you will see, the Oxi Clean method is faster and there is no offensive odor, but is it better for germination?

PHOTO: A 16 ounce container of Oxi Clean Versatile Stain Remover

This product contains sodium percarbonate and sodium carbonate, no bleach, and will work for your experiment.

Note: if you Google information about this, you will find articles that discuss Oxiclean (one word) vs. Oxi Clean (two words). The two commercial products are made of different chemicals. The former is a liquid that contains sodium hypochlorite (chlorine bleach), the latter, promoted by Billy Mays, does not. For the purposes of this experiment, the less caustic, powdered Oxi Clean pictured in this blog post works perfectly well. Students should report the actual chemical names in the materials list, not just the product name. It’s just like using the scientific name of a plant instead of the common name—it’s more accurate and less confusing for someone who wants to replicate the experiment.

If you are ambitious, try a treatment of your own. After all, three tomatoes are going to give you a lot of seeds to test. My daughter tried soaking some of her seeds in vinegar. Perhaps regular dish soap or ordinary laundry detergent will remove the seed coating. Or you could try a cleaner that contains chlorine bleach. It’s up to you. Please remember to wear goggles and plastic or latex gloves while handling any chemicals because, like the tomato seeds, your eyes and hands may need a protective coating to escape harm.

I’d like to tell you what is going to happen, but then I would totally lose street cred and face ridicule from my science teacher peeps. One hint, though: be sure to measure the timing of germination as well as the number of seeds that germinate in each condition. If you want to know what happens, you’ll just have to cut open some tomatoes and try it yourself.


©2014 Chicago Botanic Garden and my.chicagobotanic.org