Archived Chat with Jeff Gilman

Moderator: Great questions everyone, but I am afraid we have run out of time. I would like to thank Jeff Gillman for taking the time out to answer all of our questions. Make sure you look for him in video if you have not already. Our next chat session will take place with Natural Resource Specialist, John Moriarty tomorrow at 9:00 a.m. We hope to see you all then!
Jeff Gillman: Most of the trees that you saw in the video were different species though a few were the same species and just grown a little bit differently before they were planted. Thanks for all of the questions. It has been fun and I look forward to more next time.
Moderator: The last question this morning comes from Dave in Madison: 'Are those elm trees in the video all different species?'
Jeff Gillman: Trees are picked for a number of reasons. The most important include whether the tree is "neat" (in other words does it drop alot of seeds and leaves), trees in the city should be able to tolerate pollution. Trees in the city must also be able to tolerate living near a lot of concrete. Finally, the tree must look good. Noone wants an ugly tree in their yard.
Moderator: Noah in Minneapolis wants to know: 'Why do people pick certain trees to plant in the city?'
Jeff Gillman: Very good question. Most diseases that attack animals don't attack plants and most diseases that affect plants don't attack animals. For example, roses don't get athletes foot, and you don't get black spot.
Moderator: Follow up question from Jane: 'Why don't the Dutch Elm beetles get sick with Dutch Elm Disease?'
Jeff Gillman: Wow, now that's a tough question. I like all plants a little. Probably my favorite plant is one that I mentioned earlier, the Butterfly bush. I like it because it has large beautiful flowers that attract butterflies (especially swallowtails)
Moderator: Kim from St. Paul was curious: 'what is your favorite kind of plant?'
Jeff Gillman: The best way is to buy a good field guide such as a Petersons guide. But, in general, Elm trees have teardrop shaped leaves whose edges are rough. Elms are also generally very tall tree.
Moderator: One more question from Sally: 'How can I identify an elm tree?'
Jeff Gillman: I'm not sure about that one -- I think that the astronauts take their food with them -- but they do use hydroponics for experiments up there. Here's an interesting note -- Hydroponics was first used in a large scale to provide fresh vegetables for soldiers fighting in the second world war.
Moderator: Shane from Lake City was wondering: 'I heard that they use hydroponics to grow plants in space. Is this how the astronauts get their vegetables?'
Jeff Gillman: Good question. They sure do. Two pollutants -- Ozone and Sulfer dioxide are particularly harmful to plants that live in the city. Some plants have the ability to live with high levels of these chemicals, but some plants suffer quite a bit. Butterflybush is a flower that is particularly sesitive to urban pollution.
Moderator: Linda from Chicago wants to know: 'Do plants that grow in the city have problems with pollution?'
Jeff Gillman: Yes -- Well, perhaps I shouldn't be so quick to say yes. Dutch Elm disease may have started somewhere else, but I think that it was first identified in Holland.
Moderator: Another great question from Sally in Minneapolis: 'My cousins have a Mother from Holland and they speak Ductch at home did Dutch Elm Disease come from Holland?'
Jeff Gillman: That is a great question. The answer is that we don't. Part of what we are testing is the ability of different types of Elm trees to resist the disease, so we actually want the disease to be present. After all, if the disease isn't present then we'll never know if a tree didn't get the disease because it was resistant or if it didn't get the disease because the disease wasn't around in the first place.
Moderator: Amy from Lakeville has a great question about the elm tree project: 'How do you know that the other elm trees in your project won't get a disease?'
Jeff Gillman: If salts (and again we're not talking about table salt here -- the fertilizers that you use on your houseplants are salts and are the kinds of salts that I'm talking about) are not getting to the plant then the plant will die. It may take some time for the plant to die though. Just like you and I can go for a little while between meals, so can plants. If we take all of the necessary salts away from a plant it should take them at least a week or two to die.
Moderator: Jenny from Madison was wondering: 'What happens to plants if they don't get any salt?'
Jeff Gillman: Wow, now that's a complicated question. There are many, many chemicals that a plant could use. But here are a few examples. Capcacin is the chemical that makes hot peppers hot -- it also poisons insects. The white sap in a milkweed plant is a poison, it affects insects hearts. So there are many different poisons. Perhaps the best example is one that affects you and me too -- Poison Ivy.
Moderator: Sandy from St. Paul wants to know: 'What kind of poison do plants have inside their leaves to keep bugs from eating them?'
Jeff Gillman: Very good question. The chemicals that we put into the hydroponics solution are salts -- very similar, but not quite the same as, the salt that you put on your food. Salts contain different elements such as nitrogen, phosphorus and potassium that provide nutrition to the plant. In the soil the same salts are required as in the hydroponic solution, but in the soil these nutrients will stick to pieces of the soil. Hydroponics does allow the plants to get the chemicals more easily and so plants usually grow faster in hydroponics.
Moderator: William from Minneapolis wants to know: 'What kind of chemicals do you put in the hydroponics bucket and how do plants that grow outside get the chemicals they need?'
Jeff Gillman: We have to measure the trees so that we know how fast they are growing. People often ask us what the fastest growing tree that we have is. Without taking measurements we would be guessing -- in research you can't do much guessing.
Moderator: Shea from Minneapolis was wondering: 'Why do you have to measure all those trees in your research?'
Jeff Gillman: If the plants roots are in some kind of a liquid solution instead of soil then yes, it's hydroponics. You can grow plants in hydroponics as long as you have enough nutrients there for the plant to use. As long as you are adding new nutrients and water you can grow plants in hydroponics for years and years.
Moderator: Phillip from Anoka wants to know: 'How long can you grow plans in hydroponics? I grew an avocado in water once. Was that hydroponics?'
Jeff Gillman: Great, great question. Yes, what the lady beetles do is a type of hibernation. The lady beetles don't freeze because the have a type of natural antifreeze in their blood.
Moderator: Trudy from Minneapolis wants to know: 'Do lady bugs hibernate in the winter? How come they don't freeze to death?'
Jeff Gillman: Well, there are many ways. The best way is to pick a rose that doesn't usually get black spot though. The best type of rose to pick is a Rugosa Rose. These roses are resistant to balck spot. If you want to protect roses that you already have then there are many over the counter pesticides that can help to slow down the fungus. One final recommendation, be careful not to water the leaves of your roses when you water. Watering the leaves will help the fungus to grow and hurt the rose.
Moderator: Nancy, also from Minneapolis, is concerned: 'My mom grows roses, how can she prevent them from getting black spot?'
Jeff Gillman: Black Spot is, like Dutch Elm Disease, a fungus. Spores (fungus seeds) are spread by the wind. Spores can travel a great distance to get from one plant to another.
Moderator: Jack from Minneapolis wants to know how roses get blackspot.
Jeff Gillman: There is not much hope for a tree that gets Dutch Elm Disease. We (University folks) generally recomment that you cut the tree down and burn it so that it can't spread the disease to other elms in the area.
Moderator: Jane from Minneapolis has a follow up question: 'If an elm tree gets Dutch elm Disease, does it die for sure?'
Jeff Gillman: When I was at Georgia I studied many different bugs including the two-spotted spider mite, a major pest of many different plants, and the fall web-worm which many of you may be familiar with. It's one of the caterpillars that makes tents in trees during the summer months.
Moderator: Mark from St. Paul is curious: 'What kind of bugs did you study when you were going to school in Georgia?'
Jeff Gillman: You will know that an Elm tree is sick by yellowing leaves and by the tree dropping its leaves in the summer instead of the fall.
Moderator: Great! Our next question is also about elm trees. Kim from St. Paul wants to know 'How can you tell if an elm tree is sick?'
Jeff Gillman: Dutch Elm Disease is a fungus. It is spread by elm leaf beetles and by roots that contact each other under the surface of the soil.
Jeff Gillman: Dutch Elm Disease is a fungus. It is spread by elm leaf beetles and by roots that contact each other under the surface of the soil.
Moderator: Our first question this morning comes from Jane in Minneapolis. She wants to know: 'what causes Dutch elm Disease?'
Moderator: Greetings Jeff, and hello to all of the Bell LIVE! participants joining us this morning. I see we already have some great questions coming in! We will start the chat at 10:00 o'clock sharp.
Jeff Gillman: Hello, Jeff Gillman here. Looking forward to beginning the discussion.