The Garden Professors™ – Page 137 – Advancing the science of gardening and other stuff since 2009

EverGreen or EverYellow?

In last week’s post I mentioned that many tree problems can be difficult to diagnose and require a thorough inspection and site analysis to get to the root of the problem. In contrast, a recent issue that has generated a lot of calls is easy to explain and is not a cause for major concern. Many homeowners and others are alarmed that needles on their white pines are turning bright yellow.

“Is my pine dying?”

The key in assessing this situation is looking at which needles are turning color. Except for southern pines, most conifers produce only one, single flush of new needles each spring. Because of this, we can work our way down a shoot and tell when each group of needles was formed. The outermost needles were formed in the current year, needles in the next internode were formed the year before, needles formed in the next internode were formed the year before that, and so on. Most evergreen conifers keep their needles for 3-6 years and then the needles senesce and fall off. The longest-lived needles, perhaps not surprisingly belong to bristlecone pines, which are also the longest living trees on earth. Bristlecone pines, the oldest of which is over 4,500 years old, have needles that persist for 13 to 17 years. But I digress, back to the white pine. White pine needles last 2 or 3 years. Each fall, many of the previous year’s needles turn yellow and senesce. Since the needles often turn bright yellow and almost half the needles on the tree are affected it can certainly grab attention. As long as only older needles are turning, the process is natural and there’s no need for concern. On the other hand, if this year’s needles are dropping that’s another issue and warrant further investigation.

White pines don’t keep their needles very long. As long as this year’s needles aren’t senescing, the tree should be OK.

Pining to learn more about conifers? The Gymnosperm database http://www.conifers.org/ is an awesome and authoritative site that has information on just about every conifer known to science.

Blog bizarre

Jeff’s post yesterday gave me the perfect opportunity to showcase the star of my bizarre book collection.. It’s called “Evolution of Botany: More Fact Than Theory” written and published by Benjamin Zarr (author of several other books, including “Evolution: No One Can Break Down My Theory!”) Jeff, he’s written more books than you and I put together.

This book was “willed” to me by a dear colleague at Buffalo State College after he retired. When I first received it, I tried to read a chapter, but found it impossible to finish. Here’s an example of one of the numerous illustrations on a chapter about plant heredity:

The discussion around this illustration is too long for this blog. Plus, it hurts my brain. You might notice some interesting botanical terms, like “red paste” and “yellow dough” for instance. Here’s part of the text on these details: “I say red “dough” and red pastes always reproduce the color red because pollen always inherit a specific “melting” point. When the heat of the sun warms the starchy contents of a seed or the pastes of a seed coat red has the lowest melting point therefore it shows up before any other color. Just like in a specturm of light red appears first and purple last, all other colors come in between. When red has been eliminated it fades into pink, then into the color with the next higher melting point until white appears as the hardiest color of all.”

Ack.

Not content to write just about plants (which evolved after animals, but that’s a whole different chapter), he ventures into the evolution of animals:

Words fail me. (But they don’t fail a reviewer for the Quarterly Review of Biology, which you can read here.)

Though this book is an extreme example, it fits in with Jeff’s post yesterday about critical thinking. (If you’re interested in the dissection of yet another book – The Sound of Music and Plants – click here for an online column of mine from 2003.)

RAWRRR!

Posted in honor of Garden Rant’s Halloween-related garden photo contest.

Pick me, Amy, pick me!!!

Now For The Scary Part

This little dude is the Florida Semaphore Cactus, native only to hardwood hammocks in the middle and lower Keys. According to the Center for Plant Conservation, “Opuntia corallicola may very well be the most endangered plant in the United States.” Only one wild population remains (eight individuals), plus a few sites of re-introduction. Loss of habit and an exotic cactus moth have contributed to the demise of this most personable of cacti.

Arbitrary travel tip: I snapped this photo during a recent visit to the fabulous Key West Tropical Forest & Botanical Garden. Please pay them a visit if you’re ever in the vicinity – they are doing so many great things, with so little $$$, as is the case for many small public gardens. And then head straight to Kelly’s on Whitehead Street for outstanding $3 margaritas…served in a pint glass!

As Bad As It Gets?

Last week I took a look at old, out of print books that are worth finding and reading. This week I think I’ll take a slightly different track and instead turn my attention to a book that is currently in print, but which shouldn’t be. In fact, 1001 All-Natural Secrets to a Pest-Free Property by Myles H. Bader can be found in many bookstores, was actually one of the best selling garden books of 2006, and is still selling today. There are other books that I have problems with (Jerry Baker comes to mind) but when considering the worst of the worst this book is all by itself.

I was first introduced to Dr. Bader (he reportedly has a doctorate in Preventive Care from Loma Linda University) one night when I couldn’t sleep. He was on one of those “paid programming” shows talking about homemade cures for insects around the house. Normally these half-hour long advertisements cure my insomnia, but not this time. As someone who loves to learn about and test homemade remedies I was mesmerized by his recommendations and quickly ordered the book. Sure, on the show he seemed to “dumb things down” a little, but here was a bonafied professor who might have some really cool stuff for me to look at! I couldn’t wait.

After I received the book I discovered that Dr. Bader used the English language poorly. This didn’t turn me off to the book though. I’m pretty forgiving of bad English. I know that mine isn’t the best and there are sections in all of my books which still haunt me. Still, the sheer number of errors in Bader’s book was staggering. For example, here’s a paragraph from page 3: “His interests have always been in the field of food and cooking and many of his books are related to helping the chef or cook with cooking and kitchen secrets that may gave been forgotten over the years. This has lead him to include household hints and other related subjects in his books.” (yes, the words gave and lead are used in the book exactly as they appear above). And this is just the first page with a significant amount of writing!

Still, I didn’t buy this book for good editing; I bought it for cool, “all-natural” cures. And so I turned the pages hoping to find something useful. On page 23 I discovered that the insecticide “Sevin” is organic and is composed of pyrethrums and diatomaceous earth (This is completely wrong, the active ingredient in Sevin is carbaryl, a synthetic insecticide). I also learned, on the same page, that mixing horse manure with hot water, letting the mixture cool, and then spraying it onto fire ants will kill them (What!?!!?). There are no instructions about how much of the manure or hot water to use. Other interesting remedies that you should probably avoid include spraying hairspray onto flies to kill them and using a mixture of 1/3 cow manure, 1/3 sand, and 1/3 clay to coat the trunk and branches of a tree infested by aphids (I’m not sure how this would work since most aphids attack the leaves of trees…). At the end of the book there is a glossary where I learned that Rotenone is a low toxicity poison (never mind that this organic poison was recently voluntarily withdrawn by its makers for use as an insecticide at least in part because of safety/health concerns). Indeed, almost every organic pesticide was treated lightly, apparently simply because they’re “natural” (which, as some of you may know, is a pet peeve of mine).

The interesting thing about this book is that there were a few useful tips, but with so much hooey it was often tough to tease those tips out. If you’re one of those people who thinks that a book can be so bad that it’s good then you might enjoy paging through this book, but, other than that, I think this book is best used as a doorstop.

And now I have a challenge for all of you. Does anyone know of a worse book? (and, if so, where can I buy a copy?)

Size matters.

Yesterday I received a call from an administrator at a large military base. (I have to tell you that anytime I get a call from someone in government I immediately start wondering about “the file” that I’m sure is kept on me. No, I’m not paranoid, but I’m an outside reviewer for a number of graduate student theses from the University of Agriculture in Faisalabad, Pakistan. In fact, I’m doing two right now. So every once in a while I am sent a brown paper package from Pakistan. They’ve always been opened and resealed by the time I get them. But I digress.) Anyway, the administrator from the LMB was concerned about a newly installed landscape on the base. Requirements for landscapes around military buildings specify that plants must be placed a certain distance from the building itself, and not be tall enough to hide people or large objects. So my caller was concerned that the winter creeper (Euonymous fortunei) which had been planted would start to do exactly what its name implies. Furthermore, he had done a little Googling and found reports that this plant can get quite a bit taller than what the LMB specifications require. However, the landscaper was adamant that this plant would not exceed the height requirements and cited one of Dr. Michael Dirr’s books as evidence. So what, the caller asked, did I think about this?

Several years ago I wrote a myth column on plant size, which you can read here. Part of this column immediately sprung to mind: “The lack of consensus among tree identification guides, taxonomic literature, nursery tags, and real-life landscape specimens underscores the fallacy of assuming a uniform maximum height for any species, variety, or cultivar of any tree or shrub.” In fact, the best predictor for mature plant size – especially for nonnative species – is performance in your local geographic region. With this in mind, I called my colleague Dr. Sarah Reichard (an excellent plant taxonomist) at the University of Washington. She laughed when I explained the situation and said that a local specimen at the Washington Park Arboretum had become such a nuisance that the grounds crew had to whack it into submission. Not only was it well over 12” tall, but it had crept into the nearby Magnolia and was busy making itself at home.

Don’t have a photo of the Magnolia-eating creeper, but I do have this nice truck-eating ivy.

What about the Dirr book? It’s an excellent resource, but it doesn’t necessarily take into account how climatic differences can influence plant height. In contrast, the Western Garden Book (by Sunset magazine), though not an academic resource, does look at local plant performance in its descriptions. I was also annoyed to find that this introduced species is invading the eastern US and is considered a weed in some states. There are lots of good plant choices out there. Let’s not aid and abet the invasives.

So my caller was armed with definitive evidence and the landscaper will probably have to absorb the replacement costs. The lesson: don’t rely on books alone. Do some legwork in your area to find out what plants are up to – literally.

Sidewalk-eating Japanese maple – not an invasive, but easily outgrows its “expected” space

The Heartbreak of Plagiotropism…

…Otherwise known as “splayage”. When vegetatively propagating some species of woody plants, care should be taken when selecting where to take a cutting (piece of stem) to root. Propagation from terminal cuttings (pointy end up) usually results in orthotropism or a vertical growth habit. Cuttings from extremely lateral branches (those that grow parallel to the ground) can, in a few species, result in a spreading growth habit or plagiotropism.

This is not always undesirable – some species are purposefully propagated this way to maintain the prostrate habit that particular cultivar is known for. I’ve propagated lots of Buddleia over the years and don’t recall having this happen. Jeff, you were “Mr. Buddleia”* back in our days at UGA…please weigh in on this!

Floppulence
Buddleia davidii ‘Santana’, author’s garden.

Said plant was purchased from a little Mom & Pop greenhouse as a 4.5” pot with a 6” tall rooted cutting, and it went into our garden in May. It is now lolling all over its neighbors like a drunken sailor. What looks like a vertical piece in the back is simply propped up by the Canna. No big deal, just a good teaching moment.

‘Santana’ is a bit slower-growing than most cultivars of Buddleia, yet is in great demand due to the wacky variegated foliage. My guess? This is the result of repeated acts of propagation via lateral branches…cuttings of cuttings of cuttings. Not to mention the fact that it’s patented, so this guy may not only be floppy, but illegal (!). One of the purported upsides of the plant patenting process is to control the quantity and quality of propagation through licensing. But that’s another post topic for the future.

*Not to be mistaken for the pageant winner “Miss Buddleia”

Support your local arborist

A couple of weeks ago I was interviewed for the local paper about this year’s fall color. It’s pretty standard fare around these parts; newspapers, AAA, and so on want to know if we’re going to have good fall color, will it be early, will it last long. I mentioned to the reporter that we’re seeing a lot of early fall color in the maples around mid-Michigan, in contrast to the northern part of the state, which appears to be running a little late. The question of course, is why. I noted even though this summer was relatively cool, trees have been stressed the past several years and some pests, such as clearwing borers, that might not normally be major problems may be taking advantage of the situation. After the article appeared in the Lansing paper, it was picked up by the Chicago Tribune and USA Today (must’ve been a slow news day). Since then my volume of “What’s wrong with my tree?”calls and e-mails has skyrocketed. Depending on how busy I am I usually make an effort try to respond to homeowner calls. A few issues, such as tar spot on maple, can be diagnosed sight unseen; “My maple has little black blotches on the leaves that look like tar spots”. Most serious tree problems, however, require a site inspection in order to fully evaluate and diagnose the problem.

If callers and e-mailers really want to get to the bottom of their tree problems I usually tell them to contact a professional, certified arborist in their area. The International Society of Arboriculture (ISA) provides training and certification for professional arborists. In order to be certified, arborists must meet certification standards and take continuing training to maintain their certification. Being an arborist is a tough job. And the business of being an arborist is made tougher by the low barriers to entry. Anyone can buy a chainsaw, slap a magnetic sign on the side a pickup, and advertise himself or herself as a tree service. Quality, professional arborists have to pay for training, insurance, bonding, up to date equipment, and proper safety gear for all employees. It’s not a very level playing field. But for the client that is looking to save the oak tree that Grandpa planted when he moved into the house after the war, the knowledge and expertise of a professional is far preferable to the chainsaw of Joe’s Fly-by-night tree service.

To find a professional arborist in your area look in the Yellow pages under Tree Services and look for arborists that are ISA certified and insured. Also the ISA has a search feature on it’s website that enables homeowners to find an arborist based on their zip code.

Old Books

It’s a rainy day in the upper Midwest. My favorite time to read. Of course, I should be writing papers, grading papers, or setting up seminars for next semester. But instead I’m drawn to my bookshelves. In most professors offices that I visit the shelves are an odd mix of old and new books that focus on the particular subject which that professor works on, along with the scientific journals that relate to that discipline. It’s no different in my office, except that I tend towards older books and my tastes are just a little bit more eclectic than most. I have a particular fondness for old entomology texts and I also like books on garden remedies — whether old or new, academic or not.

In a future post, maybe next week or so, I’m going to go down a rogues gallery of books that I don’t care for, old or new. But today I’m going to do something a little different, I’m going to tell you the three books that I think are must reads for any gardener or horticulturist. But the catch is that none of these books are currently in print and so you’ll need to search for them or go to Amazon.com where you can often find dealers who have used copies. These books aren’t listed in any particular order, except the order in which they came to my mind when I put this post together.

Best Reading Book — The World was my Garden, written by David Fairchild, is one of the best horticultural reads of all time. I’ve heard Fairchild called the last of the great plant explorers as well as the father of modern plant exploration. Either title works. I wouldn’t call him the greatest plant explorer of all time (though it’s no stretch to say that he was one of the best), but he is certainly the most skilled writer (at least in my mind).

Best Informational Book(s) — The Standard Cyclopedia of Horticulture edited by L. H. Bailey is a series of three (or more depending on the edition you get) books which is basically a humongous encyclopedia of everything horticultural. The beauty of these books is the amount of information they deliver along with the appreciation that the writers (and especially the editor who many consider the father of modern horticulture) had for the art and science of horticulture. So often we, as professors, want to explain things “scientifically.” Sometimes gardeners just want to talk about horticulture as an “art”. This cyclopedia does a great job of appreciating horticulture from both sides. My favorite section is one called “horticulturists” where an overview of some of the greatest horticulturists of all time is offered, one of the saddest being E. G. Lodeman who died young, but not before writing another of my favorite books of all time, “The Spraying of Plants” — which I won’t include here because it’s a book that will only appeal to a very small audience (those who want to know about pesticides used before1900).

Best Book on Insect Control — Destructive and Useful Insects is a classic text on insect control which has seen many editions dating back to the 1920s. The best edition, at least in my mind, is the 2nd edition. The second edition of this book was out before the widespread use of DDT and so, while lead arsenate is recommended a little more than I’d like, there are lots of cultural remedies for controlling insect pests listed also.

I’d love to hear about some of your favorite out-of-print books also — anything from general horticulture to plant pathology and entomology — Let me know what your must-haves are!

Rubber mulch rubs me the wrong way

I’ve been receiving a lot of questions about rubber mulch lately. For those of you not familiar with the product, it consists of shredded tires that can be dyed and used on ornamental landscapes or under playground equipment. In fact, the Obamas had this material installed underneath their children’s play structure at the White House. It seems an ideal way to recycle the 290 million scrap tires we generate annually.

But is it?

It’s not effective: One of the main reasons we use mulch is to suppress weeds. Research has demonstrated that organic mulches such as wood chips, straw, and fiber mats control weeds better than rubber mulch.

It burns: You’ve heard stories about piles of scrap tires catching fire and burning for weeks. Well, those same flammable compounds are in rubber mulch, too. When compared to other mulch types, rubber mulch is the most difficult to extinguish once ignited. In fact, some parks and playgrounds no longer use rubber mulch or rubberized surfaces because vandals have figured out that rubber fires cause a LOT of damage.

It breaks down: Although sales literature would have you believe otherwise, rubber is broken down by microbes like any other organic product. Specialized bacterial and fungal species can use rubber as their sole food source. In the degradation process, chemicals in the tires can leach into the surrounding soil or water.

It’s toxic: Research has shown that rubber leachate from car tires can kill entire aquatic communities of algae, zooplankton, snails, and fish. While part of this toxicity may be from the heavy metals (like chromium and zinc) found in tires, it’s also from the chemicals used in making tires. These include 2-mercaptobenzothiazole and polyaromatic hydrocarbons, both known to be hazardous to human and environmental health.

It’s not fun to be around: When rubber mulch gets hot, it stinks. And it can burn your feet. Yuck.

The EPA’s website says this about scrap tires: “Illegal tire dumping pollutes ravines, woods, deserts, and empty lots. For these reasons, most states have passed scrap tire regulations requiring proper management.” So if we have legal tire dumping (in the form of rubber mulch), does that mean it doesn’t pollute anymore?

(You can read a longer discussion on rubber mulches here.)

Whoo hoo!

I promise I’ll post something more substantial today…but I had to pass this email message along that I received this morning. Way to go colleagues and commenters!

Hi Linda,

Your new weblog, the Garden Professors, is an impressive piece of work! I plugged it today in the consumer horticulture CoP blog [http://www.consumerhortcop.wordpress.com].

Regards,

Bill Hoffman
National Program Leader (Ag Homeland Security)
CSREES/USDA