Why bother having trees?

Sorry to be late with my post this week – I was away reviewing grant proposals.  It was interesting and useful work, but really drains your brain.  So with that being said, my post is long on pictures and short on words.

One of the things that bugs us GP types is poor plant placement.  Why bother planting a tree if you’re not going to allow it to grow naturally?  Here are some photos to mull over the weekend.  While I have lots of bad pruning pictures, these ones are chosen specifically because the trees were obviously poor choices for either site usage or size.

Because my sense of humor seems to have been left at the grant reviewing venue, I can’t think of amusing captions for these pictures.  But I’ll bet you can!  Just submit them in the comments sections, and I’ll repost the photos later next week with your contributions.

Photo #1

Photo #2

Photo #3

Photo #4

Photo #5

The importance of knowing your plants

One of the first courses a horticulture student takes is plant materials, or, in the case of a forestry student, dendrology.  Why?  Pretty simple; it’s hard to select plants if you don’t know what they are and what they’ll do in the landscape. Of course, the classic example is a large tree or shrub planted in a tight spot that eventually devours an entire house.  But we usually don’t have to look too far to find situations where a homeowner or landscaper clearly had no idea what plant he or she was dealing with.  To wit, a couple of recent examples of poor plant choices (maybe this can be our next series after “Why do nurseries still grow THAT?”)

I spotted the first example wandering through downtown in my hometown of Olympia, WA.  At first glace it looks like an ordinary hedge; boxy to by sure, but nothing remarkable.

As I passed by though I noticed the hedge was actually a weeping Norway spruce (Picea abies ‘pendula’ – actually it could have been an ‘inversa’ – the repeated butchering made it hard to tell).  Either way, what could have otherwise been a fairly interesting plant had been reduced to a squared-off blob of blech.  The other side, of course, is that if a squared off blob of blech is truly desired there are cheaper and easier ways to achieve the effect.

The other example of the perils of not knowing your plant material comes from northern Michigan.   This case represents that other extreme of trees that grow too large for their space.  Here the homeowner wanted to screen his house (on the left but out of camera range to protect the guilty!) from the railroad track on the right of the photo.  Solution: Plant some conifers! Sounds like a good idea to me.

Only problem – the owner chose to plant the screen with dwarf Alberta spruces!  As with the blob of blech, the property owner could have achieved the desired screen in a couple of years and at a small fraction of the cost with seedlings from their local conservation district or seedling nursery.  In any event, we’ll check back in about 40 years and see how it’s working out for them…


A Taraxacum teaser

It’s spring and the dandelions are happy to see you!  I’ve taken photos of two groups of dandelions just footsteps away from one another. The populations are both in full sun, with similar types of soil and water availability. You’ll note that one group has very short flower stalks, while the second has longer stalks:

So what’s responsible for the difference in flower stalk length?  And for extra credit, what’s the scientific term for the phenomenon?

If this isn’t something you’ve noticed before, you will from now on!  Answers Monday!

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