Gardening Tips 3/15/13: Pruning Crape Myrtles

And now, my Gardening Tips article from the Roanoke Rapids Daily Herald!  This week's article is Pruning Crape Myrtles, which I guess has been the theme of the blog for this week, but this is my last word on the topic for now.  I will be back soon with something completely different, I promise.

http://www.rrdailyherald.com/opinion/columns/gardening-tips-pruning-crape-myrtles/article_991c8bda-8d9a-11e2-8369-001a4bcf887a.html

Creating an instructional video (Pruning Crape Myrtles) Part Two

Before I get to the video itself, I want to share a couple quick thoughts on the making of the video.  Since the impetus for doing this was a class assignment, and this is the first time I've made this type of video and the first time I've posted anything to YouTube, this reflection seems appropriate.  However, if all you care about is learning how to prune your Crape Myrtles, I won't be terribly offended if you skip the next few paragraphs. 

First, I spent a lot of time thinking about the points I wanted to make during the video ahead of time, but I also wanted to appear natural on camera and not read from a script, so there were a few things I forgot as we were filming (I'll fill in the gaps below) and I stumbled over my words a time or two.  We also shot a few takes, on a few different trees, and since each tree was a little bit different some points were stressed less in the final video then they were on other takes.   Overall, however, I'm pretty happy with the information presented. 

Second, I spent a lot of time in my head planning how I wanted the video to look, but not a lot of time sharing that plan with the person who shot the video, my wife.  So there are a few times when I wish the camera was focused a bit more on the tree or the branch I was cutting and a little bit less on me, but I have only myself to blame for that.

Finally, I waited and waited for a day when the sun was out and the weather was warm and the wind was calm (as calm as it ever is in March anyway), and I ended up settling on a great day weather wise.  I forgot, however, that all of the trees I had at my disposal as pruning examples were in fairly close proximity to the road, meaning that there's some car noise here and there.  I tried to pause when cars went by so we could edit that out as much as possible, but I'm not perfect. 

So, I've posted the video below and I hope it gives you a good understanding of how to prune Crape Myrtles.  The main points I want you to take away from the video and these past two blog posts are:

1. Prune to enhance the natural shape of the tree, not to change it.  When you're finished pruning, the tree should like like a neater version of the tree you started with, not a different tree entirely.

2. Remove low growing branches to expose the trunks, and selectively thin the top half of the tree to prevent the canopy from becoming too dense.  Branches that are dead, damaged, crossing one another, or touching one another should be removed.

3. Remove excess trunks early in the tree's life so that it more closely resembles a tree than a bush.  3-5 trunks is ideal.  For older trees, it is not always practical to remove trunks, so you may have to make do with what you've got. 

4. Above all, resist the temptation to hack Crape Myrtles down to the ground year after year as so many people do.  If you haven't already, read my previous post where I outline why Crape Myrtles are so often pruned improperly and how this is harmful. 

Finally, please feel free to leave comments here so I know what other topics you are interested in.  I may not be able to make a video or write a blog for each one, but I can certainly make sure your question answered.  Thanks for reading. 

Creating an instructional video (Pruning Crape Myrtles) Part One

One of the assignments I need to complete for my technology class is to create a video for YouTube that I would use to enhance an extension training.  The first thought that came to mind regarding this assignment was that I should create a video on how to prune.  Many questions that I get, particularly this time of year, revolve around pruning. Grapevines, fruit trees, and Crape Myrtles are the plants most commonly asked about.  Unfortunately, pruning techniques are difficult to explain over the telephone and using pictures and diagrams don't always help all that much.  I have held pruning workshops and have gone to many people's homes to do pruning demonstrations, but it is hard to reach everyone this way and so I thought that a good instructional video would be very helpful. 

Crape Myrtles seem to be a good place to start. Nothing, and I mean nothing, riles up a horticulture agent like the topic of pruning Crape Myrtles.  By and large people seem to have no logical idea of how to prune these trees, and yet, bizarrely, they are convinced, aggressively so, that they absolutely must be pruned.  Well maintained Crape Myrtles are beautiful in bloom, have a unique and elegant shape, and many varieties have stunning, exfoliating bark that gives their trunks a dazzling multicolor appearance.  When Crape Myrtles are pruned drastically, the way they often are, it sabotages both their natural shape and their exfoliating habit, creating trees that are, at best, bland, and at worst an outright eyesore but for the few weeks they are in bloom.   Forget the blooms- Crape Myrtles are going to flower either way- but would you rather have a Crape Myrtle that looks like the one at the top of the page with cinnamon-colored bark on their smooth, solid trunks or like the one on the left below with weak, grayish, knobby trunks, or the one on the right with a mass of thin, overgrown, flimsy branches?  It's all determined by how they are pruned.

I think I understand why people are confused about how to prune crape myrtles- they are a tree, one that will grow anywhere from 10-25 feet tall depending on species, yet they don't have a single trunk like most trees do; instead they have multiple trunks like a shrub.  So this alone creates some understandable confusion.  What I haven't figured out is why people massacre these trees year after year the way they do, cutting them back to within a few feet of their lives, something no one in there right mind would ever do to any other type of tree.  I've narrowed it down to a few theories, and perhaps each of these is true in at least some cases.

#1) People prune crape myrtles back because they become much larger than expected.

This is something that happens with a number of plants.  When they are initially planted, by a gardener or a landscaper, their final size is underestimated, so as they mature, we find they become too close to other plants or too close to a building or structure, and our impulse is to chop the plant down and make it start over.  While I can follow the train of thought here, it's not horticulturally sound.  Pruning may immediately reduce the size of a plant, but it also encourages growth, meaning it won't be long until the plant returns to the size it was.  In fact, the more you cut a plant back, the faster it will grow back, so severely cutting back a plant like a Crape Myrtle is the very definition of a temporary solution. What does often change, permanently so, is the plant's natural shape.  In the case of Crape Myrtles that have been drastically pruned, they no longer form a vase or umbrella shape, but rather become a thick of mass of rather unappealing vertical growth. 

#2) People prune crape myrtles back because they believe this will increase their bloom in the coming year.

While this point is rooted in some amount of truth, it does not justify the level of hackery Crape Myrtles are often subjected to.  It is true, they do bloom on new growth, like many other late summer blooming plants.  However, it is not necessary to prune them so drastically in order to produce the amount of new growth needed to produce sufficient bloom.  Let's try a quick numbers based analysis.  Many crape myrtles in our area have an approximate size of about 10 feet.  These same trees are often cut back to about 4 feet high in the winter time.  This pruning leads to a flush of new vegetative growth, anywhere from 2 to 6 feet as the plant works furiously to recover to it's former size.  New blooms won't be produced on all of this new growth, rather the blooms will always be most prominent at the very tips of each branch.  So, why do we need to prune these trees so that 6 feet of new growth is produced each year, when only 6 inches of that new growth will produce blooms?  The answer is simple- we don't.

#3 People prune crape myrtles the way they do because they see their neighbors doing it and they think that must be how it's done. 

While there is no way to say for sure, I think this is the most likely reason people prune Crape Myrtles the way they do.  When we don't know how to do something, we often look to others for help.  Naturally if you have a Crape Myrtle tree you are not quite sure what to do with and you see all your neighbors pruning their Crape Myrtle trees a certain way, you're probably going to assume that whatever they are doing is the right thing.  It's easier to mimic what you see everyone else doing than it is to search out the right way to do it.  Unfortunately in this case, the people who prune their Crape Myrtles improperly seem to be in the majority. 

So how should they be pruned?  Well now that the weather is warm enough and the wind isn't blowing quite so hard, I plan to go outside today and film a quick instructional video that will show you exactly how to prune.  Check back here for tomorrow to see the video.