Cutting Up: Pruning Cuts, Reasons and Exceptions

If you get the hankering to study pruning to any extent, you'll find that the opinions are diverse and contradictory.  Using logic helps much of the time, but much of the time the science doesn't seem intuitive, as biology often exemplifies.

There are certainly many cases where the rules apply almost absolutely, but there are almost always some exceptions, so the words "never" and "always" have to be carefully regarded.  There are certain situations where you have to break a rule for the better good, just like if you have to break into someone's home if it's on fire to save their baby, or drive over the speed limit to outrun a racing tornado.

You first need to understand that much of the information out there is dumbed down.  Those who write or teach realize that very few people will get a comprehensive education, so they make it as simple as they can with some rules to follow.  Better safe than sorry.  But most of the time, the finer points are missed or just disregarded.  If you're one of those that just shrugs your shoulders, it's really best to find someone who knows what they're doing.  Once they do what they need to do, then maybe you can do maintenance following their examples.  If your tree hasn't been touched in years, or has been badly pruned, like most trees have, just once, hire an aesthetic pruner who knows what to do.  Well worth it.

TYPES OF CUTS
Generally, you hear about only two types of pruning cuts, thinning and heading.  Well, it's more complicated than that.  Let's go on.....

THINNING is a type of cut where you remove a whole branch.  Can be a huge branch or a tiny branch.  It can be removed to a larger or parent branch, or to the trunk.

This is almost always the preferred cut.  Confusion abounds, where people think that thinning means taking a lot of branches out of the middle of the tree and leaving almost all the branches except for the bare minimum major branches, at the very fringes of the tree.  This is wrong.  I'll explain why a bit later.

HEADING is generally the other cut you hear about.  This is basically when you just cut off the end of a branch or tip of the trunk or main vertical leader.  With anything bigger than a fraction of an inch, these cuts usually look terrible and are ill-advised.  But once in a while, they're the best option or necessary.  In most trees, if you make a heading cut, the end becomes blunt and stays that way, unless a new branch sprouts from that point.  It may or may not depending on the situation. And if it does, it may go off in a weird direction that won't look good.  HOWEVER, if you prune roses, pruning is generally made up of a bunch of heading cuts.  In most trees, heading cuts are almost always avoidable if you follow a yearly proper pruning regimen and never let things get too far.

RE-LEADERING is a term you'll rarely see, and is generally reserved for those who know their stuff.  Consider it a combination heading and thinning cut, from which you'll train a new leader or growing tip.  This is done all the time in bonsai, but in landscape trees it has to be carefully considered.  HOWEVER, if a branch is growing lengthy and lanky, and you want to promote tapering or side branching (ramification), cutting the tip back to a smaller branch or bud that's heading in the right direction would be smart.  In reality re-leadering more like thinning, but back to a branch that either doesn't really exist yet or doesn't quite have enough oomph, even though you know it's there waiting to do its thing.

I use this technique a lot, since I'm very big on proportion and tapering, and re-leadering is frequently the only way to get there.  Since apical dominance is so powerful, sometimes a branch wants to head straight out and never look back.  This conflicts with creating important side branching and can weaken the branch and mess up the proportions.  With re-leadering, you want to avoid cutting anything larger than about 1/2" in most cases, but you need to know what the results will be in any situation.  If it's a huge tree, maybe a bit bigger, say up to an inch or more, and on small trees, maybe 1/4" is a bit too big.  In any case, it's usually smart not to cut back to anything less than 1/3 the diameter of what you're removing.  And it's also best to avoid taking off more than 25% of a given branch, since taking more than that can sometimes lead to die-off, since what's left doesn't have enough vigor, or it can sprout profusely since that removed energy has to go somewhere.

It's best to take out branches before they get to be no larger than about 2" in diameter, since above that thickness requires much more time to callous over.  We're very careful not to use the word "heal", since unlike human skin that eventually becomes just like the original in most cases, think of a branch wound as an injury that remains either an open wound or a scab FOREVER.  Trees are very susceptible to rotting within the branch column under certain conditions.  The larger the wound, the more likely the rot, not to mention the ugliness.  In all fairness, some wounds are actually pretty cool looking if they get a nifty ring around the collar.  In bonsai, these wounds can enhance the apparent age, but these aren't always desirable.  In most cases, it's advised to cut back to a branch that's at least 1/3 the diameter of the branch you remove.

TOPPING is when you simply cut off the top of a leader or trunk, with no regard to how it looks or will respond.  This almost always looks terrible, and unless the tree is about to hit something, or has a bizarre protruding angle, or is dead or diseased, there's no reason to do it.  EXCEPT if someone else has already done it, and in the course of making it right, you actually need to cut it back even more, as is the case with re-murdering Crape Myrtles that have been previously murdered.  People do this a lot with Fruitless Mulberry trees too, and they always look terrible in the dormant season.  No reason exists to do this.  Why have a terrible tree instead of putting a good one in its place, and making sure it fits?

Re-leadering could technically be considered a form of topping if done on a trunk or vertical branch, though refined and with good reason.  So anytime you see it stated that topping is NEVER ok, well, there are some exceptions.  But generally it's a terrible thing to do to anything bigger than maybe 3/4" in diameter.  And you'd better know what the heck you're doing.

LIONTAILING is the practice where people cut most branches out except for a few major ones, and leave almost all the branching at the fringes.  This may actually look ok at a glance, but it eliminates most of the taper which is so important to branches, visually and for strength.  What you really want in most cases is one heavy trunk, a few beefy major scaffold branches, a number of secondary branches coming off of those,  and then finer and finer branches multiplying all the way out to the tips.  There's probably some equation out there that makes sense of how many branches and what size they should be at any point within the tree, but it would be quite variable from tree to tree and always changing as a tree grows.  I really find most people really don't get this, including lots of arborists and nursery growers.  There's an artistic sensibility.  There's also the need to understand how some branches are purely temporary.  You may leave them near the base of a branch to increase bulk at that point, but remove them before the removal scar creates problems.

WATER SPROUTS are almost always to be avoided.  These are the reactionary sprouts that shoot up vertically following pruning or injury, or other stresses, and some will happen with almost no apparent encouragement.  In almost all cases, these are to be removed.  I would sometimes leave these in place if I want to fatten up a branch at that point, and remove them before they're the size of a pencil.  And if you get a bunch of these in the Spring, or after a flush of growth, it's a good idea to rub them off or cut them when they just emerge.  Even if you rub them off, some will re-emege, and it may have to be done several times until the tree settles down.  But in some cases, these sprouts may become a viable secondary branch.  Probably not if they're coming right out of the top of the parent branch.  But I guess a water sprout by definition is really a vertical shoot heading straight up.  You'll see these in most vigorous trees, and perhaps the most obvious is plum trees and birches.  I just pruned a mature Valley Oak that had some, in response to some major (not good) pruning by the utility company to keep a chunk of the tree from messing up phone or power lines.  These companies lack much desire to prune correctly.  They want to spend 1/2 hour removing a big chunk instead of 3 or 4 hours making it look good and equally avoiding the impending entanglement.  My job is now to try to get that tree to balance out better over time.  This will take a long time, since the tree is already at least 50 years old.   But even a compromised Valley Oak is usually a pretty cool tree.

Well, maybe this strayed a bit from the main subject, but these are all connected points.  Hopefully I made some sense out of it.  I'm sure some professionals may disagree a bit on some of the terminology and remedies, but it's mostly dead-on, at least in practice.

I guess the most important thing to take away is, DON'T CUT ANYTHING UNLESS YOU HAVE A GOOD REASON AND A PRETTY GOOD IDEA OF THE REACTION.

TreeDawg out.

Thick at the Base, Thin at the Tip: Trunk and Branch Taper

Taper is one of the most overlooked issues with tree pruning, and perhaps causes the most problems that allow trees to get destroyed by wind or snow.  The problem is that a trunk or heavy branch can't be strong if there's not enough taper, or if there's too much weight only at the ends.  It can't always support the weight it's holding including its own, especially if there's fruit or heavy flowers.  And it really just doesn't look right and shows a history of neglect or improper pruning.  If you want to keep a tree a desired size, at least in the near term, it's imperitive that you encourage tapering so that once it's the desired size you can't go back and start over.  Tapering gives you more options.

The tricky part is determining how much taper there should be.  A trunk and main branches will ever increase in diameter over the years, and you can't stop it.  You can slow it down or speed it up with various techniques.  Eventually, the trunk diameter will be a good proportion to the overall height, but if the taper is lacking, it won't look right no matter what the base diameter.

There are some different patterns that dictate the amount of taper to a degree.  Willows and maples and some birches and various other trees are known to be more slender, so the amount of taper isn't as obvious.  But take a look at an old oak tree, and you'll usually see great taper throughout the tree, unless someone has pruned it incorrectly.  That's one of the reasons the trees look (and are) so strong.  Like a muscleman with thick upper arms, tapering to fairly thin wrists, instead of looking like Popeye.

In bonsai, taper is usually much more encouraged.  Some of these old trees are merely 2 or 3 times as tall as the diameter of the trunk, and the trees look very old and permanent and strong.  I have a little olive tree with about a 3" diameter base that's only about 10" or 12" tall, but I got it that way from a previous bosai grower and frankly the taper is too abrupt and needs refinement.   I strive for a minimum 20 to 1 ratio in all my trees in my collection.  In landscape trees, however, you'll never achieve a ratio of probably 10 to 1 or better in your lifetime, at least not in a good way.

As a very rough estimate, without studying many trees with a tape measure, I would probably see good trunk taper as anything more tapered than about 30 to 1, height to base trunk diameter, and 20 to 1 is really good.  Once again, I wouldn't expect the latter thickness to be common on a Japanese Maple or a Willow, but on more stocky trees, it's something to strive for.  And the taper should really be fairly even all the way to the top, ending at a mere tiny stem at the tip.

Branches wouldn't have this kind of taper, but I would say that in the range of between 30 to 1 and 75 to 1 is pretty good.  But you'll often see trees with almost no taper, and the branches might be 200 to 1!  Pear trees commonly have nearly untapered branches, and this is one of their downsides.  Do what you can to avoid this.

So for a good example, if you have an adolescent ornamental tree that's 20 feet tall, maybe the same width or maybe wider, the trunk should be 8 to 12" in diameter, and thicker as it gets old.  A 3" branch coming off the trunk at about 6' off the ground should be from about 8' long to say 15' long, while keeping it all in proportion (height to width of the tree while tapering of branches thoughout).  This takes some thought and planning and a good aesthetic sense.

Proper pruning will also allow you to control the direction better, and promoting more horizontal branching than vertical is usually better, even in fastigate or upright trees like poplars or liquidambers, some birches, and lots of conifers.

Of course, as you bring a tree home from the nursery, they're usually 6' to 10' tall, with a base diameter of about 3/4" to 1-1/2".  Nobody's gonna wait for great tapering before putting it in the ground.  They want to get the trees in the ground and on their way.  And then they stake the tree so it won't fall over or curve too much, though staking weakens the tree, and in my opinion makes trees grow too perfectly straight.    So it'll take at least 7 to 10 years in most cases before the trees get decent trunks and scaffold branches.  As a side note, remove those stakes as early as you can.  I've seen trees with stakes left in for 20 years or more, with the trunk growing around and devouring the big black rubber band.  That REALLY shows that people paid no attention to their trees after the first couple years.

I'll keep working on this and see if I can get some better numbers and some pictures to demonstrate.  In the meantime, give this some attention when you start to prune a tree.  Strive for even tapering, never blunt tips of long, untapered branches.  Ramification is so important.

Pruning: Goldilocks Style and Father Time

The best pruning takes place when you prune JUST THE RIGHT AMOUNT.  Not too much or too little.

I've had awkward situations with customers and also with friends while helping them prune their trees.  They say either "better stop there", thinking that proper, meticulous, methodical winter pruning is wreaking havoc,  or "take more off" so that it's immediately smaller or thinner, or assumed that taking more off now saves effort in future seasons.

The fact is, almost nobody has managed their trees properly, regardless of how much they've learned or how many trees they look at or who they hired to do the work.  I would estimate that well over 95% of people doing tree trimming, either as a job, a career, or as a DIY or hobby project, are doing it completely wrong.  And once a tree is mismanaged, it only tends to get worse every season.  It's heartbreaking if you really love trees.  And I hate to say it, but the vast majority of people are clueless about what constitutes great pruning other than the most basic rules that don't include the finer points .  Don't look to arborists or tree surgeons or guys that just drive around with a truck, a chain saw and a ladder.  These guys hardly ever get it right.

Think of it this way.  If you get a bad cut on your finger, likely to get infected, leaving it alone would be like not pruning a tree at all.  Cleaning it or putting a Band-Aid on it would be like pruning just a little bit, but not enough.  It needs more.  Cutting off your hand would be like over-pruning.  A bit drastic.  Well, your hand isn't gonna grow back.  A tree, on the other hand, has the potential to grow back to what it should be provided there's proper management forever after, and if you let Father Time do his thing.  However, in many cases, things will never be right, so you either compromise or cut the tree down.

There are certainly cases where taking more off than you might like is needed..  I'll have a posting about Crape Murder and how to solve it, but to make a point here, if your trees have ugly knobs, knuckles, knots, whatever you want to call them, the solution is to remove them and get them started in the right direction, and provided the branches are less than about 2" in diameter, in a few years the tree may actually look normal.  BUT ONLY IF NEARLY PERFECT MANAGEMENT TAKES PLACE.  The actual process may appear drastic, but it's the only way, just like surgery is drastic but can save your life.

If you really want to do it right, have a meeting with the tree trimmer and ask what they're gonna do, exactly why they're gonna do it, and what the results will be now and in future seasons.  Ask them what's the problem to begin with that needs correcting.  They should be able to justify EVERY SINGLE CUT.  Don't let them fool you with keywords and jargon you don't understand.  You should be clear on what's happening.  If they don't make sense, don't hire them.

One really hard thing to understand is that pruning properly one year will mean less pruning in future seasons.  If you spend 3 hours on a tree in a critical year, you only have to spend a fraction of that in each future year.  Once again with Crape Myrtles, you could spend 2 or 3 hours cutting off all the little branches every year and have a really ugly tree for most of the year, or spend about 3 hours in a critical season, maybe another hour or two in the subsequent months, and then each year after that should be much less work, and the tree will look good even during the winter .  Especially if you let the tree grow to its natural height.  If you want to keep it down just a bit, that's gonna take some extra time each year, and not really possible forever unless you want it to be a lollipop.  Of course, if the tree needs a lot of work, the major repairs will need to be done incrementally over a few years   Making an abused or neglected tree look great may take up to 10 years or more, and you may have to live with a "pretty good" tree, not a great one.  But at least not a terrible one. 

Once someone who really knows their stuff gives you an education, you'll never see trees the same way again, and you'll start noticing how badly managed most are.  Have them point out in any given tree how it could be better.

Opinions, however, can be bizarre.  Some people think that clunky, choppy trees with big, swollen, disproportionate sections, vertical shoots and floppy flowers look good.  But then some people thought striped polyester disco jump suits, avocado green refrigerators and first-generation microwave cardboard pizzas were just terrific.

So, Goldilocks, though she was transient and breaking into homes, had it right with the goal of balance.

You too can be a TreeDawg Knight.

Keep Your Hands Off: What NOT to do When Pruning Trees

Every article you read about pruning tells you the same things, like 3-step cuts, leaving branch collars, cutting out crossing branches, removing co-dominant leaders, don't cut more than 1/4 or 1/3, don't cut power lines, your finger or your little brother's finger, don't poke your eye out, etc.  I aim to tell you about things they DON'T tell you.

The ultimate goal with pruning just about any tree is to make it look like it was NEVER pruned, but rather magically grew with proper balance, branching, shape and taper, all without human intervention, all the while looking informal and not like a lollipop or a mushroom.  This achievement of a tree following the rules actually is quite rare in nature, and very, very few people have the skills to make this happen.  Almost every tree you'll ever see has issues, no matter who pruned it or how frequently or infrequently.  Bonsai experts are great at getting this look, ironically with the challenges of keeping the tree less than two feet tall.  Very few tree surgeons, arborists, "expert" pruners or guys that advertise on Craigslist get it just right, usually not even remotely right.  The best situation I come across is when I get a tree that's only a few years old that's been almost untouched, granted the growers usually already start it off on the wrong foot.  They earlier I get my hands on it, the easier I can train it to look great and stay healthy.  Any other condition usually means repairing botched earlier jobs, and a great-looking tree may take years of diligent pruning, but likely will never be close to perfect.

So here are the things almost nobody tells you about good pruning.  You should NOT do these:

1.  ATTAIN WHORLS & KNOBS.  A whorl is a situation when there are more than two branches in one union, or more than one branch coming directly out of the trunk at one point.  With a few exceptions where trees have a natural branching pattern of 3 branches that's hard to overcome, like some conifers, Chinese Pistache, Japanese Maples to a degree, etc., you should strive to have no more than 2 tree members in one spot.  Each joint should look like a peace sign you make with your fingers, more or less.  Plus you look really groovy.  A far worse scenario involves leaving knobs or knuckles at the end of a branch.  This is the result of repeatedly pruning the tip in the same spot, which led to these ugly monstrosities.  They always look terrible and can only be corrected by cutting lower down the branch, which is problematic except in the most vigorous trees.  People have commonly, peculiarly, and horribly mistakenly, decided to do this most frequently with Mulberry trees and Crape Myrtles, and it's a real crime.  Unfortunately, once a whorl is mature, it's usually better to leave it than remove it, since removal will probably be a permanent, obvious blemish, especially if over 2" in diameter.  Sometimes, the decision to remove one or more of the branches is obvious, but often takes great thought.  If there's one of several branches on the inside, it's usually the best one to take out, so the scar will be hidden and it will open up the canopy.  Liontailing is also to be avoided, where all smaller branches are removed from a larger branch except at the very tip.  Not at all sensible.  Also, take a look at almost every tree you pass by.  You'll see almost without exception, one or more branches coming out of the trunk about 6' off the ground.  This is usually done so that people can walk under them, and that's ok, though not always necessary.  Problem is, there's almost always more than one branch coming out in the same spot.
This is a clear no-no, and it creates a giant bulge.  The opposing branches should be staggered and separated by a discernable distance which varies by the size of the tree, thus avoiding various whorls or a huge swollen lump in that section of the tree.  And branches on the same side of the tree should be spaced appropriately, which will also vary.  It takes a keen eye to determine the right distance apart.  Nature determines much of that by node spacing.

2.  LEAVING STRAIGHT, UNTAPERED BRANCHES.  Branches in most trees naturally tend to taper noticeably, and usually don't keep going straight, but either curve or branch off in a slight direction, or divide into two or more smaller branches..  A lack of taper doesn't look right, but it also means the branch is probably too heavy at the end, and probaby too big in relation to the scale of the trunk or the overall tree.  This is common where someone either removed most of the secondary branches from the larger branch, or just let it grow too long, possibly while cutting some of the upper trunk.  Since growth is more vigorous at the tip, it lets girth accumulate faster toward the tip.  There's no exact formula, but a guideline is to avoid a branch being more than half the diameter of the trunk at the point of attachment.  Taking care of all this takes good diligence and ability to figure out how the tree is likely to grow.  Pay attention to oak trees in the wild.  They have curving, tapering branches and usually no whorls, and look fantastic.  They would l look even better if they were meticulously pruned all their lives.

3.  INFREQUENT PRUNING
The best scenario is to do more minor pruning more often, several times per year at crucial points, rather than once every year or every few years.  It shouldn't end up being a lot more work in the end, because every cut you make should help avoid multiple problems later.  More later....

4.  PRUNING THE WRONG TIME OF YEAR
You'll find all sorts of opinions on when to prune this or that.  It's seemingly quite complicated, and opinions on all sides are somewhat valid, even at opposite points of view .  After extensive research, I determined the only way to figure it out is to look at each specie separately, use a bunch of logic and experience, and determine the actual objective for each pruning session.  I'll have another post dedicated to all the specifics, which should clear all the confusion.  In any case, probably the worst times to prune are between September and late November/early December, but this can vary with climate, specie, and the objective at hand.   More later.....