It is deciduous, but considered a 4 season plant mainly because:

• It has lush dark green leaves.

• It flowers white in early summer.

• It has bright yellow fall color and cinnamon colored exfoliating bark.

As you can see it’s a great plant, but you need to be aware of its capabilities.

The first year or two it grows slow while it establishes. Then the pace picks up and it becomes quite vigorous.

As a climber I’ve yet to see its limit in height. Planted at the base of a large tree it will cling and climb until it reaches the top. I’m talking 60′ no problem.

The good news is you can control climbing hydrangea with proper pruning. But I say that with a warning.  If you use it in a limited space, like the one we’re about to talk about, you must be diligent with your pruning or it will easily take over the area.

It’s Doing Well – Too Well!

How do you respond to a customer that says that to you?

“I’m glad your climbing hydrangea is doing well, but sorry it’s covering your house.”

You can avoid those embarassing moments by knowing a plant’s capability right from the start.  Then you can advise your customer what to expect, how they can care for it or how others will care for it.

In the picture above climbing hydrangea is working well on this brick wall. But the plant wants to get bigger, as it does every year. It’s in its DNA.

Notice that the real dominant growth is towards the top. It wants to climb and get as tall as it can. I’ve used climbing hydrangea on homes where it is maintained just below the second story eaves. Not easy to do, but the look is beautiful.

How To Go About Controlling This Climber

The best time to prune climbing hydrangea is after it flowers.

The new flower buds are formed soon after flowering and remain on those stems for the following year. So you’d rather not cut those off if possible.

However, unless you operate with a “calendar of tasks” for your maintenance accounts, you will most likely prune the hydrangea when you’re there pruning everything else.

So regardless of when you prune climbing hydrangea, cut back the long shoots and those growing outward from the wall to just above a bud or leaf point. Prune selectively using hand pruners.

Often I’ll follow an aggressively growing branch to its “point of origin” and make my cut there.  This is the point where the lateral branch connects to a larger stem.

This climber produces “aerial roots” that attach themselves to whatever structure is nearby. When first planted you may have to help it attach to the structure by:

• Installing the plant so it deliberately leans and touches the wall or structure.

• Tying some of the main branches to the wall or structure temporarily till they attach. Several materials and methods will do this, but be careful these ties don’t constrict around the branches.

These aerial roots will sometimes leave a mark and organic residue on the surface after they attach. On this home some of the branches attached to the white shutters. It took extra time and effort to scrub them clean.

Like with all plants, when you know and understand their characteristics you can use them creatively and effectively. How have you used climbing hydrangea in your landscapes?  Did it perform as you expected or surprise you?  Let us know in the comments.

Canker On The Trunk Of Japanese Maple

These disease causing agents are either fungi or bacteria.

Fungi reproduce by spores, and these spores are the main way a fungus spreads to new hosts. These spores will travel through the air. Once a fungal spore lands on a plant, it lies dormant until conditions are suitable for it to infect the plant. Moisture is a key ingredient for fungus to develop.  You’re probably also aware of this for turf fungi.

Many plant fungi can survive in the soil or on plant debris, whereas bacteria pretty much hangs out just on infected plant debris. This is why it’s good practice to clean up fallen leaves from infected plants and discard them in the trash.

The fungus or bacteria can enter the plant either through a “wound” or even through natural openings. One type of natural opening, and maybe you’re familiar with the term, would be stomata. These are the tiny openings on the underside of leaves.

Wounds Are An Open Invitation To Disease

A plant’s bark is just like our skin. It protects the “innards” from outside harmful things. When an opening occurs the plant becomes vulnerable.

The canker is obvious in the picture of the maple trunk. Michael Hirsch, our plant health care adviser, says the canker developed because a pathogen found its way into a wound at the trunk.

It’s very likely this wound or “split” in the bark occurred from sunscald. This splitting of the bark happens usually in late winter or early spring when severe cold is followed by a quick thaw. Also, sunscald is usually seen on the west side of the plant where afternoon sun causes the thaw.

To protect against sunscald and the wounds it creates you can wrap the trunk with paper tree wrap in late fall. Just remember to remove the wrap in the spring because insects and other organisms can develop and wreak havoc under there.

It’s also a good idea to shape the the wound into an “ellipse” using a sharp knife. Cornell University has a great short article on bark splitting on trees with recommendations on how to deal with them.

Wounds can certainly be caused by other things besides sunscald.

Most wounds in the landscape are man-made. Examples are: poor pruning cuts, damage from improper handling and planting, lawn equipment, etc.  Sometimes animals like rodents and even deer cause damage.

What Can Be Done

There are some proactive things you can do to minimize tree wounding. You know I’m going to say practice good pruning and plant handling techniques, but also install adequate mulch rings around trees to avoid mower and line-trimmer damage. Mike Hirsch also recommends using tree wrap for a short while on a new wound to help prevent a pathogen from settling in. Once callusing starts you can remove the wrap.

In many cases canker will not kill the tree, but could structurally weaken it and its ability to cope in the years to come.

Mike oversees the plant health care on many of my projects. And although he’s always there to diagnose and advise, clients rely on him to not just treat the symptom but discover why these problems are happening. Every landscape contracting business should have a plant health care specialist on staff or one within there network.

When I use the term “core” I’m referring to the center of the plant’s root ball.  A nursery plant that’s been dug, balled & burlapped (B&B) is now totally reliant on that root ball to keep it alive.

One of the major concerns of everyone handling and caring for that plant should be to keep the root ball adequately moist all the way through to its center or “core”.

Here’s why that’s so important.  Undoubtedly all nursery plants will have their “ups and downs” with moisture availability due to varying conditions and circumstances.  Typically the root ball will begin to dry on the exterior.  If moisture is not provided, the dryness will continue towards the center.

If the dryness travels too far into the root ball:

1. In all likelihood the plant will be severely stressed and damage will occur.
2. Restoring moisture back “to the center” of the root ball can be slow and difficult.

The trick is to not let the root ball get to that point.

If you watch and monitor the moisture levels of your nursery plants (whether they’re above ground or planted) :

• It’s easier to maintain consistent moisture throughout the root ball.  Dry soil can become “hydrophobic,” making it very hard to re-wet.

• You avoid plant stress that could be irreversible.  Yes plants often bounce back from early stages of dryness, but if the dryness is prolonged and represents drying “to the core” it’s not good.

How To Maintain Moisture Levels

Consistency is the name of the game.  If the nursery plant is being stored above ground, it is that much more challenging because the root ball is exposed to sun & wind.  Whether you’re watering by hand, sprinklers or a drip system designed for nursery stock, be vigilant.

If the tree has been planted, consistency is still key, but being in the ground helps tremendously (no pun intended).  The earth protects the root ball and insulates to help moderate temps. and slow moisture loss.  Still, the plant is losing moisture through its leaves (transpiration) and the soil is gradually draining & drying.

Sprinklers will work  for the most part, but again, consistency is key.  The watering must work its way from the surface down to the “core” of the root ball.  With a steady watering schedule the moisture level should be maintained through all the soil levels.

Sod staples hold pipe to the ground

During these hot summer months in particular, we’ve been using 2 watering methods to ensure our larger, recently installed plants are kept moist “to the core”.

The pictures above show basic, store-bought soaker hose being used.  I’ve coiled a 50′ length around the base of this newly planted tree using sod staples to hold the hose down.

The root ball on this plant is 42″ wide.  It’s imperative this tree stay moist to the center of the root ball.

Every few days the homeowner connects a regular water hose to the soaker and lets it run for just 10 minutes.  We found that this schedule during this hot, dry weather is adequate to keep the root ball moist.

The other method we use is the “Treegator”.  The one in the picture holds 20 gals. of water.  It’s designed with a zipper from top to bottom so you can wrap it around the trunk.

Treegator

With the Treegator the concept is that the water-bag (or reservoir) be filled with a hose and then allowed to drain gradually by itself.  It can take several hours for the bag to empty.

Both these methods concentrate water directly over the root ball where it can seep in without much “runoff”.

I should mention that it’s equally important to monitor the moisture levels below the ground while these watering methods are being used.  Keeping the plant moist is important, but “over-watering” can have damaging affects on plants.

Irrigation is such an important part of plant health and it seems the least understood.  I’m going to continue to write about it in the hopes that this basic fundamental of plant care is better understood and practiced.

There are so many “tricks of the trade” and techniques for watering.  If you have one I’d love to hear about it in the comments.

Euonymus ‘Emerald Gaiety’ and ‘Emerald Gold’ are 2 very common shrubs.  In many ways the two are similar in form.  You’ll often see both used as a low, mounded shrub either at the front of a garden or as an area groundcover.

Euonymus ‘Emerald Gaiety’ has the distinct capability to climb when planted next to a structure.

In this first picture is ‘Emerald Gaiety’ and further down the stone wall   is ‘Emerald Gold’.

The loose, straggley growth on top is typical and perhaps in a larger open space this “wildness” would be OK.  For example, used on a slope as a groundcover this “rambling” habit would be great.

However, in other gardens  you may want to prune for a neater look.  In this situation the Euonymus ‘Emerald Gaiety’ is overpowering the azalea behind it.  Let’s bring it back to scale, but keep that natural form.

How To Prune

As always, the best method of pruning any plant to maintain a “natural” appearance is to prune “selectively” – that is, by hand, single cuts with hand pruners.

Some of you are probably saying, “Are you kidding, I have too many to prune selectively”.  I hear you.  There’s a point of practicality where you have to make a judgement call.  In this case it’s not the end of the world if you shear the plants to make a monstrous task more doable.

These next 2 pictures show selective pruning on the Euonymus ‘Emerald Gold’.  I pruned the ‘Emerald Gaiety’ the same way.

Select the longest growth that extends beyond the main body of the plant and follow it down into the plant.  There, among the denser growth make your cut just above a leaf or lateral branch.

This last picture shows the Euonymus ‘Emerald Gaiety’ after it was pruned selectively. Notice how the “natural” form was maintained, but the plant is neater and more in scale with the azalea behind it.

To Shear or Not To Shear

With Boxwood most people instinctively shear the plant.  The vision most of us have is one of perfectly shaped forms.  It definitely is at the top of the list when it comes to formal gardens and topiary.

I’d like to suggest two circumstances when “selective” pruning might be the alternative to shearing.

1. when boxwood is used in “natural, informal gardens”.
2. when boxwood starts to decline because of too dense branching at the outer ends of the main stems.

Boxwood used in natural, informal gardens.

It’s such a reliable, solid performer; I often use boxwood in natural settings.  In these gardens the boxwood are pruned selectively by hand to encourage the plant to stay full and strong while keeping a soft, mounded shape.

Dense, outer growth causes decline.

Overtime a constantly sheared (and formal) boxwood can start to decline in health.  This could be because of a number of conditions, e.g. poor internal air circulation that could promote disease or insect infestation.  The fact is plants naturally are not conditioned to have all their foliage concentrated just on the outer portion of the branches.

To improve or maintain the health of a sheared plant, you can selectively prune out a portion of the dense, outer growth.  If done right this will allow more light and air into the interior without causing a dramatic change in the look of the plant.

Topiary Boxwood

I’d like to focus on shearing because this is by far the most common way people prune boxwood.

These first 2 pictures show the before and after of a Boxwood ‘Wintergem’ that was sheared.

This is a recently planted boxwood that was sized at 24 – 30″.   At this young stage you have the perfect opportunity to set the proper shape for the future of this plant.  Although you can often correct misshaped plants, it’s not easy and usually takes 2 to 3 seasons of growth to see improvement.

The fundamental rule in shaping a plant is wider at the base and taper towards the top.  There are 2 main reasons for this:

1. It’s healthier for the plant because light is better distributed to the foliage.
2. Aesthetically it’s more attractive and logical that the plant be wider at the base.  You want the plant to appear as though it’s connected and well-anchored to the ground.

In the sketch below I give a couple of typical shapes you would shear plants both the “right” and “wrong” way.

It is not easy to develop these proper shapes with wider bases.  Plants naturally grow a little weaker and thinner towards the bottom.  Also, it’s been my experience that most people want to cut an equal amount off the plant all over.  That doesn’t work!

If you look at the first picture of the unsheared boxwood, notice how the greater amount of growth is concentrated towards the top.  The bottom and lower sides naturally have less growth.  Now look at the plant sheared in the 2nd picture.  The lower portion of the plant was not touched by the shears.

I still happen to use a pair of hand shears for trimming topiary plants.

You should develop a system or pattern to how you shear a plant, get good at it, and then repeat that pattern from plant to plant.

I shear plants in a clock-wise direction.  I imagine the proper line the shrub should have and follow it.  Regardless of how much or how little foliage there is, stay on that imaginary line. If you need a little help and guidance, for the straight lines take a length of wood like a 1 X 2″ (or anything like that).  If you just hold it up once in a while to show the line you’re trying to create, it can really help guide you.

You more often see power hedge trimmers today for shearing topiary plants.  They are powerful and quick.  If kept sharp and in skilled hands they can do some nice work very productively. In unskilled hands…I’d rather not talk about it.

When to shear plants.

Generally it’s best to let the new growth finish and “harden off” a bit before shearing.  From a practical sense the plant should not grow much (if at all) after that and the shape should stay nice until the following growth season.

If you happen to trim early, occasionally I have seen new, soft growth scorch a bit if the weather got hot right after the shearing.

On some properties plants might be sheared twice because the owner does not want to wait for the growth stage to completely finish.  So it’s done perhaps midway during growth and then again when it’s finally finished.

These are the main considerations when pruning boxwood and many of these points apply to other plants as well.  However, it’s so important you consider each plant and their “specific” preferences and requirements.  Like so many things, the skill starts with the right knowledge.

Just what are reverted shoots?

Many of the unusual cultivars of plants you see came from the original, normal plant.  What happens is a mutation occurs in the normal plant causing an unusual (and sometimes desirable) variation of growth.  For example, the shape of the mutated growth might be compacted or miniature compared to the normal plant.

If the growth and/or color traits of the mutated shoot are desirable, then more plants can potentially be created from this shoot.  This is done by “vegetative” propagation.  In other words cuttings are taken from the unusual shoot and rooted to make young plants.

Over time a shoot of growth may appear on this new “cultivar” that has the plain foliage from the original normal plant.  This is a “reverted shoot”.

What to do with them.

Whenever you come across a reverted shoot on a variegated or unusual foliage plant, it should be removed.  Not only do they look out of place on the unusual cultivar, but they will start to dominate the plant.

As you see in the picture below, prune the reverted shoot right at the point of origin.

One of the most common examples of branch reversion is with Alberta Spruce and perhaps you’ve seen it too.  This compact plant is derived from the standard White Spruce.  A reverted shoot on Alberta Spruce is not hard to identify.

Pruning Time For Flowering Plants Is Important

Homeowners will often select a plant because of the exceptional bloom it has.  They’ll look forward to it all year.  But Mrs. Gotrocks is really bummed this spring.  Her azalea has hardly bloomed at all.

Hmmm.  Plant looks nice and healthy.  Good color in the leaves, and it does get fed each year.

Fact: A plant will not flower without a “flower bud”.

This plant is just fine – it couldn’t be healthier.  Problem: Its flowering cycle is being interrupted.

In the spring the azalea should flower following its normal schedule.  Soon after flowering it begins to produce the flower buds for next year’s bloom. What’s happening here is the azalea is being pruned too late in the season and the flower buds for next year are being cut off in the process.

Azaleas, like other flowering plants, have a “cycle” they follow through the year.  It’s important to know this cycle and when the plant develops flower buds, before you prune.

When You Prune Is As Important As How You Prune

Being aware of the different plants on your property and knowing their cycle is great information to have.  You can then note the plants that will need pruning and schedule it at the right time.

These azaleas (see pic above) are well spaced and have room to grow.  That’s a plus right from the start.  I would not be anxious to prune these plants, but rather let them grow naturally.  Their beauty lies in their natural form.  Also, they’ll flower beautifully each year with their flower buds intact.

Azalea incorrectly pruned by shearing.

What if the azalea needs to be pruned?

You can preserve the “natural” look of the azalea by selectively pruning the faster growing, dominant branches.  Make these individual cuts with a hand pruner just above leaves and/or junction points where branches connect.

Time this pruning soon after the azalea has finished blooming.  This way the plant can then go about producing its flower buds for next year without having them cut off later in the season.

The last picture here shows an azalea close-up that was sheared rather than selectively pruned.  You can see both leaves and stems cut randomly by the general path of the shear.  Not only is this unhealthy for the plant, but it also looks like %$&@.

Isn’t it amazing how different plants can be from one another?  We really need to know and understand these differences because in the finished landscape we’re trying to manage what should be the natural cycles of these plants.

I’m always here to help.  If you have a question or comment feel free to enter it below.

This group of “low junipers” is often either not pruned or pruned incorrectly.  Not pruning can result in run-away growth where these junipers outgrow their space.  Incorrect pruning can alter the plant’s natural growth habit and cause it’s health to decline.

How Do They Naturally Grow?

Right?…This is the first thing to ask yourself before pruning.  The cuts you make should support the natural growth habit and shape of the plant.

Low, spreading junipers naturally want to grow horizontally and get much wider than tall.  Their branches shoot out; instinctively wanting to dominate and get longer (this is known as apical dominance…you don’t really have to know this).    In a wide open space where you’re looking for maximum coverage, this growth habit is ideal.  In these circumstances you can allow the plant “to do its thing”.

Often, however, low junipers are used in limited spaces.   If left unchecked, they’ll out-grow that space and, well…the solutions to that are not pretty.

Selectively Prune

Selective pruning, as you probably know, is time consuming.  As the name implies you are selectively choosing where on the plant to make each cut.

There is no power equipment that significantly automates this process.  There are some people that “shear” these plants with power shears.  That’s incorrect and a disaster as it turns them into manicured shapes and promotes dense growth only on the ends of the branches.

In the second picture above I’m choosing branch ends that are growing noticeably faster and longer.  I then move down the branch to a point within the secondary, slower growth – and make the cut.  This is done throughout the plant.  Try to work from one area out and not jump around randomly.  Always be conscious of the plant’s natural shape. Step back occasionally to check  your work and adjust your cuts if necessary.

The first picture above shows a newly planted Juniper ‘Parsoni’.  The shape of this new, low, spreading juniper is misleading.  Notice how the side growth is somewhat stunted as compared to the top growth.  This is because this plant is coming from a nursery where it had been stored in close groups – probably almost touching one another.

The last picture is a low, spreading juniper that was just “selectively” pruned. (Click on it for a bigger image.)  Most of the long ends have been pruned back, and the natural shape preserved.

Your low, spreading juniper will have a long, beautiful life if you prune them “selectively”.  Of course,  remember how equally important spacing them correctly is when planting.

The Green Giant’s Growth Habit

Perhaps I’ve said it before, but it’s extremely helpful when you know what a plant’s growth habit is before you prune.  Growth habit is basically the shape a plant naturally wants to grow into and how the branching structure supports that shape.  For example: Arborvitae ‘Green Giant’ is pyramidal in form and proportionately much taller than wide.  As a matter of fact, this plant will easily get to 30′ tall and 15′ wide in thirty years.  Rapid grower…I think so.  Its branching structure is horizontal with some ascending branches as well.

Other characteristics about the plant can be helpful too when deciding your pruning strategy.  For instance, Arborvitae ‘Green Giant’ prefers more light (full sun is ideal).   The less light it gets the thinner and more open its branching and foliage will be.  Prune less aggressively if you know the plant is adapting to less than ideal conditions.

Before Pruning

The Pruning Strategy

Let’s assume the ‘Green Giant’ you’re going to prune has been positioned to have enough room to grow and stay somewhat within its “natural boundaries”.  If the space is too limited and there’s no future for the plant in that spot, think about transplanting it.

To give ‘Green Giant’ a strong trunk and branching structure, it’s important to prune them in their early years.  In the first picture above, these Arbs were undoubtedly pruned early on in their lives.  Notice how full they are from the ground to about 4/5ths of their height.  However, the last growth at the top is thin and “stretched-out”.  This is very typical of rapid-growth plants.

It is this top growth (upper 1/5th) that needs pruning.  You should also scout the lower portion of the plant for any branch ends that may have grown more aggressively than others.  There should not be many.

After Pruning

I apologize for the picture quality of these “before” and “after” shots, but even the silhouette conveys the degree of pruning I did.

I used a traditional trimming shear along with an orchard ladder.  By today’s standards you might call that “old school”.  I still think a good quality hand shear gives the best cut and, of course, with total control.  I did, however, think how convenient and productive a telescopic gas powered shear would have been.  Just take care as those power shears can cut aggressively.

The main goal and concept here is to trim the ends of the longer, fast growing branches to shape the plant and encourage fuller growth.

This is what plant nurseries do while they’re growing the plants for market.  You want to continue this trimming routine for as long as it is practical.  The idea is to develop a full, nicely shaped plant so that it can continue to grow on its own with this strong foundation you’ve help create.

I’d like to share with you a symptom that a standard flowering dogwood was showing.  The tree is about 16′ tall and was transplanted on a project of mine about a year ago.

The  time of year was summer and I noticed the leaves were off-color with some of them dropping.  The tree had been doing well for months after being transplanted.

From experience I knew “a look” like this often means plant stress due to some impact on the root system.  Although a root system can be affected by a variety of insects and diseases, the first thing I check for is water damage.  Roots kept too wet will decline and die and, eventually, so will the entire plant.  The gauge on the soil moisture probe verified extremely wet ground down by the roots.  But that was only part of the problem.

Michael Hirsch, our plant health care consultant, emphasizes the importance of removing the heavy burlap from the top of the root ball.  If left on the plant it creates an unhealthy environment where disease and insects can develop.  It also keeps the base of the trunk damp, which isn’t good either.

It was time to give this tree a break and get conditions back in its favor.

After pulling back the mulch I cut the sisal cord and removed all of the burlap. It was heavy, wet and semi-decomposed.  Underneath it all was a collection of insects that would have gotten any entomologist hot under the collar.  This had not been a good environment for this tree.

I have to believe this tree felt immediately better once all that crap was removed.  Just look at the dampness in the bark where the burlap was.

I was also careful to replace just a 2 to 3″ layer of mulch on the surface and not up against the trunk.

What remained to solve was the wet ground this plant was struggling in.  Phases of this project were still underway and the sprinkler system had not yet been modified.  When I checked out the zones around the tree I discovered:

1. The planting bed zone where the tree was planted was cycling every 3 days.  Way, way too much.
2. On top of the watering from the planting bed zone, the lawn zone was not adjusted for the re-designed area and was actually soaking the tree too.  Talk about the “1 -2 punch”!

With the burlap “choke collar” removed and the irrigation fixed, (I shut the planting bed zone completely off, and adjusted the lawn heads to not hit the plantings), this dogwood now had a chance to recover.

It was summer when this tree started failing.  It is now October and the dogwood is doing fine.  The leaf drop stopped, color improved, and moisture levels in the ground are “normal”.

Plants are living things, and just like us they need the right conditions to remain healthy.  When you see a plant struggling first look to see what nearby conditions might be “extreme” and/or different from what this plant would normally grow in – that’s the essence of “plant health care”.