Pruning With A Purpose

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Pruning woody shrubs, when done properly, is good for the plants.  Cutting out dead or diseased branches helps to preserve the overall health of the plant. Branches that cross over one another may damage the bark of both branches.  Damage to the bark of a woody shrub is an invitation to insects and disease.  Thinning out a woody shrub can help to maintain it at a desired size for many years.  That thinning allows light and air to penetrate the interior spaces, keeping the interior of the shrub well foliated.  In the hydrangea hedge above, the upper branches were kept long, a practice which eventually shaded the lower branches.  The lower branches have leaves that are smaller, and fewer flowers. Once we started pruning these hydrangeas, we shortened the top branches considerably and unequally, and pruned the lower branches with the idea of encouraging lateral growth.  Ideally, a hydrangea should be wider at the bottom than the top.

limelights 2013 (7)As an experiment, I did not prune my limelights at home at all last spring, but for removing the spent flower heads. My reason?  I have a yew hedge in front of them.  I wanted my hydangeas to grow tall, and have lots of blooms in the top third of the plant. On the inside of this hedge is a boxwood hedge, planted fairly close to the hydrangeas.  For the health of the boxwood, I did not want a lot of foliage shading them.  For hydrangeas blooming from top to bottom, the boxwood would have needed to be planted much further away.  I did not have the luxury of that kind of space. This is what I mean by pruning with a purpose.  Good pruning encourages the plant to grow in a way and direction that works with the natural habit of the plant-and the intended design.
limelight hedge 2
This limelight hedge was planted with the specific intent of providing dense screening from top to bottom.  The branches at the bottom are slightly longer and wider than the branches at the top.  Hydrangeas, like most other deciduous shrub, cannot be pruned with a hedge trimmer.  Cutting every branch at exactly the same height produces a proliferation of growth all at the same level.  A single cut may produce 3 or 4 breaks, or new buds.  This denies light and air to the branches below.  Deciduous shrubs pruned for years in this in this manner have a thin green outer layer, and a dead twiggy interior.

pruned-limelight-hydrangeas.jpgThink shag hair cut.  Shorter on the top, longer on the sides, with each cut an alternate length and direction. Each branch has to be pruned individually, one at a time-each at its own level.  Every branch needs a home of its own, uncrowded by the leaves of a neighboring branch.  Clusters of leaves that pester one another and compete for light eventually leads to overall decline.  Lots of deciduous shrubs grow large.  A big shrub planted in a tight space that always needs downsizing will never look or be happy and healthy.  If you don’t have room for a limelight hydrangea, which will mature at 6-8 feet tall, plant Little Limes.  They can comfortably be kept at 4 t0 5 feet tall and wide.

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There are a few plants that are tolerant of shearing. Boxwood and yews are tolerant. Lindens have been pleached and formally grown into overhead hedges for centuries.  A hydrangea is not a member of this group.  They have a loose and shaggy natural shape.  Pruning them needs to work with this natural  habit.  Landscapes where every deciduous shrub is pruned into ball, mushroom or cube shapes is a look that is heavy handed, and not good for the plants. Proper pruning takes a lot of time, but that time is well spent.

pruned-limelights.jpgThe effect of just one year not pruning my limelight hydrangeas is obvious.  The shrubs have developed long bare legs  Pruned down to 36″ tall will encourage lateral buds to break, and some branching at the bottom.  From a distance, the boxwood disguises this legginess. In fact, I prune my hydrangeas differently every year.  I like trying out different approaches and observing the results.  Shrubs are quite tolerant of gardeners.

hydrangea-branching.jpgIf you do have a shrub that is had become overgrown, or is suffering from long standing poor pruning, it is possible to renovate.  An overgrown lilac might benefit from having a couple of old thick branches cut to the ground.  This will encourage growth from the base.  A privet that has been cut into a ball shape for too many years might be a good candidate for the swiss cheese treatment.  Cut holes in the exterior thicket of branches so light can penetrate.  The light is coming from overhead, so treating the top surface of the shrub is the most effective way.

hydrangea-budding.jpgI would say my hydrangeas have been cut hard this year.  I see I have buds breaking here well below the cut.  The trick is to cut close enough to a bud so no time and energy is wasted on a stub that will eventually die back.  Cut too close to a bud, and you may damage it.  For this reason, I may prune my hydrangeas again in a month of so.  To encourage more branching.  Very hard pruning can result in just a few stems, with overly large flowers that droop over.  A sturdily branched hydrangea properly pruned will be a joy come bloom time.

 

 

Spring Pruning

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The day you put a plant in the ground is the first day of a relationship.  If you plant cosmos, that relationship constitutes one season.  If you plant a tree, that relationship might survive for generations.  If you plant shrubs, you could have a good many years of pleasure ahead of you-provided you prune.  Woody shrubs, left to their own devices, go to rack and ruin.   They spend no end of effort piling on enough wood to send the tips of their branches to the sky.  What is the big attraction of the sky?  No competition for light, air, and rain. No shrub feels any inclination to bloom where you want to see blooms-at eye level, that is.  Plants grow with survival in mind.  Should you have another idea in mind, wade in.  Participate.

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Shrubs will grow sideways, around an obstacle.  They will sprout back, if cut to the ground.  They will survive the indignity of a homeowner with a hedge trimmer gone amok.  They will survive, even though the overall shape may be ungainly, or sheared to within an inch of its life.  The instinct to live is strong.  Lucky for me, and every other gardener who has learned on the job.  Pruning a hydrangea is not hard-it just requires the patience to consider every branch, before you cut.  I prune each branch, one at a time.

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A well pruned hydrangea looks like it has had a shag haircut. Every branch has its our airspace. This means some branches get last year’s flowers cut off-only. Other branches get 8″ removed. Others get 16″ removed. Some old and thick branches in the middle get cut even harder, so air and light can reach down in to as many branches as possible.  Some gardeners prune their Limelight hydrangeas to within 14″ to 24″ of the ground, forcing them to produce basal shoots which originate underground. This method tends to produce a shorter shrub, with fewer and larger flowers.  I dislike cutting this hard-it takes so long for the shrub to regain a natural and airy shape.  I would rather have lots of flowers, than a few gigantic flowers.  I would rather plant the shorter growing version of Limelight- “Little Lime” – than prune a Limelight too hard.

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I like my Limelight hydrangeas tall, and I like lots of flowers. My yews are 48″ tall at this end of the garden, and the arborvitae are 14′ tall.  The hydrangeas grown 6′ to 8′ tall-perfect for this spot. For good flowering from top to bottom, the lower branches need to be left long, and the top branches need to be shorter. The finished shape should be very loosely pyramidal, or like an egg on its side.  Step back frequently, to see how things are shaping up.  This hydrangea blooms on new wood, so no matter how you prune, you will get flowers.  Shearing a branch will encourage that branch to produce multiple shoots below the cut.  Thicken up, and out.  As long as the exterior shape is loosely described, the shrub will prosper.  Shearing deciduous flowering shrubs may take less time, but produces less than desirable results.  Renovating shrubs that have been sheared takes a long time.  One cut at a time-this is my advice.  Invest in a great pair of pruners-this makes the work easier.  The moment that all I can hear is the birds, and the action of the pruner blades bypassing each other, is a spring gardening moment I treasure.

pruning-roses.jpgI do grow a few shrub roses.  Sally Holmes, Carefree Beauty and Earthsong.  I have read lots of articles about pruning roses, none of which I have paid much mind to.  I stop dead heading my roses in mid-August.  I actually love the rose hips in the fall and winter.  In the spring, when the buds swell, I prune. The swelling of the buds?  You will recognize swelling buds when you see them.  My roses bloom on the new shoots.  I never cut a branch back by more than 1/3rd.  I prune the entire collection of roses as if they were a single plant.  I leave them loose. Last fall I secured the summer’s growth of the climbing roses to the wall-not much needs to be done to them now.

rose-hips.jpgOccasionally I will hard prune an old climbing rose cane low to the ground.  This keeps new growth coming from the bottom. Pruning stimulates growth.  Pruning a climbing rose cane 6 feet off the ground will result in a rash of shoots.  A long stalk with a tuft of shoots on the top-not the best look. Any cane which you can train to grow horizontally will flower more heavily.  If you think about the where the sun and rain comes from, this makes sense.  Is the afore mentioned a guide to pruning roses-not really.  Every gardener has to deal with their roses one to one.  Look at them, and decide how to prune. I prune my roses so they have the best possible overall shape.  Most roses are very ungainly growers, so pruning for a good shape is not always so easy.  That’s why I grow asparagus with my roses.  The  ferny fronds conceal those awkward and ungainly branches.  Do I prune my asparagus over the summer-oh yes.  I keep them at a height which conceals those legs.  Does this affect my asparagus crop?  Maybe.  But everything in the garden is about choices.  I want great roses more than I want home grown asparagus.

beech-ferns.jpgI do not cut back my beech ferns in the fall.  The dead fronds mulch and protect the European ginger over the winter.  By April 1st, those fronds have cut loose from the crown.  I do not need to prune.  I rake them off.  A rubber rake does a great job.  My fingers do the best job.

european-ginger.jpgThe European ginger has already been busy, sending out new shoots.  A steel rake, or a size 8 boot can damage these tender new shoots.  One of the pleasures of the spring-the new growth.  Friable soil.  My housekeeping inside-rather rude and abrupt.  I just want to get the job done.  When I am cleaning the garden in the spring, I take my time.  I do it-gently.  I have a relationship with this garden that I intend to nurture.

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Lifting a lower branch of a spruce, I see icy snow. The transition from winter to spring has been incredibly slow this year. Really shady spots in my garden are still frozen. The night temperatures are still below freezing.  Frozen ground, frozen branches-my advice is to let them be.

April 2 2013 (40)The hellebores are awake.  Last years foliage has collapsed in a heap on the ground.  Every day I think about cutting that old foliage away.  Clean and bare is not always the best situation.  The newly emerging flowers benefit from all that fluff. The transition from winter to spring can be a rocky journey.   Sometimes, the best thing to do is to do nothing.

hellebore-flowers.jpgLast year’s foliage protects those flowering stalks, ready to emerge.  A warm spell in March proved to be damaging.  The buds sensed it was time to grow.  Nature had a different idea in mind.  We have had a run of really cold weather, the past 3 weeks.  Some of the exposed buds on this plant are black with the rot produced by freezing temperatures.

uncovered-hellebore.jpgCutting away last years foliage  exposes new flower buds.  Very tender flower buds.  Just to look at them, you would know they are not armed against the cold.  I cut the dead leaves away, and put them back over the top of these buds.  It is too soon to clean here.  What constitutes better days?  Warmer nights.  The ground is still very cold.  It will be 2 months before the soil really warms up in my zone. Hellebores do not require warm soil, but the flowers will be damaged by night air temperatures in the mid to low 20’s.  They need all that litter on the ground over them.  It’s not time yet to wash and put away the blanket.

hellebore-seedlings.jpgI am shocked and pleased to see that I have hellebore seedlings sprouting.  I spent a few moments taking this in, before I covered them up.  I am not sure how long it will be, before I expose them to the light of the new season.  The pruning and the cleaning-all in good time.  A slow spring-this is what we have now.

Time For The Limelights

limelight hydrangeas

Summer blooming hydrangeas appeal to almost every gardener.  Each flower head is substantial.  Comprised of hundreds of tiny florets, a single cut stem is a bouquet that celebrates the beauty of the summer season. One shrub in full bloom delights the eye.  There are no end of cultivars-some white, some pink, some blue on occasion. They are broadly tolerant of a variety of conditions, but appreciate their fair share of sun, space, and water.  I plant Limelight hydrangeas, and the new dwarf version, Little Lime, more than any other variety. They are vigorous growers, and bloom reliably.  

summer flowering hydrangeas

My zone is a little too chilly and unfriendly for a good many hydrangeas.  This is just me talking, but I only have one westside client who has been successful in growing blue hydrangeas.  Her success is a mystery to me.  The pink flowering varieties, available in my zone are easy to grow, but so reluctant to bloom.  Sporadic bloom on a sizeable shrub makes me look like I don’t know how to garden.  My clients on the east side of the metropolitan area have no problem cultivating pink and blue hydrangeas. I can’t help but think Lake St. Clair mitigates seasonal extremes. 

hydrangea hedges

 I am satisfied to grow the hydrangeas that do well in my area.  This means Annabelle,and Limelight.  White hydrangeas, these.  They are easy to grow, and so willing to bloom.  Come June, the Annabelles delight every gardener with their snowballs.  My favorite place to site them is on a slope, as they are stubbornly floppy in habit.  Come the first of August, the Limelights transform the garden.    white flowering hydrangeas

Their greenish white conical flowers develope over a period of a few weeks.  Chubby, luscious,  and very large, the showy flowers dominate the summer landscape.  I have 25 or 30 of them in the ground at our landscape yard.  They are planted in gravelly soil, and make due with whatever water comes from the sky.  They are a quarter of the size of these plants; the flowers are tufts.  Plant hydrangeas in compost enriched soil that gets regular water.   

great shrubs for the landscape

 Large growing hydrangeas can be stalky-leggy.  Skillful pruning in the early spring can help keep them green and blooming to the ground.  But a good underplanting gives them a very finished look.  I like to face down most large growing shrubs with a smaller growing shrub or perennial.   Boxwood does a great job of concealing those inevitably gawky Limelight legs.  They do a better than great job of giving the hydrangeas some winter interes

hydrangea limelight

 This block of limelights is wedged in between a hedge of yews, and an L of boxwood.  In a different, cooler, and more rainy summer, the tops of those yews would be dark emerald green, rather than the color of toast.  But the lime green second flush of growth on the boxwood is a beautiful textural contrast to the hydrangeas.  No legs on display here.

white hydrangeas

 I prune my hydrangeas as soon as the buds swell in the spring.  I give them a shag haircut, by shortening the long branches on the top. I rarely prune the bottoms.  Heading back the long top branches allows light to reach the bottom. Good foliage and flowers requires good light.  It is so easy to see in this picture that the heaviest bloom is occurring where there is the most exposure to light.   

white blooming hydrangeas

 Limelights can be pruned as low as 24″-30″ in early spring.  Hard pruning produces fewer, but larger flower heads.  I prune my hydrangeas lightly, as I like them tall, and I like lots of flowers. They make a beautiful backdrop for this pot in August.  They hydrate the look of my summer landscape.

My blocks of hydrangeas are sequestered behind a pair of yew hedges-one formally pruned, another left shaggy.  Thuja nigra backs them up, and sets off the white flowers to good advantage.  This is the juciest moment I have had to date in my garden all season-you bet I am enjoying them. 

 

 

 

More On Pruning

This hedge has everything going wrong.  More than likely, it gets topped every year with an electric hedge clipper.  The work goes fast, and the result makes me cringe.  Repeated cuts into the top layer has resulted in so many branch breaks that the resulting dense top layer of foliage forms an impenatrable barrier to light to the interior of the shrub.  This hedge is mostly sticks, all year round.  Pruning branches individually takes a lot more time, but the time it takes is worth it.  Sometimes I describe pruning as a haircut-specifically, a shag haircut.  The branches on top are short and shaggy; the upper side branches are headed back slightly to allow light to get all the way to the bottom.   

The early season look of this hedge is ample evidence that skirting up a shrub is a bad idea.  In an effort to keep the sides of the shrub perfectly vertical, all those stray side branches have been pruned off. Not so clear from this picture is that the hedge had been planted so close to the driveway that any side branches would impinge on that hard surface.  This hedge in its natural state would be 4 times as wide, and beautiful.  A skirted shrub is all legs, with little tufts of green on the top.  Naturally, carefully consider placement before you plant. 

This lilac hedge is wedged between two driveways. There really isn’t room between the drives for any plant that I know of, even though the screen is welcome to both neighboring parties.  To make the best of a bad situation, regularly removing the largest stem to the ground every year will encourage the lilac to sprout from the ground level.  This keeps the green coming from below. This hedge has a decidedly layered look.  A lower layer of green, then a taller layer of sticks, then another layer of green. This striping is very evident in early spring. Its clear these lilaces were pruned across the top, all the same height, on repeated occasions.  Pruning branches irregularly, at all different heights, encourages green all over.  Only a few plants can be pruned into boxes and globes, or balloons.   Balloon bushes are those skirted up stick shrubs with balls of green at the top; they look like a hot air balloon, only not as pretty.  This is a particularly displeasing look, as it bears no remote resemblance to any plant’s real habit of growth.

These hydrangeas have been pruned back to a few main trunks.  Though the look is sparse, there is little to fear.  Limelights bloom on new wood.  They do not bloom until July in my zone.  There is plenty of time for this shrub to grow and put out flowers.  Cutting back to these main trunks in the spring keeps the shrb in scale with the allocated space in a natural way.  Letting pruning go for too long only makes your shrub renovation look even more extreme.

Hydrangeas grow fast.  This bleak look lasts for only a short time in the spring.

I prune my own hydrangeas to a roughly symmetrical height, first.  Mine are grown in blocks, not rows; they make a substantial mass when they bloom.  They are also tucked behind a Hicks yew hedge; I need every inch of height I can get out of my hydrangeas so I can see their flowers from the street.  Pruning should be done with a particular end result in mind.  I do not prune my hydrangeas any lower than 30″ overall, as I like their height.  

Once I have pruned down to the height I like, I then prune out crossing branches.  I may prune out the center of the shrub if I think it has gotten too dense. I leave the outside branches alone. There might be some vague resemblance to an egg laid on its side, with holes in the top-when I am done pruning.  

It is easy to see that this single old calloused cut from last spring resulted in three new branches.  Pruning is not the end of something-it is the start of something bigger.  These three branches from last year, located in the center of the shrub, I have pruned back hard. I like to avoid long runs of woody branches-as I do not like hydrangea plants that droop.  A sturdily branched undercarriage makes for a strong and weather tolerant shrub. 

This bed of hydrangeas belongs to a client.  They face down an old stone wall which is but four feet tall. She cuts them back very hard-to within 14 inches of the ground.  She has in mind to keep the flowers at about the same height as the wall.  Pruning hard keeps the eventual plant height in bounds.  


In bounds, but blooming beautifully; this I like.