Beauty is High Maintenance

Beauty is High Maintenance

One of the most frequent comments I hear from customers is that they want a “low-maintenance” yard.  But they also say they want a nice yard.  In my experience, there are three ways to have a low-maintenance yard:

1) Move to a condo

2) Pave over your entire yard

3) Get used to ugly, also called “natural.”

Folks, natural is the Rocky Mountains, which are beautiful.  “Natural” in a yard is a homeowner convincing himself that his neglect is somehow pretty.  Natural = neglect.  And neglect = invasive weeds, runaway perennials, unruly shrubs, and trees that self-destruct, over time, from poor branch structure.

Unless your yard looks like this, it will need work! R.LePage photo.

Beautiful urban landscapes take time, effort, and money.  Unfortunately, there are a lot of landscapers out there that are selling lies, convincing people that they can install a low-maintenance yard full of beautiful plants.  This just isn’t true.

All that said, there are ways to minimize the amount of required maintenance.  But if you have a yard, you will have to work on it, or hire someone else to do it.  I think the term “low-maintenance” is often heard as “no-maintenance.”  Once again, if this is what you want, move to a condo.

So how does one reduce the amount of maintenance in their yard?  There are a few ways:

1) Plant drought-tolerant species from good nursery stock

More and more, I’m moving toward the native species and those that have proven drought tolerance.  Pine, trembling aspen, dogwood, wild rose, dwarf birch, various willow shrubs, and others, may not be the most showy plants, but thoughtfully planned, you can design a great yard from these trees and shrubs.

Avoid species of trees that are prone to disease, such as mayday, ‘Schubert’ chokecherry (black knot), and mountain ash (fireblight).  Also avoid trees that have annual insect problems, such as birch (leafminers, aphids, bronze birch borer.)

2) Plant trees and shrubs in the right place

Very few, if any, people seem to read the labels on the plants they buy.  If they did, they would be able to determine the mature height and spread of the tree or shrub, thus saving themselves a lot of pruning  later on, trying to make their tree fit their yard.

Properly planted crabapple. S.LePage photo.

Pick the right tree for the right place, and you will have very little future maintenance.  I recently drove through the new Vanier neighbourhood in Red Deer to have a look at what new homeowners were planting in their tiny, postage-stamp yards.  What I saw was a disaster.  Almost every  yard had the wrong tree species planted in the wrong place.  In 5 to 10 years, those trees will have over-grown their spot and will become a problem.  In 20, most trees planted in their current locations will be gone, removed as nuisance trees.  I suspect these new neighbourhoods won’t look like much in 20 years, which is too bad, because gone are the days of the big yards, with all those big shade trees, which make up what we call the urban forest.  Careful planning is a must.

The rosybloom crabapple in the centre of the above picture was planted such that when it is mature, its spread will only reach as far as the fences that surround it.  It will not encroach on the neighbour’s yard, or the parking area behind the fence.  It will need structural pruning each year for a few years, but essentially, it is a low-maintenance tree.

Also, plant your trees and shrubs properly.  Do some reading beforehand to make sure you’re doing it correctly.   A lot of my maintenance work is a result of improperly planted trees.

3) Don’t over-prune & stop “shaping”

Professional high-maintenance pruning in White Rock, BC. S. LePage photo.

There is a disease in the urban landscape that I call ”Old Man Syndrome.”  It’s everywhere and I pray I never get it.  This is where older, retired guys get really bored and continuously, and indescriminately, cut and shape their trees and shrubs, such that everything is short and round.  Ironically, these are the same people that want a low-maintenance yard the most.  No wonder!  They are slaves to what they’ve done!

Trees and shrubs respond to hard pruning by putting on a new flush of growth to replace what has been cut.  In a low-maintenance yard, with good nursery stock planted in the right place, little pruning is needed, except to remove diseased or deadwood every several years.  As soon as trees and shrubs are shaped, they will need to be re-shaped, and re-shaped, and it never ends.  Hard pruning, without understanding the nature of the plant, can also ruin the structure and natural beauty of that particular species.

4) Create mulched areas, or beds, around all your trees and shrubs

Mulch is so important.  It holds in soil moisture and greatly reduces watering requirements, prevents competition between the lawn and the trees, and breaks down slowly to provide nutrients to the plants.  It will also slow down weeds, and make the weeds that do grow through it easier to pull.  Simply, mulched trees are healthier and “low-stress”, and that’s what you want.

Don’t waste your money on expensive landscape fabric.  It doesn’t work, and its a nuisance to deal with if you have to pull out plants later on.  And it’s plastic!  Do you really want to bury a bunch of plastic in your yard?

5)  Perennials and annuals are high-maintenance

If you don’t want to work in your yard, don’t plant a bunch of flowers, or, plant them in pots and place them in your yard.

6) Don’t go after the “perfect” lawn

I’ve seen a lot of yards.  The nicest lawns are meticulously cared for by people who have the time to devote to it.  They need constant water, fertilizer, and weed control.  For low-maintenance types, that’s insane.

Minimize the amount of grass in your yard by expanding the mulched tree and shrub areas.  Trees are far less maintenance than lawn.  If you are putting in a new lawn, I recommend using low-maintenance grass species: fescues as opposed to Kentucky bluegrass.

Taller grass is lower maintenance than short, constantly mowed grass.  Reduce the amount of irrigation and fertilizer.  Last year, in Sylvan Lake, I only watered my lawn once.  By summer, it was just as green as my neighbour who had a fertilizer company come out every 3 weeks.

These are some helpful hints to lower the cost of your yard maintenance.  If you feel overwhelmed and don’t know where to start with your yard, it is best to call a professional arborist or hoticulturist for a consultation.  A couple of hundred spent on an assessment and some advice can save thousands later on.

 (c) 2012 Wild Rose Garden & Tree Service

12 Things You Should Know About Pruning in Red Deer

Crabapple pruning in late April

For advice on how to prune and maintain a particular tree or shrub, please enter the name of the plant in the search bar above.  If no information is available on this site, please feel free to email us with a request.

UPDATE – Oystershell Scale in Calgary – June 2012

We are currently spraying for oystershell scale crawlers in Calgary.  Over the past few days, I have noticed the highest concentration of crawlers (the immature form of the insect) on apple trees.  They are extremely small, about the size of a pin prick and are greyish in colour.  If you look closely you can see them roaming about on the leaves.  This is the ideal time to keep the population in check with contact insecticides, such as permethrin.  Unchecked, oystershell can decimate an apple tree in just a few years.

Restoration of Two Topped Siberian Elms

I live in Red Deer, which is home to a number of unsavory tree “service” companies.  I’m talking about guys who don’t understand tree biology, tree health, or horticulture.  They know how to cut trees with chainsaws and that’s where it ends.  They get their work by perpetuating old wives tales and myths, and by taking advantage of people’s fears, by selling them on the “hazards” of their landscape trees.  After many decades of such abusive business practices, our city is left with hundreds, if not thousands, of mutilated and decaying trees.  Many of these trees are now hazards, inadvertently created by tree-cutters who were unaware of the harmful effects of poor pruning practices.

On the positive side of things, I spend a good portion of my year restoring “topped” landscape trees for my clients.  Some are very rotten and are best removed and replaced, but many are salvageable over a period of several years, providing that they are still growing vigorously and are not extensively decayed.

A year ago, I started restoration on two Siberian Elms in the Woodlea neighbourhood.  I have these trees on a two-year pruning cycle, at which time I will selectively thin each “knuckle” (or old topping site), retrain new leading branches, and redirect lateral branches to form the main scaffolding of the tree canopies.

This picture shows the elms before I started the restoration process.  The south tree is the one closest to us in the picture and is the better of the two.  Both trees were severely wounded, the topping cuts exceeding 6″ in diameter.  As a result, decay has entered the trunks.

My hope is that the root systems are healthy, and that the new vigorous growth is able to outgrow the rot that is developing in the trunks. The trees were topped 4-5 years ago and the resulting growth had not been touched.  The branches were messy, tangled, lacked structure, and many of them had to be removed.

I was as pleased with the result as I could be, considering what I had to work with.  With all the dead and diseased wood removed, as well as all the redundant growth, the trees took on a much cleaner and more structured look.  One of my goals was to restore some dignity to the trees.

Elms in the summer following initial restoration pruning

While the process involves patience, and some financial input, it is possible to improve the health and look of previously mutilated trees in the landscape, and enjoy the benefits they produce (shade, privacy, dust and noise barriers), without having to wait the many years that it would take to grow new trees. That said, topping has reduced the life expectancy of the trees, and eventually, a new planting plan will have to be considered to replace the elms.

(c) 2012 Wild Rose Garden & Tree Service, Red Deer, AB

10 BEST & WORST shrubs for Central Alberta

A rose in July in Calgary

One of the first books I bought and read when I became a Prairie arborist was Lois Hole’s Favourite Trees & Shrubs.  I still use it from time to time.  It became the bible for woody plant selection and information in the early days of my career, before I had many seasons of experience and observations with hardy trees and shrubs.  I’ve learned a lot since then, and my ideas have changed.  In fact, they continue to change each year.

Simply, many shrubs that are commonly planted here in Alberta don’t really work.  Sure, technically they are hardy, but what does that really mean?  It means they’ll “survive” our winters.  But do we want our shrubs to merely survive, or do we want them to thrive?  The past two long, cold winters have changed the way I think about some of the toughest shrubs, leaving a few champions, and a lot of losers.

Many garden centres, especially the seasonal ones that are set up at grocery stores and wholesale outlets, carry a host of plants that will not survive in Central Alberta, which  is Zone 2b to 3a.  They commonly carry zone 4 and 5 (ie. Okanagan), and sometimes you’ll even see zone 7 plants (ie. Vancouver Island.)  Unless you have an indoor solarium, forget it.  These won’t make it.

Here are 10 hardy shrubs to AVOID planting and why

1) Boxwood – very finicky and slow growing.  Needs a protected site, and even then, it is unreliable.  If you’re moving to Victoria, great, plant boxwood.  If you’re staying here, don’t bother.

2) Forsythia – These plants seem to make it through the winter very well, but the flower displays in the Spring are often forgettable and disappointing, unless the plant experiences a lot of sun and heat on a south facing wall.  Otherwise, the flowers tend to emerge near the lower part of the shrub only.  Recently, I have thought that Forsythia would make an interesting hedge, if kept short, but otherwise, it’s a no-go for me.

3) Ninebark – I used to think Ninebarks were bomb-proof.  After the winter of 2009 and 2010, I now know they’re not.  In fact, I would no longer consider planting one in my own yard.  They suffer horrendous die-back under extreme conditions.  They do seem to come back well if renovated to within a few inches of the ground in late winter.  Also, avoid some of the newer culitivars, especially ‘Coppertina.’  It is prone to powdery mildew.  I planted two in my yard and they died within a few weeks, caked in mildew.  One of the most interesting hedges that I’ve seen was a golden ninebark hedge in Calgary.  After last winter, it is one of the sorriest looking things I’ve seen in an ornamental landscape.  After many years of of maintenance and waiting for that perfect hedge, it now needs to be cut back to grade!

‘Diabolo’ Ninebark in Calgary

4) Potentilla – I also used to think potentillas were among the best shrubs for hardiness.  Not anymore.  This is the number one shrub that I’ve been removing over the past two seasons.  Most look rough at best, shabby at worst, especially those plants in non-irrigated commercial areas.  I have three in my yard that are very young and of excellent plant stock, grown from seed at Bow Point Nursery in Calgary.  But I’m not re-sold yet.  Those three shrubs are definitely on probation in my yard.  I have found that they don’t renovate well, either, getting floppy and misshapen as they grow back.  I’m currently experimenting with new pruning techniques for this species.

Potentilla at its best

6) Purple-leaf Sandcherry – Forget it.  These are garbage and have no place in Alberta.  My Dad grows excellent specimens on his property in Vernon, but they are a disaster in Alberta.  For every nice specimen, I see 10 that are near death.  These shrubs die-back every year and once the deadwood is removed, it is difficult to rebalance what is left of the shrub.  They persist, but they do not thrive.  Please avoid.  In the meantime, I am experimenting with new pruning techniques that I think may be of assistance for this plant.

7) European Cranberry (V. opulus) – Those cute little round cranberry bushes are messy-looking things in winter, sensitve to shaping, and prone to powdery mildew in mid-summer.  One of my least favourite shrubs.

8) Spiraea – I have no landscape use for these plants.  They grow great on the Coast, but here, expect annual dieback and unsightly plants.  Many of the specimens that I’ve encountered this year need to be removed and replaced.  High maintenance and barely hardy.  Try something else.  Once again, there are definitely exceptions, and many people will tell me that I’m full of it.  Anyway, I warned you.

9) Weigela – I have yet to see a really nice specimen.  Too bad, because the flowers are really beautiful.

10) False Spirea – You might just as well plant Canada thistle and quack grass in your yard.  Terrible, invasive, unattractive plants.  If you decide you need these in your yard, make sure they are well contained and that their roots won’t spread.  They are tough to get rid of once they’re established.  They burn well when dry and that is my favourite use for them.  This is the plant you give your in-laws for their gardens!

And now, the CHAMPIONS of the shrub bed

1) Dwarf Korean Lilac (Syringa meyeri ‘Palibin’) -  My favourite pick for 2011.  I love this plant.  The flowers have an intoxicating fragrance and the leaves make this plant my favourite for topiary and formal hedging.  Also makes a great specimen planting.  Beware, they can get much bigger than they’ll tell you at the garden centre.

2) Common Lilac & French Hybrids (Syringa vulgaris) -  The good ‘ol standby.  Bomb-proof.  Nice flowers.  No frills.  And lilac produces what is arguably the most impressive-looking, formally sheared hedge.

Lilac hedge in Ponoka

3) Nanking Cherry (Prunus tomentosa) -  After a long, drab winter, the early blooming pink blossoms of the Nanking are a welcome relief.  These shrubs are not low maintenance, but properly groomed specimens are an excellent addition to the garden or shrub bed.  I love picking the berries when I’m pruning on a hot summer day.

4) American Highbush Cranberry – Get the species, Viburnum americanum.  Some of the cultivars are prone to aphids.  The species is better.  Cranberry has beautiful foliage, nice form, excellent flower and berry display, and fantastic fall colour.  It’s a four season plant and one of my favourites.  I’m also one of the few people that likes the smell of cranberry in the fall.  It reminds me of growing up in the woods when I was a kid.

5) Currants (red, pink, alpine, golden, gooseberry – Ribes spp.) - These are not showy plants, by any means, but they are very tough and produce nice fruit.  Their interesting foliage has a place in a mixed-texture garden, and they lend themselves to intensive pruning and interesting forms.  If you are growing gooseberries or currants for their fruit, beware the currant fruit fly, and make sure you apply an insecticide at the right time, normally when the flowers begin to wilt.  If you miss the timing, every single fruit will have a little hole, with a nice little fly larva.  My favourite plant in my garden is a red currant.

Red Currant in Sylvan Lake

6) Sour Cherry -  Definitely among my favourite shrubs.  Awesome spring flowers and beautiful fruit.  Very little die-back in winter.  A versatile shrub.

7) Red Osier Dogwood – The species, Cornus sericea is best.  I avoid the variegated variety and some of the other cultivars, which tend to get a lot of tip die-back and aphid problems.  Red osier dogwood is native and it’s everywhere.  Very, very tough.  They are easy to maintain and have beautiful stems, great leaves and flowers, interesting berries, and excellent fall colour.  An great choice for any prairie yard, they will also tolerate shady spots and still look good.

8) Mugo Pine (Pinus mugo) - A reliable standby. Most specimens I encounter, while neglected, are healthy. Planted in good soil with occasional maintenance, these plants are bomb-proof, versatile, and lend themselves to very creative pruning styles.

9) Dwarf Birch (Betula glandulosa) – This is a great looking shrub and very, very tough.  It has interesting-looking catkins and nice waxy, roundish leaves.  It is slow-growing, low-maintenance, and makes an nice informal hedge.  My only qualm with this, and every birch, is that it is very susceptible to a number of birch leaf-miner insects, which can devastate the foliage.  If you plant this shrub, you will most likely have to use a systemic pesticide to control the insects.

10) Powderface Willow (Salix commutata ‘Powderface’) – Available at Bow Point Nursery in Calgary, this is fast becoming one of my favourite shrubs.  It has incredible blue-grey foliage that really stands out in the shrub bed.  It is extremely tolerant of dry, hot places, and it thrives in the worst possible growing location in my yard.  It needs sun, however, so don’t put this plant in the shade.

(c) 2012 Wild Rose Garden & Tree Service, Red Deer, Alberta

I Can’t Grow Grass Under My Spruce Tree!

No kidding!  You know, this is one of the top 5 comments I hear all year, from various would-be clients.  It seems that most people have at least one big spruce tree in their yard, and more often than not, people try to do the impossible.  They attempt to grow beautiful Kentucky bluegrass under the canopy of the spruce tree.  Please stop it.  It’s an act of insanity and futility.  That cute little tree the kids brought home in grade 2 is now 30-40′ tall, they kids are gone, and it’s time for a change.  And no, it isn’t the acidity that is killing the grass.  It’s the dense shade and the drought (ie. the tree is out-competing the grass for water, nutrients, and light.)

Typical 20+ year old blue spruce with declining grass beneath. R.LePage photo.

Nevertheless, the crafty do-it-yourselfer tries a number of different strategies to grow that ever-important, flawless lawn.  They raise up the canopy of the spruce tree.  They fertilize, water, rake up countless bags of spruce cones and needles, pray, or whatever.  Most of the time, these things don’t work, and you’re left with either a mutilated tree, or patchy, weak turfgrass, or both.

My recommendation is always the same.  First I try to help people understand why the grass isn’t growing properly and why it isn’t likely to.  Next I offer the solution:  the mulched tree well, an attractive accent to the landscape that not only helps both the trees and the lawn, but showcases the spruce tree and adds interest to the yard.

So we start by gently stripping out  the old, declining sod, from the tree trunk out toward the dripline (the outer edge of the tree canopy.)  Spruce roots are shallow, so we take care to do as little damage to the tree as possible, knowing that it will recover and benefit from our efforts in the long-term.  I used a sod stripper to assist with this job where it was practical to do so.  Removing old sod is grunt work, and the machinery eases the burden somewhat.  At this point, we’re left with a bare tree well.  We chose a peanut-shaped well that started at the house, linking up an existing shrub bed, and returning to the house near the downspout of the eavestrough.

Sod removed and a clean edge cut. R. LePage photo.

So now, all that was left to do was to select and apply a suitable mulch.  This is largely a decision of the homeowner, the possibilities range from natural wood chip mulch, various bark mulches, and a myriad of stones, pebbles, or lava rocks.  Personally, I prefer a medium grind (1″ chip) natural wood chip mulch.  Why?  Because it looks beautiful, retains a nice colour as it ages, and breaks down over time, which feeds the tree and improves the soil condition.  It is low maintenance and only requires “topping up” every few years.

I avoid rock mulches because, as a maintenance professional, I know that these mulches are high maintenance, and you’ll spend countless hours trying to keep them clean and free of falling debris from the spruce tree.  Don’t waste your time.

Now, a lot of people, conditioned by the drone of endless landscape “professionals”, are wondering why I haven’t suggested that you install landscape fabric to control weeds.  Two main reasons.  It doesn’t stop weeds.  And second, because it inhibits the natural process of mulch breakdown, which improves the soil.  You effectively start to create a “soil” on top of a soil.  I promise you, the weeds will come.  You may have to hand pull a few weeds, or you may have to spot spray a couple of times per season with a bit of Roundup or horticultural vinegar.  That’s life in the ornamental landscape.

Apply your wood chip mulch about 2-3 inches deep and avoid mounding it up against the trunk of the tree.  The mulch should not contact the tree trunk.

Finished mulched tree well. R. LePage photo.

One last note about edging.  I prefer a natural edge with no artificial borders (ie. plastic, concrete, bricks, etc.), but a lot of people like formal edging material, and that is fine.  But please keep in mind that the tree will continue to grow and expand the diameter of its canopy.  A natural edge allows you to simply extend the well as the tree grows.  Permanent edging doesn’t, and over time, you might run into a similar problem of your lawn dying back in spots or becoming patchy.

I love grass and the trees, but I give them their space, so they can perform their best in the landscape.  It is also a lot less frustrating to maintain, which means you can spend more time on the deck enjoying your trees, and less time toiling beneath them.

(c) 2011 Shane LePage, Wild Rose Garden & Tree Service, Red Deer, AB, (403) 755-5899

UPDATE – Oystershell Scale in Calgary, June 18/2011

Insecticidal Spray Units - Wild Rose Tree Service

I have been spraying cotoneaster hedges for the past week for oystershell scale. Here are my findings:

1) Oystershell scale has infested Calgary from the core to the suburbs. Every hedge I have encountered so far has been infested to some degree.

2) I see the highest populations of insects on hedges that have never been treated with an insecticide. Some of these hedges look normal right now, but will look half dead by next year at this time. The best way to identify the scale “crawlers” is to hold a piece of black paper, or black leather case under the branches while shaking them. Crawlers are tiny, greyish insects. Most hedges that I have seen are what I would consider moderately to highly infested.

If your hedge is infested, you can use any contact insecticide to knock back the population. Scale crawlers are much like aphids, in that they are soft-bodied, and highly sensitive to insecticides. The window for spraying is short, however, as crawlers soon find a spot to settle down and secrete a waxy coating around them. Once this happens, contact insecticides will no longer kill them. The cooler, rainy weather has likely extended the spray window, but I can tell you that most of my spraying for crawlers is complete, with the last few to be completed on the next sunny day.

Don’t be complacent and don’t procrastinate. Believe me, I’ve seen beautiful 6′ hedges that were “perfect” last year, and that are now half dead, esthetically unappealing, and which now represent a lot of work for the owner, as they will have to cut them back to the ground and attempt to grow a new hedge.

3) Of the 40-50 hedges that I treated last year, I am pleased to say that almost all have no noticeable population of crawlers at this time. Only three of the previously sprayed hedges had any crawlers, and only very few. Also, those three hedges were in neighbourhoods with very high infestation rates, and next to neighbouring hedges that have never been treated.

4) We renovated several hedges last season. That is to say, we cut them down to within a few inches of the ground during winter. We also sprayed the stumps and new growth last week as untreated stumps have scale insects on them and will reinfest the new growth. PLEASE NOTE: Just because you have cut the hedge to the ground does not mean that the problem has gone away. You will still need to monitor the insect population and spray if necessary.

If you have any questions about your hedge, or any other tree or pest related concerns, please call Shane at (403) 755-5899 or email at arborshane@gmail.com.

(c) 2011 Shane LePage, Wild Rose Garden & Tree Service, (403) 755-5899

Cotoneaster – Renovating an Old Hedge

Cutting back the old hedge to 6" above grade

Ready to grow!

A perfectly trimmed cotoneaster hedge can be a great addition to an ornamental landscape in Alberta. Over the years, however, many hedges become overgrown, too big to manage, or infested with insect or disease problems. When this occurs, it may be time for a drastic renovation to ground level.

In recent years, scale insects have ravaged cotoneaster hedges. In Calgary, the pest is oystershell scale; in Edmonton, it is mainly scurfy scale. From my experience, I would say that oystershell scale is more serious, but both insects eventually take their toll on the hedge, by leaving dead, patchy areas in the canopy. Uncontrolled, the insects will kill the hedge. With a regimen of drastic renovation, combined with properly times insecticidal sprays, scale insects can be controlled, and your hedge can cotinue to look great.

Renovation is a dirty, dusty job, but is very straightforward.  Begin at the end of the hedge, and cut all stems to about 6″ above ground level.  Remove dead stems, leaving only fresh, healthy stubs.  New growth will occur from the cut ends, and also from new suckering growth from the exisiting root system.

If your hedge was infested with scale insects, be sure to treat the stumps with a contact insecticide around mid-June, when the immature scale insects are crawling.  New, healthy stems should reach a height of about 2′ the first season.  Hedge training may being as early as the second season after renovation.

For more information on hedge renovation, please call Wild Rose Tree Service at (403) 755-2443.

(c) Shane LePage, Wild Rose Garden & Tree Service, Red Deer, AB

Repairing Winter-Damaged Cedars

Getting started

Finished product

Dogwood (Cornus spp.)

Dogwood is truly one of the most reliable garden shrubs for Alberta.  Native to parkland forest understories, it is also one of the only plants that will grow well in shady areas of the yard.  I consider dogwoods a four season ornamental, with interesting flowers in the spring, nice berries in the summer, great fall colour, and beautiful bright stems to provide winter interest.

There are many cultivars of dogwood available at nurseries.  Personally, I prefer the species, Cornus stolonifera, as it is most hardy.  That being said, all of those rated zone 3 or less should work fine, provided they are planted and maintained properly.

Red-Osier Dogwood (Cornus stolonifera)

Red-Osier Dogwood near Sylvan Lake, AB. Shane LePage photo.

Lately, I’ve taken an interest in Niwaki, the japanese art of pruning, and am experimenting with some mature dogwood plants in Red Deer.  Given enough space, dogwoods need little pruning.  But if it’s a dramatic display of bright new stems, or if the shrubs are included in a dense, mixed planting, where spacing is not desired, pruning is a definite must.  Also, old, overgrown dogwoods tend to benefit from reinvigoration, every few years.

Pruning to Encourage Decorative Stems

This technique is most suitable once the specimen has an established root system.  I don’t recommend the following technique on newly planted shrubs.  In late winter to early spring, cut back all dogwood stems to about 4″ above ground level to form a tidy “stool.”  Don’t be alarmed if the plant doesn’t respond with new growth early in the growing season.  In the Red Deer area, I find that it takes well into July to get a nice looking, regenerated shrub.  It is worth the wait.  The new foliage seems to glow with vigour and rich, healthy colour.  This process can be done annually, but I find that it’s a nice idea to rotate this type of hard pruning between various dogwoods in the garden, alternating years, or perhaps pruning this way every three years, or until they start to encroach on neighbouring plants.  All dogwood cultivars can be pruned similarly.  Yellow-twig dogwood is particularly suited to this technique.

Reinvigoration of Overgrown Specimens

Most often, I am called in to look at messy, overgrown specimens dominating some corner of a back yard.  I prefer to prune dogwood in the dormant season, late fall to early spring, so I can see what I’m working with.  I remove as much deadwood as is necessary for the specimen, but usually dead stems down to 1/8″ diameter or smaller.  The shrub should look neat and clean, for starters.  Next, I remove conflicting stems; those that intertwine, saving those that best contribute to the overall form of the shrub.  I like all remaining stems to have a bit of space, especially if it will be several years before the shrub is pruned again.  Lastly, I reduce the height and width, only as much as necessary, and using reduction-type pruning cuts, in order to balance and contain the shrub.  The end result is a tidy, attractive, balanced, and healthy looking specimen.

Irrigation & Fertilization

As with most woody plants, dogwoods prefer a moist, well-drained soil, with a wood-chip mulch cover.  Planted and maintained in this manner, these plants should not require irrigation or fertilization.  I would consider watering only after prolonged hot, dry weather in summer.

Pests

Dogwood is insect and disease resistant.  I have, however, encountered some problems, namely aphids and oystershell scale.  Aphids are messy and unattractive, buy they aren’t that serious.  Hose them off of try some relatively non-toxic spray, such as an insecticidal soap.  Other contact insecticides work well, such as Malathion, but please use caution when using chemicals.  Oystershell scale is more serious, and must be controlled when the scale “crawlers” are active, in early to mid-June.  Use any contact insecticide.  In my practice, I have used Orthene with excellent success and it offers systemic control as well.  Timing is everything.

(c) Shane LePage, Wild Rose Garden & Tree Service, Red Deer, AB, (403) 755-5899

Oystershell Scale

Of all the pests that I work with in Calgary and Red Deer, the scale insects are doing the most damage.  And while European Elm Scale is now familiar to homeowners and tree professionals, oystershell scale is largely unknown to people, and its potential for damage grossly underestimated by arborists and landscapers.  It attacks 120 species of ornamental trees and shrubs, many of which are commonly planted on the Prairies.  Without proper recognition, this pest will destroy countless plant materials in Alberta.

Oystershell scale on cotoneaster twig. Biterroot Restoration photo.

 A fellow arborist first called my attention to oystershell scale in Calgary in 2006.  He had a number of clients in the Inglewood neighbourhood, with dying cotoneaster hedges.  We didn’t know what it was at that time.  I looked at the hedges, took a sample, and soon identified it.  Since then, oystershell has spread throughout the city, particularly severe in some neighbourhoods, such as Riverview and Douglasdale, and just getting started in others, such as Acadia, Lake Bonavista, and Britannia.  Cotoneaster is the preferred host, but we have now seen it infesting common lilac, crabapples, edible apples, hawthorn, and green ash trees.  Entire streets have lost their cotoneaster hedges in at least one southeast neighbourhood.

Identification

Infested cotoneaster hedges die-back in patches, leaving large voids in the hedge.  Close inspection of the twigs reveals thousands of adult oyster-shaped insects encrusting the stems.  In early to mid June, if an infestation is not obvious, take a piece of black paper or similar sized piece of black leather (I use a leather folder), and shake the branches over it.  Look closely.  If scale is present, you will see many tiny orange or reddish “crawlers”, which is the immature stage of the insect.  A few crawlers might not warrant control measures.  A heavy infestation will require a spray.

Pest Control

Oystershell scale insects are easy to control.  They appear to have one generation per season in Calgary.  The crawler form is active in early to mid June, depending on weather conditions.  Inspect the leaves as described above.  If the infestation level is moderate to high, you can spray the entire canopy, thoroughly, with any contact insecticide.  I recommend hiring a licensed pesticide applicator, as they have an arsenal of different chemicals, as well as appropriate spray and safety equipment.  I have successfully used permethrin, malathion, and acephate to control these pests.  I prefer acephate as it gives systemic control for up to several weeks, should my timing be off slightly.  Dormant oils in late winter, before bud break, may offer control as well, although I haven’t used this method .  Spray all other infested trees in the same manner.

Renovation of Infested Hedges 

Heavily infested, or patchy hedges, are unsightly and will never recover as well as homeowners would like.  In this case, the best thing to do is 1) cut the hedge back to about 8″ above grade in late winter, before bud-break.  You may get away with cutting back sections of the hedge only; 2) in June, spray the sprouting stumps with a contact insecticide (oystershell will attack stems right to the base of the plant); and 3) as your new hedge grows, monitor pest populations in early June and spray with a contact insecticide, if necessary.  Through careful monitoring and appropriate spray treatments, this insect is easily controlled.  Exception:  If you hedge is “nearly-dead” or devoid of vigour, you would best remove, grind the stumps, and replace the plants.

For further information, please call Shane at Wild Rose Tree Service at (403) 770-2974.

(c) 2011, Wild Rose Tree Service & Pest Control, Red Deer, AB