trees

Training Shrubs to Single-Stem Tree Form

Training Shrubs to Single-Stem Tree Form

Looking to add a distinctive feature to your yard? Try training shrubs into a long, branchless central stem topped with a full head of foliage. With quality plants, the right technique and patience, you can transform your favourite shrubs into dynamic tree silhouettes. Here’s how.

  • Start with a high-quality shrub in a one or two gallon pot and plant as you would any shrub.

  • Examine the shrub and select the largest, healthiest stem. This will become the ‘trunk’ of your tree-form shrub. Prune off most of the other stems, leaving some extra branches untouched for the moment. The extra foliage of these branches will give the plant the energy it needs to grow.

  • Maintain the tree form by pruning off new side shoots so that all of the plant’s energy goes into the remaining stem.

  • Stake and rod the stem to keep it upright. The rod and stakes should remain in place until the selected stem is able to support the weight of the plant.

  • Once the shrub reaches the desired height (1.2 m of clear stem is a good guideline), clip the top to force buds out, and remove any buds on the stem. This is also the time to remove those extra branches you left on the stem for plant growth. Treat like a normal shrub to produce a nice round head.

  • The shrub will continue to produce shoots in unwanted areas. Remove these shoots to maintain the tree form.

Make sure your expectations are realistic—training will not transform a 2-m tall shrub
into a 4-m tall tree, though your shrub may grow a little taller than usual because the
plant’s energy has been redirected to a single, central stem.

You can train almost any shrub, but here are a few suggestions to get you started.

Amur maple
Russian olive
Lilac
Evans cherry
Ninebark
Potentilla
Dogwood
Hardy roses
Hydrangea
 

Multi-Stemmed Tree Forms

Many large shrubs can be trained to multi-stemmed tree forms of three, five or seven
stems. Russian olive and amur maple look beautiful when trained to these forms.

Buying Tree-Form Shrubs

If you like the look but don’t feel like doing the work, you can buy mature shrubs in tree
form. Some of these shrubs are trained to tree form (dogwood, potentilla, ninebark, hydrangea), while others are created by grafting a shrub such as lilac or caragana to a
compatible rootstock. Note, however, that grafted tree-form shrubs are generally easier
to maintain than trained tree-form shrubs, as the rootstocks are chosen both for height
and their tendency to avoid creating side shoots. Grafted tree form shrubs come in a
variety of heights. In some cases, the central stem may be a metre tall, in others only
half that. It all depends on what the grower has chosen.

Garden Alert: Poplar & Aspen Borers

One pest that is causing a lot of grief for those who have poplar trees on their properties is an insect called the Poplar Borer.

It is a native beetle that evolved feeding primarily on native aspens, but has developed a taste for Swedish Columnar aspens that are typically planted in rows along fences for privacy screening. Poplar Borers are rather large, gray beetles with faint, yellow stripes on its body and antennae that are as long as its body.

The problem with these borers is that they not only feed on the green “phloem” that sits just below the bark and moves sugars up and down the tree, but the larva (worms) also tunnel into the wood and leave a labyrinth of trails that weaken the tree, leaving portions of the trunk prone to snapping-off on windy days.

Aspen Borers prefer aspens that have trunks about 10 cm wide or larger and they typically seek trees that are stressed. The adults prefer to lay eggs on the south to southwest side of trees that have lots of exposed bark (extra trunk heat is better for larva growth and development).

The lifecycle of Aspen Borers can take several years to complete in our region, but once they invade trees they are very difficult to control. Given the great benefits of having Swedish Columnar aspens, and the expense of removing these trees, the battle to keep the borers at bay is critical.

Here are some of my observations and a bit of a game plan for Poplar Borer:

  • Aspens growing in landscape fabric with rock around the base are the worst affected, typically
  • Drought stressed aspens growing in poor soil are also preferred by the borers
  • Aspens with branches removed on the south/southwest side of tree are attacked more often

Symptoms of borer attack:

  • Small holes in trunk with brown sap stains on bark
  • Small piles of ‘wood shavings’ at trunk base from borer tunneling

What can be done?

  • Inspect your poplars several times during the growing season and look for any signs of damage
  • Pest control products like ‘Garden Protector’ can be used as a trunk and foliage spray prior to the borers penetrating the wood
  • If the borers enter the wood, control is difficult. A number of gardeners have been quite successful applying Knock Down aerosol insecticidal spray directly into the entry holes on the tree trunks.

Aspen Borers are destructive pests so if you have Swedish Columnar aspens always be vigilant! Being proactive with controlling the beetles is the best strategy!

- Jim

What Lies Below

Over the years, I’ve received thousands of leaf, stem, and soil samples from gardeners who need help figuring out why their plants aren’t growing the way they should, and how to get them back on track.

Often, the diagnostics are pretty straight-forward and simple. If the problem is a large insect - like a cabbageworm - identification is pretty easy and there are a number of good products available for control. 

But many plant problems are more complex than voracious cabbageworms, and a lot of background information is critical when performing the "Plant Forensics”. Good samples of plant parts, lots of good photographs, soil samples, and historical data are really valuable tools for solving the really difficult plant problems. 

Since trees are some of most high-priced and expensive garden plants, they comprise the majority of the plant samples that I receive and they are often the toughest problems to solve. 

The one tip that I will offer those who have tree problems is to spend as much time looking "down" as you do looking "up". Trees are analogous to icebergs in a way. Just as about 90% of an iceberg’s mass is below the sea surface, 90% of the serious problems that I see with trees originate below the soil surface.

And neither ships nor trees fare well when due consideration is not given to what lies below.

~Jim Hole

Mr. Appleseed

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My Dad was a bit of a "Johnny Appleseed". He loved nothing better than planting trees (not just apples) and planted thousands of them over his lifetime.

Before he moved to the farm, back in the '50s, the land he purchased was pretty much stripped clean of trees to make way for crops like alfalfa and barley. But Dad knew that trees were invaluable for trapping snow during the winter and providing shelter for heat loving vegetable crops. He also knew that trees reduced soil erosion and provided habitat for wildlife. 

Today, while most of that farmland has been converted to houses, some of Dad’s shelterbelt trees remain, providing shade and beauty for residents and visitors alike.

People would often ask Dad about which tree was his favourite and he would just say, “All of them”.

 And all of them was a heck of a lot of trees.

~Jim Hole

You Plant A Tree For Your Grandchildren

About 10 years ago, my neighbour’s spruce toppled in a windstorm and smashed into our fence. The middle section of the fence was obliterated, but at least our house was spared.

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These past couple of weeks I have visited a number of homes that have trees with structural problems. One was an apple that had a large branch snap during a snowstorm. A couple of weeks ago, an acreage owner had a poplar topple during a windstorm resulting in a severely damaged roof. Finally, a young couple with small children, were asking me about what should be could be done about their neighbour’s large poplar tree that was leaning, precariously towards their house.   

As a certified arborist, I’ve seen a lot of trees with a lot of problems. While many people tend to focus on insect and disease problems on the tree’s foliage, the major of a tree’s problems (about 80%) originate in the root zone. Preventing a tree from becoming ‘hazardous’ is not difficult if the proper steps are taken beginning with something as ‘simple’ as transplanting. Incorrect planting depth, poor soil, improper staking, and inadequate or excessive watering are mistakes that are often made during transplanting that have a huge impact on trees years later.

As the saying goes, ‘You plant a tree for your grandchildren’. It’s important that they have the opportunity to enjoy it…safely!

~Jim Hole

 

Iseli Trees

Our Terraces are now stocked with dozens of different varieties of beautiful and rare conifers and evergreens, spanning in size from giant forest trees to tiny miniatures.

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Conifers provide an exciting array of colour from the darkest greens through the brightest yellows, blues and even red tones. 

The flowering parts of many conifers can add seasonal interest with their colours ranging from bright scarlet reds, pinks and purples to soft shades of green, yellow and orange.

Here are a few of the unique varieties we have this year:

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"Uncle Fogy" Pinus Banksiana  - Wildly undulating, pendulous branches give unique character to every plant of this distinctive form of Jack Pine.

The plants bend and swoop to create a curvy, living sculpture decorated with resinous winter buds.

This collector's plant, first discovered in a garden in Richfield, Minnesota, seems to be a reference to everyone's eccentric relative. Extremely hardy and adaptable, "Uncle Fogy" tolerates heat, cold, and dry, sandy or poor soils.


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"Horstmann's Silberlocke" Abies koreana  - This Colourful, hardy Korean Fir stands out in the garden with stunning two-toned needles.

The Needles of this small, pyramidal tree are recurved, displaying the silver-white undersides which give a gleaming colour and uncommonly beautiful textural effect.


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"Formanek" Picea Abies  - This radically prostrate, slow-growing form of Norway Spruce will become a densely matted, spreading carpet over time.

If staked up, it's arching, weeping branches cascade down and create a pendulous form. Unstaked, it is the perfect plant to creep over and around rocks and walls.


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"Westerstede" Pinus Cemba - Named for an ancient German city in a nursery region similar to Oregon's Willamette Valley, this beautiful pine represents the finest in hardy garden conifers.

Long luxurious needles give the small upright tree a full, fluffy look. Slower and wider than other cembras, it has graceful branching, attractive colour, and striking cones that offer year-round interest and character in a small space.

 

Come down to Hole's to see all the different varieties we have available this year!

 

When to Prune Your Fruit Trees

Now is a great time to prune those long neglected apple, cherry, apricot, pear, and plum trees. 

I know that a lot of people become stressed-out about pruning fruit trees, fearing that they will irreparably harm them.

While it’s true that bad pruning can harm trees, no pruning is often just as bad if not worse.

Here are a few simple rules for pruning your fruit trees:


•    Don’t remove more than a quarter of the branches in any one year
•    Ensure that every branch is attached to the tree at a wide angle. Narrow "V-shaped" branch attachments are weak and can split
•    Remove broken branches
•    Remove crossing branches
•    Never leave a "stub" but never "flush cut" a branch, always leave a "collar" that is a few millimeters deep 

If you are still a little apprehensive about pruning, pop on down to Hole’s, and we can show you how!

~Jim Hole

Now fully stocked on all Corona pruning shears, loppers, saws, pole pruners, and hand pruners.

Now fully stocked on all Corona pruning shears, loppers, saws, pole pruners, and hand pruners.

Fall Gardening: Moving Perennials and Planting Trees in the Fall

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At this time of the year, I get asked everyday if this is still a good time to plant.

The fact is that for many plants fall it is actually THE BEST time to plant! It's also a great time to get deals on perennials, trees, and shrubs too!

Why is it the best time to plant? Well, with plants preparing for winter, there is no energy being used for new growth. Soon leaves will start to drop and the sap stream will stop. All the plant's energy will go to root development and the soil is still warm enough for plants to settle in.

That said, plants that you buy in a garden centre will probably be "root-bound" after growing in a pot for a whole season.  For this reason, it is really important to break up that rootball at planting time, to give the plant a chance to develop new roots. Massaging the rootball lightly will likely not be enough. If necessary, take a knife to loosen the roots and really roughen them up. Make sure you have watered the plant before you do this.

  • Fall is also a good time to plant, move, or split most perennials.You can still see what is growing where and it is easy to remember what was not working well.
  • Most perennials can be split and re-located in fall or spring, but for Peonies, Bearded Irises, and Lilies, fall is the very best time.
  • Tender perennials and grasses are better relocated in spring. Shrubs and most evergreens can be re-located till mid-October.
  • I would not plant or relocate cedars any later than the end of September. 
  • All other trees can be planted or transplanted for as long as the ground is soft.
  • If you have any hardy perennials or shrubs in a pot or planter that you would like to survive winter, then this is the time to plant them in the ground. In our harsh Alberta winters plants will almost never survive in a pot.

When transplanting, mix in some Sea Soil into the new hole that you've dug.Sea Soil is our best compost here at Hole’s. It is made from composted forest fibres and composted fish. It works well for just about any plant and I love the smell of it that reminds me of forest in fall.

Finally, remember to water your plants during fall and soak everything really well before the ground freezes, usually towards the end of October.

 
~Maria Beers
 

 

Maria is a landscape designer trained and educated in the Netherlands. She owned a landscape design business for 10 years before moving to Edmonton in 2005 and joining the Hole's team. Interested in booking a landscape consultation with Maria? Click here.

Tips on choosing a tree for your front yard

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Choosing the right tree for your front yard is an important landscaping decision.  Maybe you've just bought a brand new house and are trying to figure out what to do with your landscaping? Or perhaps you just took down a 50-year-old birch tree and need to replace it with something?

Whatever your situation, here's how to find the right tree for your yard.

Firstly, there are a few factors to take into consideration: 

  • The size of your lot 
  • The shape of your house 
  • The colour of your siding
  • What type of trees are planted nearby

Next, here's a designer’s trick I use when helping people plan their landscaping:

  • Stand on the opposite side of your street, and take a photo of your front yard, including your house.
  • Get a piece of transparent tracing paper and put it over your photo. With a pencil and an eraser you can experiment with different shapes of trees, different sizes of trees, and even different placements.
  • Once you have found your favourite shape and size of tree, take good note of the location you would like to plant it in. How many hours of sun would the tree get there?  How exposed will it be to cold northwest winds? And how is the drainage in that particular spot?

By completing these easy steps, you'll have gathered all the necessary information to go tree shopping. The only thing missing is to visit us, let us know what you're looking for, and we'll help you find a tree that matches those needs.

 

Maria is a landscape designer trained and educated in the Netherlands. She owned a landscape design business for 10 years before moving to Edmonton in 2005 and joining the Hole's team. Book a landscaping design consultation with Maria Beers