In the world of horticulture, there have been many giants – landscape designers, plant breeders and teachers.   I am grateful for meeting my 'giant' in horticulture – Dr. Linda Chalker-Scott – during her April visit to Thunder Bay.   As I've worked in my garden this season, I've reflected on and applied the advice she shared with gardeners in my community.

I want to report on a technique that Dr. Chalker-Scott champions – the bare root transplanting of shrubs and trees.  

Many landscapers will consider this controversial, but I think it is beneficial.  I've tried it with newly-purchased potted shrubs and with a shrub that needed to be moved.  From what I can see, these plants are doing well, thanks to lots of rain, cool days and this transplanting method.

I needed to relocate my dwarf willow (Salix integra ‘Hakuro-nishiki Dappled Willow’) to a shadier, more moist location.  I dug up the willow and was shocked to see the root ball looked exactly the same as it did when I planted it a year ago.  The root mass was the shape of the pot it had come in; they had not spread into the soil at all.  How I wish I had a picture to share!  

Here's how I used the bare root transplanting method to remedy the situation. 

I placed the shrub in my wheelbarrow and gently washed the soil from the roots.  I checked the roots for structure and health.  I pruned away some of the bound up roots and untangled the rest.  I dug a shallow hole in the new location, and without amending the soil at all, I arranged the shrub with its roots radiating out like the spokes on a wheel.  I covered everything with soil, taking care that the shrub was planted at the same level as before, then watered well. 

To my amazement, the willow has shown no signs of stress; instead, there is plenty of new growth.  I know that below ground, my willow is well-supported and its roots have ample opportunity to draw nutrients from the soil.  I am keen to see how it progresses this season and beyond.

On to the planting of newly-purchased shrubs. 

My neighbour asked me to help with the placement of three new shrubs.  Armed with my new experience, I felt pretty confident we should use the bare root method.  As we removed the purple-leaf sand cherry (Prunus × cistena) from its pot, I could see that the roots had already begun to curl and harden within the pot – not a good sign.  Left as is, the woody, curled root would likely continue to grow in a circular direction around the root ball.  This is how shrubs and trees can be girdled by their own roots. 

I pruned back this circling root and proceeded as before – planting in a shallow hole, watering in with the water left from the root baring process, and covering over with soil to the correct depth.  Voila, a happy shrub!

You can review the bare root method in more
detail in Dr. Chalker-Scott's excellent slideshare,
"Take It All Off" (file download below).

Dr. Chalker-Scott, the Extension Urban Horticulturist at Washington State University, was a delightful guest.  We toured some of our northern sights. 

Fortunately for gardeners this talented teacher shares her advice freely on her website, The Informed Gardener, and in her books.  As well, you can find her among the horticulturists at The Garden Professors.  Her useful perspective on landscape plants will get you doing things differently.  There's still time to plant a shrub or two this season.

Trees make a city whole – yet how many of us take our city trees for granted?   Trees work for us in many ways, making our urban spaces cooler, more inviting, and healthier.  

We are starting to reach beyond air quality, water quality and erosion control in our understanding of the known benefits derived from trees.

A 2015 study using data from Toronto published by a team of University of Chicago psychologists found that street trees can impact our perception of health.People living in areas with more street trees reported better health perception than those in neighborhoods with fewer trees.  Regardless of their actual health, they felt they were healthier.  
It turns out they really were healthier; these respondents had fewer cardio-metabolic conditions such as diabetes, heart disease or stroke.

As we learn more, we can't deny the importance of our urban forest.  In Thunder Bay, the urban canopy cover is estimated at 20-25 percentage of the city's land area.  (In Toronto the percentage is about 26 percent.)   The city's 2015 tree inventory lists 30,392 trees on public land.  The vast majority are street trees. 

Soon trees in your neighbourhood will be leafing out.  So here's a question ...
What can you do for the trees in your yard, on your street, and in your city?

Learn to prune young trees
Since 2011, the City of Thunder Bay has offered residents an opportunity to learn how to train young trees through the Citizen Pruner Program. 

The training – given in 3 sessions – focuses on the pruning of young street trees.  It includes:

• proper pruning techniques
• the principles behind pruning
• the identification of trees in our urban forest
• the analysis of tree structure
• the basics of tree disease
• pruning equipment use and function

Best of all, the sessions are guided by a professional arborist and city parks staff.  All equipment is provided – even safety vests!

Thunder Bay sought assistance for the program from Tree Canada and TD Green Streets initially.  It is the only city in Canada with a program that involves citizens in the ongoing care of the urban forest in this way. 

The rationale for the program is simple.  The cutting or removal of mature trees that are diseased or unsound has to take priority for city staff, especially when public safety is a concern.  Less time is available for the care of young trees. This is where Citizen Pruners can help.  Street trees greatly benefit from pruning when they are young.  If structural problems are corrected early in a tree's life, it is more likely to grow into a healthy tree that will live for many years.

Citizen Pruners at work
Once their training is completed, participants take part in evening pruning sessions – under the direction of city staff – in designated neighbourhoods.  Teams of 2-3 people can prune several trees in one evening.  

All participants are expected to take part in at least 3 work sessions between May and September.  Volunteers find coming out to several sessions is the best way to gain confidence in assessing a tree's pruning needs.  Besides, working together is fun.  Citizen Pruners from previous years also join in, helping new volunteers to learn the ropes.

Picture it – an impressive 89 volunteer pruners have been trained to date; more than 730 trees have been pruned since the program began. 

This could be you.  You can make a difference in the health of our city trees.

How to get involved
The 2016 Citizen Pruner Program gets underway April 14, 21 and 28. The program is open to anyone 16 years or older.  A $25 registration fee covers equipment.  Participants are expected to attend all 3 training sessions and commit to 3 work sessions.  To register call (807) 625-8463 or (807) 625-2696.

"Large streams from little fountains flow, Tall oaks from little acorns grow."
  ― D Everett,  The Columbian Orator, 1797

Trees are a necessity for the human soul. Trees give us health, beauty and cool respite.  They give us a sense of place and they teach us about the passage of time.  If we were wise, we would plant many more trees than we do, for every newly-planted tree contributes to the renewal of our shared landscape.

I learned to love trees first from my mother and later from the foresters I've come to know in Northwestern Ontario.  The passion of tree developers like Rick Durand of Bylands Nursery in BC have also inspired me to value trees.  A well-tended tree may well grow to be the soul of a garden.

Lest you think this will be a wholly poetic post, let's shift gears and talk about trees that can withstand the harsh weather of a northern garden.  Happily, there are many species that will give us shade, form and privacy. 

One of my favorite trees is bur oak (Quercus macrocarpa).  It is pictured above in its happiest setting – growing out in the open in a grassy space, which is the modern equivalent of its natural prairie habitat.

Could you grow a bur oak in your yard?  Absolutely!  As a specimen tree that gives shade and character in the urban landscape, I think it is a fine choice.

Bur oak (also spelled burr oak) is a small to medium sized deciduous tree that can grow 15 to 20 m (50 to 65 ft) tall.  It is considered a slow-growing tree, but once established it will adapt to dry and moist conditions.  As the Manitoba Forestry Association explain in the Think Trees seedling catalogue, "A deep & wide-spreading root system with a strong taproot makes this species drought-tolerant."  This makes bur oak a good choice if you are establishing a moisture-conserving landscape. 

Remember that 'sense of place' I mentioned?  Bur oak is very long-lived, surviving up to 200 years, given care and good growing conditions.  There is no doubt a bur oak is a heritage tree worth planting for future generations.

In a brief paper by Mary Ann Riley (Kemptville College), I learned that "bur oak grows best on deep, dry, rich bottom lands.  Its preference is for well drained sandy or clay loam soils.  It also occurs on upland limestone soils and at the northern limits of its range, on shallow soil over granite bedrock. Trees may be stunted on exposed shallow soils."  Now this sounds like northern Ontario, doesn't it?   We count on tenacious trees, even if they do get gnarly.

So let's summarize ...

As we step towards Arbor Week, why not think about trees.  Maybe a bur oak is the tree for your yard.  Now – while trees are dormant – is the best time to plant.  Where could you plant a tree? 

What do you think?  Is a tree museum a harbinger of things to come in our world?
View more of Enzo Enea's design –  'garden architecture as an extension of the living space'