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.
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).
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.