Alberta Spruce have a poor reputation as bonsai. In their natural form they are very tree-like and as a result, they often appeal to novice enthusiasts who then struggle to prune, wire and style them into to shape as bonsai.
My experience with these trees is that they require thorough wiring to form a good quality bonsai and they require repeated re-wiring before the branches hold into their new postions. However, pruning is very straightforward and if carried out correctly, tight pads of foliage can be created in remarkably little time. For more details on these techniques please see Picea Pruning,Wirinng and Styling
December 2005: The main two trees in this group planting were a lucky purchase. I discovered them growing in two half-barrels at a nursery that was clearing out an old display for just £6.
As can be seen in the image above, they both look very much like 'proper' trees as they are. So why prune or style them at all?
Both trees have an immature 'pointed' apex and the foliage mass dwarfs the relatively thin trunks. To rectify these faults, both trunks need to be reduced in height, their branches shortened back and the apex rounded. Unfortunately, this work results in two very ugly looking trees until they are then styled!
Having pruned back the foliage hard, reduced the height of the trunks so that the trunk height to trunk diameter was roughly 10:1, the trees were planted into a shallow wooden box.
September 09 2006: The trees were allowed to recover through the Spring and Summer and were well fed. By September, I had decided to use the two trees to build a group planting; late Summer/early Autumn is a good time to prune and wire Picea. In the UK, repotting can also be carried out once the heat of the Summer has subsided but the first frosts are at least 6 weeks away.
The trees were pruned back again, thinning away branches that were not required for the final design, while trying to retain branches that had foliage closest to the trunk.
The sap of Picea will still bleed at this time of year (after pruning heavier branches), wounds can be effectively dressed with vaseline or to ensure that the sap stops flowing immediately, a little wood hardener can be applied to areas where the sap is weeping. This hardens the sap and stops it running.
The trees were wired and planted into a large bonsai pot I had previously acquired (not shown). The roots were arranged into the pot but not pruned.
September 20 2006: With the two main trees in the group planting completed, a further 5 trees were purchased.
Each of the smaller trees were pruned to reflect the same dimensions of the two main trees. These trees were intended to be placed in the background of the planting as though seen in the distance; for this image to work, the scale of all of the trees in the group had to be equal and so the trunks were carefully pruned to the same ratio of 10:1.
Finally, the five 'background' trees were wired and roughly styled before being added to the group planting. Pruning severely, wiring and potting up over the course of a few days is very stressful to trees of all species; Picea glauca are very tough in my experience but these trees will require some protection from any extremes of the weather for a few weeks until they recover. It is recommended to divide up this amount of work over the course of one or even two years to ensure your tree remain in good health.
September 23 2006: After a few days of tidying and lime sulphuring the deadwood, rearranging the branch placement of the trees and adding some moss and stone, the group planting is finished for the time being.
While I had originally planned to add 5 background trees for a 7-tree group planting, when it came to planting up the group, I found that a total of just 5 trees made a cleaner and less cluttered design.
The height of the tallest tree is 19"/47cm; the pot by Erin Pottery is 22"/54cm wide.