DEFOLIATION

NOTE: This article is a consolidation of both a presentation given to Buffalo Bonsai Members by fellow member Dan Trzepacz and the second part shows the results that can be achieved with using the rules given in Dan's presentation.

Presentation Summary:

"Defoliation" is the removal of leaves from a tree other than the natural leaf fall, on DECIDUOUS trees. This technique is practiced for many reasons:

When you defoliate a tree, do not cut the leaf off too close to the branch. Doing so could damage the bud for the new leaf. A good rule of thumb is to cut the petioles (leaf stems) in half. The portion of the petiole that remainswill dry up and fall off by itself.

After defoliation has taken place, no water will be lost through the leaves and the tree will not be drying out as rapidly as before, so be especially alert to not over-water. However, frequent misting of branches will definitely encourage bud development and regrowth of leaves.

You also do not need to fertilize until the new leaves emerge. In addition, while the tree has no leaves on it it's a good time to get a second chance to trim and wire your bonsai.

The Results That Were Achieved Using The Above:

Five trees were used in the defoliation exercise. A small ficus, and four medium sized bonsai; a hornbeam, and three maples. The defoliation process took place between June 13th to 16th. Leaves started to emerge on the bonsai between June 21st to 26th. The final results shown were on August 5th.

When the trees were defoliated, they were trimmed back to reduce their size and silhouette as much as possible. In addition, wiring was applied where required. Measurements were taken of the leaves that were removed. The measurements were for the typical size as well as the largest leaves removed for each tree. These were then compared with the final leaf sizes on August 5th. The results were amazing. Leaf reduction was generally from 50% to 60% smaller. The least amount of reduction was 36% for the trident maple, which had the smallest leaves to begin with. To see a larger version of the chart or any of the photos below, simply click on it.

Chart

In addition, back-budding on the branches significantly improved the leaf pads on each branch (see photos of red leaf maple below).

Backbudding July 7th
Developed foliage pads in August
Back-budding on July 7th
Developed Pads in August

Ficus

Ficus before defoliation Ficus after defoliation
Before Defoliation
After Defoliation & Trimming

Ficus in August After defoliation
With New Leaves in August

Ficus Leaf Size before

Ficus Leaf Size August
Leaf Size at Defoliation
Leaf Size August 5th

Hornbeam

Hornbeam before defoliation Hornbeam after defoliation
Before Defoliation
After Defoliation & Trimming

Hornbeam in August after defoliation
With New Leaves in August

Leaf Size Before defoliation

Leaf Size After defoliation
Leaf Size at Defoliation
Leaf Size August 5th

Maple

Maple before defoliation Maple after defoliation
Before Defoliation
After Defoliation & Trimming

Maple in August after defoliation
With New Leaves in August

Leaf Size Before defoliation

Leaf Size After defoliation
Leaf Size at Defoliation
Leaf Size August 5th

Red Leaf Maple

Red Leaf Maple before defoliation Red Leaf Maple after defoliation
Before Defoliation
After Defoliation & Trimming

Red Leaf Maple in August after defoliation
With New Leaves in August

Leaf Size Before defoliation

Leaf Size After defoliation
Leaf Size at Defoliation
Leaf Size August 5th

Trident Maple

Trident Maple before defoliation Trident Maple after defoliation
Before Defoliation
After Defoliation & Trimming

Trident Maple in August
With New Leaves in August

Leaf Size Before defoliation

Leaf Size After defoliation
Leaf Size at Defoliation
Leaf Size August 5th

 

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