Kwanzan Cherry trouble

Question

Hi there. I’ve planted a Kwanzan Cherry in Florida, zone 9. The tree gets south exposure, so I know that planting it in this location was going to be a toss up. Having said that, the tree at the beginning of Spring took off quite well. Branches towards the top of the tree formed, and grew somewhat fast. The leaves formed beautifully, and it seemed quite healthy.

A lot of growth was taking place, all over the tree trunk. At this time (late Feb/early Mar), in an effort to motivate the tree to continue focusing its growth near the top, I pruned off any new branches trying to form (two or more were halfway up trunk, and a couple more were towards the bottom of the trunk). Soon after I pruned, the results were not what I had anticipated. The tree did not grow any more towards the top. Instead, it halted growth all together. Soon after, the newly formed branches and leaves towards the top began to look stressed. It was at this time, that I began to regret the pruning I had done to the lower branches. Fast forward another month or two, and now there is some growth starting towards the very bottom of the trunk. The leaves towards the top are turning yellow and brown, then falling off.

I applied an organic fertilizer (dry/granulated), early in spring and then most recently (during April and early May) used a liquid fish fertilizer mixed with water (municipal water sourced).

Timeline:

Dec 15th – Planted
Jan 10th – Pictured before first foliage appeared
Feb 10th – Pictured with new growth all over trunk, before pruning of lower growth that occurred late February/early March
Feb 13th – Continued new growth on tree shown in pictures, again before pruning of lower growth took place
April 6th – Tree pictured after pruning took place. First signs of stressing appeared at top of tree around this time.
April 11th – Tree showing increased signs of stressing.
May 5th- At very bottom of trunk, new foliage emerges, that growth remains. Growth of this foliage is very slow compared to past growth. I do not intend to prune any more of this lower growth.
May 27th – Picture of a leaf that has fallen off top of tree.

My questions are:

1) Does the leaf shown exhibit a bacterial or fungal infection?
2) Have I badly damaged the tree by pruning much of it’s lower growth?
3) Is there anything I can do to help the tree at this point?

Answer 1

It seems like the tree may have died off, perhaps due to stress.
Kwanzan Cherry Trees need very little pruning.

The bottom growth is likely growing from the root stock; and it is most likely of a different variety then the tree.
Here is an article that will refresh you on the care requirements.

https://www.gardeningknowhow.com/ornamental/trees/ornamental-cherry/kwanzan-cherry-trees.htm