Crape Myrtle / Lagerstroemia Indica Timing

Hey Everyone!

I have a Crape Myrtle located in Central Florida, and I have a question regarding pruning timing. The tree will be transitioning into the refinement phase of growth in some areas. In an attempt to consistently progress the tree while staying horticulturally sound, how do I dial in the timing? I only prune in an energy positive state and I look for indicators like formation of leaf cuticle, color change and growth suspension. What is throwing me off, and what I would like dial in, is new shoot lignification. I remember in the bald cypress stream, Ryan Neil, mentions the importance of lignification in new cypress shoots or color change to straw before pruning in order to create bifurcation. New Crape shoots are very soft and fleshy, long after leaf hardening and cuticle formation. Should I wait for shoot lignification, essentially lengthening each flush of growth or are the typical hardening signs enough?

Does anyone have any experience with a pinching strategy similar to maples?

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I have done pruning in both manners that you have described. I have found that pruning before the actual stem/branch lignifies will eventually cause the tree to weaken. I would prune your crape myrtle in this manner. Let grow and elongate, wait for the base of the shoot to begin to lignify (it should be firm, non flexible, and be different color as compared to the soft fleshy often red stem of new growth.) Let the branch lignify to about 2-3 nodes then cut back to desired node or nodes. For me, this would be to the 1st or 2nd node.

This next part is important to assisting in smaller more compact growth in crape myrtle. Do not fertilize after pruning! Let the new growth once again elongate, harden off, then prune back to 1st or 2nd node again.

Now you would be developing a 3rd flush of growth. If your growing season allows; you may let new growth elongate, harden and prune once more. Again, do not fertilize.Wait until this 3rd flush grows out and hardens off.

At this time you may begin fall fertilization, you may even get some more elongation and flowers in the fall. I would not worry about this and enjoy the often white or pink flowers. Minimal fertilizer all through the fall.

Once the leaves drop in autumn, branches can be reduced to the more compact growth that have been created via pruning and appropriate fertilization during the growing season.

Crapes are very vigorous so I keep the fertilizer to a minimum, otherwise, they become unruly.

I remember hearing Ryan say once, “Fertilization should be done in accordance to the highest level of refinement.” So if your tree is in a state of partial refinement then gear your fertilizer to obtaining better ramification. This would mean less fertilizer, less often, and at the appropriate time.

Hope you find this helpful. Good luck and Bonsai On!

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By the way, that’s a really nice specimen you have. The base and deadwood features really give it some character.

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Excellent write up! Only thing I can add is that I’ve found that I’m not able to maintain much of the third flush in my growing area. By then winter comes in and zaps the finer twigs of the 3rd flush. With dbcharles being in Central Florida they likely can get away with it.

I’ve only gotten mine to reliably ramify via the 70% partial defoliation route. Mine is still in development, but this is what I’ve been able to get after one year. I’m allowing the basal growth to thicken the base of the clump. It’s currently flushing out, but I plan on rewiring it a bit this week as well as picking leaders and doing the angle cuts to introduce taper.

That’s a sweet tree btw, DB.

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Thanks for the responses, this is exactly what I was looking for. @ndavila80 I originally pruned pre lignification and I did notice an overall reduction in vigor so I’m glad you suggested waiting a little longer before pruning. Quick question regarding fertilization. Should I refrain from fertilizing until fall ? Down here in Florida the growth is so vigorous as you already stated, that I’m always in the brink of out of control. Should I choose a very low balanced fert or something higher in P or K? Secondary stage growth seems to be my comfort zone haha. I guess I’m afraid of never leaving this stage.

Between that and some partial defoliation I think I can make some great improvements going forward. I’ll update the photos and the end of the season. @Bonsai_Bentley you have a fantastic clump style Crape, great nebari forming. Do you have a progression thread going ? I would like to follow that to keep a visual on your technique.

@ndavila80
…sorry I misunderstood originally. Disregard the fertilizer question.

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Nah, no progression thread. I do occasionally post on instagram or you can join our bonsai discord. I post in there a decent amount as well.