White stuff on tips of leaves Crepe Myrtle

[Rhodie Ranch]

Yesterday I noticed that almost every new leaf on my bush crepe myrtle has small white stuff on the tips. Its kinda granular, comes of easily, and there is no discernable organism inside the white stuff. The stuff is not on mature leaves or on the branches. This bush is now about 2 years old, gets morning sun, and is thriving! Suggestions?

 

[Smart Red]

Wish I could help, but I lost my crape myrtle in the drought of 2012. All I know about them -- other than they need to be wintered in a sheltered spot -- is that I want another one!

The only thing I know of that causes a granular white residue is drips left by sucking insects. When removed is the leaf all green again or is there signs of damage to the leaf tip?

 

[Rhodie Ranch]

no signs of any damage. Clean, not eaten, no veining, healthy healthy healthy. We've had crepe myrtles, both shrubs and trees and this is a first for me.

 

[thistlebloom]

This is a total shot in the dark, but I wondered if it could be minerals the plant is drawing up from the soil, and exiting through the leaf cells, maybe gathering at the tips as it dries? Maybe it's most obvious on the new growth as it's growing faster and more tender?

 

[thistlebloom]

@murphysranch, I think I've found an explanation for the crusting on the leaf tips.
It is in volume 12 of the Annual Report of the Michigan Academy of Science.
I wasn't able to excerpt it, but I'll try to give you the jist of it.

Basically what it said is that leaves are designed to transpire and give off water vapor. During periods of "high activity"
(growth) they give off a lot more water vapor than usual. During the day the transpiration clicks along great, but at night the roots continue to do their job of pulling water in and transpiration through the stomata is reduced. The plant has a mechanism to reduce the pressure this creates through water-pores, which excrete the liquid.

If the air is dry, the liquid which contains minerals (putting it simply) evaporates quickly and leaves a crust.

So, that's probably what's going on with your Crepe myrtle. Nothing to worry about.

 

[Rhodie Ranch]

Very interesting! Who knew about mineral deposits and transpiration. I'll keep an eye on it, as its otherwise very happy. Thank you for your research!