croton leaves malformed

9 years ago

fl is croton country. so i figured i can get a good answer here :).
i have my croton outdoors now (wintering inside since i am up north).
i had a greenhouse thrip infestation that spread when i bought a new plant. so i had to cut off all new growth on my crotons and used systemic too to prevent more damage. there are still some thrips around, though not much. i am also spraying with insecticide soap and also neem. and hoping to be free of them eventually.
i thought it was ok - the new growth started, but came out all twisted. i was monitoring, i did not see any mites. but i suspect that's what caused it.
i have started spraying neem/insecticidal soap into the growing tips. there are still new leaves forming. but it's too late for some.
i checked the undersides - i don't see mite damage and i see some thrips damage, but only on few leaves. most leaves undersides are clean.
i also have similar malformed twisted leaves on a citrus.
just today i was in HD and noticed a croton that had lots of twisted malformed leaves like that. and that's a new plant...
so my question is: is it definitely mites? obviously, it happens a lot, if even new greenhouse plants are like that.
i had my crotons for 4/3 years and it did not happen before. i did have mites in winter at times, but that did not affect the new leaves like that.
could it be something else?
and what to do to prevent it?
if you could see it on the 2nd pic there are a sort of lesions on the leaf : twisted raised areas.

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petrushka (7b)
Original Author

9 years ago

i have sprayed them with neem continuosly for sev years - at all stages of leaf development and at all times of year - they have never done this before. so it can't be neem.
so then insecticidal soap? i find it hard to believe!
i did spray with it once after i cut out the infected leaves with tips (thrips). and then i did not touch them until i saw that the leaves were coming out twisted, almost a month later. it was 90F for a week and dry - 40% RH outside, that's why i thought about mites... though i do not see typical mite spotting on the undersides.
crotons are in bright shade, no sun, no burning.
i might've misted with 1/3 solution of rubbing alcohol. but i wiped the leaves with it before and had no problem. of course they were mature, toughened leaves.
i know you have a tonne of crotons in your garden, i've seen your wonderful pics. i figured if anybody, you will know for sure.
i do not spray with systemics - i put them down on soil - houseplant imid, quite mild (done it many times too before, no problem).
what is left - mild kelp solution foliar spray? i am not sure, i did use it like 2 weeks ago , but the leaves were already twisted by then.
so what do i do if i have greenhouse thrips ? or mites? i have a balcony up high. no hosing down. only misting and shower indoors. so that's the only thing i can do when leaves are forming?

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Comments (8)

fawnridge (Ricky)
9 years ago
The damage is due to the use of chemicals - natural, organic or not - sprayed onto the new growth. The next set of leaves will come out normal if you refrain from spraying them until they are mature.
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fawnridge (Ricky)
9 years ago
Make a solution of water, garlic juice, and dish detergent. One gallon of water, 1 cup of garlic juice, and 1/2 cup of dish detergent. You can get enough garlic juice from a jar of minced garlic.
petrushka (7b)
Original Author
9 years ago
wow, i hope it will air out soon... DH will be freaking out sitting in garlic wonder-land :)! but i'll try to mist only the growing tips to contain the goodness!
sorry, that i am digging still, but you do think that i cannot spray neem solution on very small leaves? can i contrive to cover them up and spray mature leaves only? - mites will eat them up otherwise....
i do not spray light horti-oils : had a very bad experience with them before: killed my other crotons. neem could be considered a light horti-oil, right? but i think it's a very mild solution. and i spray strictly indoors, in the shower and then follow up with the water rinse (plus 1.5tsp of 3% peroxide to 1qt) to wash off some of the residual neem.
but sometimes i do not rinse.
it never never before caused a problem...
fawnridge (Ricky)
9 years ago
Crotons have a totally unstable genetic structure. You can look at them cross-eyed and the leaves will go nuts. The younger the leaf, the more likely it will sport something different than the original plant. I would simply wash your leaves off in the shower and forget all the chemicals.

And just because it worked in the past, doesn't mean that it work the same all the time with a Croton.
petrushka (7b)
Original Author
9 years ago
ok, thanks!
i will try harder to keep them clean. and be very watchful about spraying anything.
i did not know they were that sensitive!
greenie1_gw
9 years ago
I agree with Fawnridge. I have several big old crotons and they are very hardy and seem to do best when I just leave them alone. I have used Bayers Tree and Shrub on the rare occasion where there's a problem. If you really like crotons, here's a good link: http://www.palmpedia.net/forum/index.php?forums/the-croton-society.26/
petrushka (7b)
Original Author
9 years ago
thanks, that's a great site! i'll be doing some reading...:).