Hi, Stephane -

Adeniums are meant to be and thrive in high lumen sunlight. There are many reasons why this could be happening. Whatever the case, rest assured that adeniums are resilient ... Your tree will bounce back and produce beautiful flowers for many years once the issue is corrected.

- Check the underside of the yellowed leaves (try to post a closeup) for mites, webs, scale, etc. If you find any pests, wash off the entire tree with sudsy water (use a mild dishwashing liquid). Be sure to work it onto each leaf and RINSE thoroughly. Keep an eye out for recurrence.

- This particular tree may have been raised under tarp and is not accustomed to sunlight, resulting in sunburn. In that case, it will drop all the old leaves and new, stronger leaves will develop. Water until runoff when the top 2 inches of substate feels dry. Use your finger to check soil until you establish a watering schedule for this particular tree, in its particular pot, for that particular soil, in your particular climate. All of these play a critical role and work together.

- The substate may not be quick draining and remains too wet for too long. That is never good for this or any succulent. In this case, uproot the tree to check root health (should be done yearly, anyway). Wash off all old soil and post closeups of the root system, front & back. Check for black or soft spots. We'll go there if & when. I use fast draining cactus soil mixed with perlite.

- Over-fertilization (too often, the wrong NPK ratio, overdose of high concentration, splashing) will cause leaf burn. Adeniums should be fertilized via bottom watering weekly at 1/4 strength (or less) with one or both of two formulations, in alternating weekly applications: NPK 20-20-20 / 15-15-15 / 10-10-10 for leaf development and NPK where the P formulation is higher, such as NPK 6-12-6 (tomato food), for bloom development. I use 20-20-20 once a month and tomato food the other three weeks of the month at 1/4 strength.

I'll end here and let others chime in. I hope you find this useful. Happy growing & learning!

You have had so much rain as of late your plant maybe adjusting. Give it as much sun as you can and follow LL's advise. A pic close up of the leaf and stem tips may help. I know you get a lot of scale in your area. Is the cadieux firm? Can we see the whole tree? As said they are hardy trees and put up with a lot. In your area you must have quick draining soil.

Thank you for your replies. I just took a look at a small adenium next to the big one and this is what I saw. Those little yellow things move too... gross lol

I just googled those and apparently they are called Aphids. Is this right?

Before I look for a remedy online, do you guys know something that really works?

Stephane

Thank you Marie! I'll make that mixture in a bit and use it tonight.
For now, I just used a sprayer that has a lot of pressure and blasted those little suckers.

Stephane

Yep you have aphids. wash them off with the soap. There will still be eggs so do it again and again. Are the plants in the area you keep them also infected? If so I might use a systemic insecticide. Or a light weight spray. So as not to burn the leaves. Try the soap wash first.

All the adeniums are in my greenhouse. I checked all of them and so far I'm only seeing 3 who are affected by the aphids. I just sprayed them with the soap solution and tomorrow I'll water them and rinse them off with water the sun comes up.

I guess I'll keep a close eye on those. Thanks a lot for your help, I'll keep you posted :)

Stephane

Aphids suck!!

Stephane,

Just pick off visible ones with wet paper towels and wash the plants down with soap & water. Also, please isolate the infested plants or everything will get infested.

If it's warm in your region, move the pots to sunlight ... these bugs hate sun. Check daily and repeat treatment until the problem has been eradicated. I've actually gotten rid of these with one treatment and just getting the plant away from where it got infested.

Thank you guys. I actually got most of them by hand. Then moved the infected ones outside (out of the greenhouse) where I washed them down with water and soap.

Tomorrow I'll rinse them and hopefully it'll be fine after 1 treatment.

Stephane

They suffocate on the soapy water. Even the ones you don't see. Good luck hope they stay away.

If you do end up needing a chemical look for active ingredient imidacloprid

Hi guys,
Water/soap was a success for now. This morning, I rinsed all the infected plants and I just checked this evening, and so far, I haven't seen any of these Aphids. I'll keep checking of course and repeat the procedure as soon as I see something.

Now if you could help me identify this bug, I would really appreciate it :) It's everywhere and they are eating the leaves of everything.

Stephane

Looks like a tripp to me, but i'm not too keen on IDing bugs. Post a closeup (just crop) on Integrated Pest Management:

http://forums.gardenweb.com/forums/ipm

what's

Very interesting and readable

دی کرومات پتاسیم