Yellow desert roses leaves may mean you could be over-watering your plants. There's an easy way to recognize this. Let's see some possible reasons why.
Reason #1: Over-Watering
Firstly, you can have a look at the tip of the leaf:
The yellowing starts from the tip of the leaf and slowly spreading inwards. Initially, you'll see the leaves getting kind of darker–like it's slowly bruising in. Then some days after that, it will turn more yellow/brown and dry.
In this case, you can save it by reducing the water amount immediately. Or try sucking out the moisture using some napkin, Q-tip or sand. If your trees are bigger, you could get new soil for them. Be careful with shocks during the transplanting process.
The reason why many people (like us) overwater the plants may be because the experience of spraying or watering our plants feels good & could sometimes be addicting. It's easy to go overboard. We try to water less by making the spraying bottle slightly harder to press or put in less water.
In another case, if the yellowing starts from the inside of the leaf, as you can see in the picture below, it may reflect something different:
Reason #2: Under-Watering
If the yellowing starts from the inside of the leaves & spreading out to the tips, this may suggest lack of sunlight or under-watering. To make sure, check the soil condition & look at the adenium overall body. If the soil is dry & the adenium body looks wrinkled with non-glossy leaves, then the plant may be thirsty.
Sometimes when people want the adenium to go dormant in the winter, they leave it inside the house & stop watering. This lack of sunlight triggers the yellowing & dropping of leaves.
Under-watered adenium is easier to save than the over-watered one. Give your babies some sprinkle of water. Then move it out to some area with more sun during the day gradually but not too rapidly. They will recover.
From what we've explored so far, the basic idea of yellowing may be simplified as:
If we look at the leaf as our little water measurer, it may be telling us what's going on inside the plant. If the yellowing starts from the tip in, it may be too much water. If the yellowing is from the inside out, this may mean too little water.
Please also note that these are strictly observational notes from experience and we are by no means experts on this. Your experiences may differ a little bit.
From what we've seen, the good news is that even after all or most of the leaves have turned yellow the plant will live on. It will not die so easily. It will shoot out green leaves when the conditions afterwards are sufficient.
And these yellow dry leaves are tough survivors on adenium seedlings. Unless we pluck them off by hand, they will remain hanging on the stem for quite a long time. They look like thin dried brown packaging paper.
As an analogy, the yellowing of adenium leaves may be like the shedding skin of a snake. It only makes the plant stronger as it is adapting to the environment.
This is one of the amazing things about adenium. They are very forgiving. We can make mistakes, learn something and try again. It's okay.
The third possible reason could be:
Reason #3: Natural Yellowing
If you try touching the yellow leaves and they fall off immediately, this means it's natural yellowing. The leaves are in its natural cycle to turn yellow after flowering & everything is okay. You don't have to worry too much in this case.
Another sign to tell you that it's natural yellowing is when you touch the caudex (the base) of the adenium, it will be full and hard–not wrinkled and soft.
Some growers notice that natural yellowing happens often during the rainy season–even with very well-cared-for plants. Some variety shows this reddish tint on the leaves before yellowing and dropping:
Yellowing goes from the lower leaves all the way up to the top leaves of the branch. As the lower leaves are older leaves. This is the adenium changing leaves in its normal cycle and you don't have to worry too much about this. Trust the process and it's all good. You can use the fallen yellow leaves as mulch or fertilizer for the plant.
Going Into Dormancy
As the adenium go into different degrees of dormancy in autumn, their leaves will turn yellow and fall off. This is visible in varieties like Adenium Boehmianum and Adenium Swazicum with a complete fall-off of the leaves.
As the autumn equinox is approaching, the plant may be letting go of older leaves in response to shortening (more cloudy, darker) September/October days. So if this is the case, it is a natural cycle. New, green leaves will grow out again when spring comes.
Reason #4: Sun Stress
When it's summer or there are heat waves passing by, the yellowing of adenium leaves may be they are putting on sunscreen or sunglasses to protect themselves. The yellowing helps reduce the excess amount of sunlight the plants take in. As the hot season is over, the leaves will gradually turn green again.
Also, in summer, keep the plants facing the same direction. If rotated, the side that gets more shade may not get adapted yet and intense sun can burn it severely. Especially the approaching autumn sun when it's low in the sky but still very strong.
After winter storage, when the plant first meets its first sunlight again, its leaves may scorch (get sunburned). This is not a severe issue however because new sun-adapted leaves will begin to grow out soon.
Also Check the Roots
If, however, you press down on the leaves a few times but they don't fall off instantly, then check the roots. It may be root fungal diseases or too many string roots. The good bits may not get carried up to the leaves, causing yellowing.
You can see some white fuzz start colonizing on the adenium root above. From one grower's experience, this is one early signs of the root or caudex about to rot.
To save it, you can dig the plants up. Cut off some mushy roots. Then dry it under the sun. Remember to apply some sealant to help the open wound. Let them rest for 7-14 days. Replant your trees in new soil for recovery.
If you want a closer look to deal with root rot, check out this post below:
>> Link Blog post: Adenium root rot how to save
Pests & Fungi May Cause Yellow Leaves
If the adenium has been infected with pests or fungi, you may notice some tiny dots on and under the leaf surface. Compared with natural yellowing, the yellowing caused by pests has a brighter yellow all around the leaf.
If natural yellow leaves fall almost instantly on a gentle touch, the infected yellow leaves may not. Even if you push down on the leaves a couple times, they will remain quite attached to the branch.
Another way to tell if the adenium is infected by pests or fungi is to look at the caudex. In this case, your caudex may get shrunk a bit smaller. And when you touch it, you may feel that it's not hard any more but quite soft.
Here are some 'partners in crime' faces:
1. Red Spider Mites
Red spider mites are tiny red insects that can suck the nutrients out of the adenium leaves, causing them to yellow. They appear again & again each year.
You can catch these guys running up & down on the underside of the leaf like here:
Along the spine of the leaves are their white eggs. These become baby mites in about 4 days. A very fast and efficient production.
To tell whether your adenium is naturally yellowing or there might be some mites around, look for the direction for the yellowing.
If it starts from the lower leaves up, then it's normal. If it starts from the young leaves on the top, then it might be the mites. Because they love chewing on these fresh young adenium leaves.
If the condition of the leaves is not too bad, you can use a garden hose to hose them off. Or use some gloves to rub them off.
If condition is quite bad, then we might need to use some sprays. Be careful with chemical sprayers. The products that promise to kill the eggs or the babies too are highly toxic.
To rid them off safely, try this recipe:
- 3 parts boiling water
- 2 parts room temperature water
- 3 cc (3 ml) dish soap
- Optional: mint essential oil, neem oil, horticultural oils, red wood fiber
Spray this solution on the leaves late in the afternoon when the weather is cool. You can also try soaking chopped onion in water. Then, extract that juice for spraying. The idea is to make the pests 'cry' or at least 'tear up'. Termites & ants hate red wood fiber. It may be the redwood smell that keeps them away effectively.
|Cold Pressed Neem Oil|
|100% pure oil (no chemical additives)|
|Does not burn plants|
When the mama mites sense the smell of the spray (the dead zone), they will think twice before landing on the leaves & laying eggs there. The soap & oils may dissolve their soft body or protective coat. It's the smell + the dissolving that work together to keep insects away. Neem oil also messes with their reproduction system a bit.
If they have been scared by the spray once, they have the 'memory' not to find that spot to reproduce again. Hope they have a good memory. It's better to prevent this than treating it afterwards. Because you know they may come again seasonally.
Mealybug usually attacks the caudex & roots of adenium. It can make your adenium weak & lessen the overall ability to process water and nutrients. This also cause the yellowing & dropping of adenium leaves.
Here you can see the white little creature with 2 antennas:
In this case, the adenium leaves may turn duller, droopy, not glossy & more yellow. The caudex may get shrunk smaller.
To save your plants, dig them up. Wash the whole body thoroughly with water. If it's really bad, use some purple insecticide like Starkle G to spray around the roots. Leave it in shade for 7-10 days. Then, replant your tree into new soil. Be careful when using chemical insecticide because most of them to a degree are toxic.
If it's not too severe, you can also use some onion juice or the spray recipe above with the oils & soap. Spray around the leaves or pour some around the roots, where these little guys usually start their lives.
Oh and to make onion juice. You just need to chop up some onion, then soak them in water. After a few days, use that extract to spray around the plants. Onion, garlic & mustard have some sulfur in them (noticeable by their characteristic smell). It's effective for "shooing" these bugs away while not killing them.
People usually call this leaf spot. Or Anthracnose disease, caused by this long-named fungi Colletotrichum gloeosporioides penz. It looks a bit like this:
This usually happens at the beginning of the rainy season, when the humidity is high. There's excess nitrogen around the tree & that attracts the fungi. They can spread to other leaves & flower buds on the tree, often leaving black spots on the flowers as well.
Some folks just let the leaves fall. The next season, new leaves will grow out normally even though they can be quite wrinkled. Others use fungicide to kill them.
You can move your plants somewhere more dry & with sunlight. Bottom water the plants sparingly to avoid water contact on the leaves. Cut off some infected branches to avoid the fungi spreading into the tree.
>> Link Outside Blog post: What is Causing Leaf Spot and Drop On My Desert Roses?
Also, watch out for these little guys:
4. Aphids (Yellow Bugs)
Yellow bugs (aphids or sometimes called sesame bugs) love partying around the flower buds. But they come & go fast. You may see them tonight & tomorrow they're gone.
They live symbiotically with ants. They give ants the sweet honeydew juice. Ants lead them to the sweetest spots on the plant & protect them from lacewings/ladybugs. Dish soap spray & onion should get rid of them. Horticultural oils can also work.
If you want to try something different, try beer + water. Spray it all over the plant and after one day, the bugs will be gone. You can also use the mix as a prevention.
For a strong measure, growers use ant/insect sprayer. Some worry this strong mixture may burn the leaves. But from the results, it has not been so. After about 6 hours, the bugs will be dead. You'll see them stop moving around the leaves & flowers.
The appearance of these little creatures may invite some other badass guys to the garden, like this one:
A guy on Reddit told us that this is the yellow-spotted stink bug (Erthesina Fullo). We wonder if their food is the mealybugs or spider mites. This specie can be very invasive.
Around your garden, have you spotted:
5. Green Worms
Green worms will usually eat your adenium leaves. They are the offspring of the butterflies. When the worms eat the young shoots or flower buds, they'll make the shoots and buds become 'stagnant'. Which may be one reason why the desert roses are not blooming.
If you catch the worm egg or the worm poop on your adenium leaves, you have an idea now of who has been around. When the worm poop has a slightly red color to it, it may mean the worms have been enjoying your red adenium flowers. If you see the poop is slightly more green or blackish, maybe they've been chewing the leaves.
Young worm eggs have a green-yellowish color. The darker blackish eggs mean they are older and about to hatch.
Once hatched, these guys act very fast and efficiently. Within one night, one or two green worms could chew off a small adenium plant–making it go 'bald'.
Adenium leaves are the favorite food of green worms. So watch out for these guys if you'd like to keep your adenium leaves green and healthy.
Adenium Recovering: For Glossy Green Leaves
It sounds like there's too much eyeing your yummy desert rose leaves, doesn't it. Although pest control can be quite a headache, it also means your trees are attractive. Otherwise, visitors wouldn't come visit them. From one perspective, this is a natural pattern.
Also, control the water amount you give your plants. All of these yellowing signs are very similar for young seedlings & bigger adenium. Sometimes, during the rainy season, the adenium leaves may get burned at the tips. If the plant is strong, it will replace them with new leaves. It will be okay and you have nothing to worry about in this case. Make sure no rotting is happening in the roots or caudex.
Once you know where the yellowing is going & some interacting factors around it, you can save your plants. Good luck & we hope that the plants will recover. They will.
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Responses to Readers' Questions
My adenium leaf are turning yellow in September And it has no sign of rotten or under water , what to do now?
--> You could try pushing down on the yellow leaves. If they fall almost immediately then it's natural yellowing and you have nothing to worry about. Is it in rainy season? Sometimes in the fall or during the rainy season, even some strong adenium will begin to yellow their leaves naturally.
A grower shared with me that too many string roots may suck out the nutrients, causing the leaves to yellow. In most cases, if your adenium's trunk and caudex are firm, chances of survival are high. I hope this helps!
My adenium have buds but they are not blooming
--> To begin with, you could try observing the overall health of the plants. On one side, it might be that the plants are still wanting to shoot out more branches. The branches here are thick & strong with strong leaves.
On the other side, it may be lacking some good energy to get that flowering step going. The plant may have buds but you may feel its branches, especially near the top parts, are thinner/quite flimsy & with slightly weaker leaves.
In an abundance of nutrients (like nitrogen or free nitrogen in rainwater), you may see something as an "overshoot" where the adenium abort nourishing the flower buds and opportunistically continue shooting branches up. Hence, no blooming yet at this time. Using some analogies in the animal kingdom, birds with excess fat won't lay eggs soon. Worms with too much food won't multiply quickly. With the same idea, you could cut back a bit on the good stuff in the soil for your adenium. Some growers cut water for 5-7 days. They place it somewhere with good sunlight. After 7 days, water it again. And the plants may bloom again.
If it's lacking nutrients, add some more potassium for this flowering stage. Give it good sunlight and it will give you back nice flowers. Careful with spraying too much pesticides at the flower bud stage as it might burn the buds. I hope this helps!
More info here: Why are my desert roses not blooming
My adenium is getting yellow leaves from upwards to downwards and I don't water it too much, what to do?
--> If you're growing adenium in plastic pot and it is okay for you to lift it up a bit, try doing so to feel the weight. If you don't water the plant for 2-3 days but the pot still feels unusually heavy, check if the soil is too compacted. Compacted soil may leave little room for the roots to poke through, which could make the leaves yellow because of this nutrient blockage. If this is the case, you could replant it in a more airy medium or a bigger pot.
Another thing you could look out for is spraying the leaves with fungicides. Some folks spray too much of this stuff on the leaves, especially when it's hot. This will burn the leaves. Sometimes, the acid in the rain may also burn the leaves. Regarding the plant's health, non-grafted plants are usually stronger than grafted ones. Are you growing them indoors? They may turn yellow or go into dormancy without enough sunlight (or in cases, water). I hope this helps!
Why do the flowers and buds on my Desert Roses get black or dry spots on them some times the flower buds will fall off .
--> Thanks for your question. What I can say for now is that it might be the insects or butterflies "biting/stinging" the young buds. When the buds are about to form, possibly, in one grower's opinion, the plant gives off some kind of smell that attract these insects. When the insects come, taking a bite of the buds and sucking the nutrients out, the buds will turn yellow/rotten, dried and in cases fall off. When butterflies lay their eggs around the leaves, the newly hatched worms may also chew the leaves and buds.
Here is one example of a dried young bud:
In some another cases, spraying pesticide or fungicide directly on the buds too much may burn the young buds, especially in hot weather and thus making them fall off eventually. Could it also be a dried burnt spot by the sun? If, however, you notice that the buds keep getting black and fall off after very good care, chances are it may be the variety's health. The plant itself might be weak genetically, or weakened after many cloned generations (i.e. propagated by cuttings), or possibly by some chemicals some nurseries use.
In another case, the blackened rotted flowers may be affected by too much rainwater. This reason is only for your information–I don't think it applies to your case though:
But I hope this helps!
More info here: Adenium buds falling off: Why?
Why are my Seedlings' cotyldon yellowish
(Note: Cotyledons are the adenium plant's first two leaves, aka the seed leaves. The third, fourth, fifth leaves and so on are called true leaves)
--> Thanks for your question. To be honest, I am not really sure what might be the cause in your case. Could it be because it has been quite sunny? One or two of my seedlings have had the cotyledon yellowing as I remember. The cotyledon turn brown and dry afterwards but are still sticking onto the seedling bodies. I'll check tomorrow. Anyway, if your seedlings have grown more leaves and the other leaves are green, chances of survival will be high. Maybe you could move them somewhere with more shade. And check the little stems, if they feel firm and do not look too wrinkled, then they will be okay. I hope this gives you some clues!
The yellowing cotyledon seedlings I was talking about are here:
These guys have experienced some sun stress. But interestingly, only one of the cotyledons turns yellow and dry. The other true leaves are also quite yellowish. I am putting them in a cooler place.
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