Help/advice needed: Sick lemon tree

Hi everybody.

I am new to the forum, I have just joined as I seek help for my (possibly) dying floral buddy.
Namely a lemon I have got as a present from a friend, as a little seedling, has not been doing lately, and I have thought I might seek advice in forums like this that gather many experienced minds.

As you can see on the images attached most of the leaves fell off, and before they did they turned yellow and dried out on the outside.
It has been undergoing leaf shedding before (sometimes if someone else would take care in my absence and would not water properly, sometimes with no apparent reason), and leaves they would often turn yellow and sometimes drop completely but then regrow again soon after.

I have also found small yellow dots on the leaves (and some spider web like threads) and used pesticides assuming it is some kind of vermin, but it didn't seem to help.
Recently I also read that it might be a funghi that often attacks lemon and is treated with copper based fungicide.

I couldn't get my hands on copper based but got some "universal" fungicide from Amazon, but now only thing that happened is that leaves dried out and fell off.
I am not sure if this is related with the treatment (perhaps I applied too much), with the infestation itself or some completely other factors.

As I said, these yellow dots have been around for a long while but lemon seemed be able to live with them and treatment didn't seem to help.

I have also noticed that last weeks soil stays moist much longer, typically it is dry after only 3-4 days (its very sunny in our apartment) but now after last watering the soil remains wet since nearly a week.
I am no expert in the field but somehow I reckon if plant is ill and not growing that it must absorb less water from the soil. I am also afraid if this can lead to root rot?

For some reason, of all the plants I have in my apartment I have been strangely, emotionally attached to this particular one and I would hate to see it go.
Therefor would be grateful for any advice what to do.

 

First thing to say is, Lemon plants dont make great house plants, they need bright sunlight for a good few hours a day, even in winter, if they are to grow really well.

Do those whitish spots rub off?
It does look like there is some kind of pest/ fungal problem.

Has the pot got drainage holes, it doesn't look like it.

I'm thinking more than one problem, more a collection of problems that are adding up to what is going on.

 

Citrus don't like heated rooms, and often drop their leaves over winter, but that tree has citrus snow scale. Those little white dots are minute scale insects that suck the sap. It's normal that the tree isn't taking up moisture...it's got hardly any leaves. First of all, knock it out of it's pot and see whether it's got any healthy roots. If so, re-pot into slightly acid, well-draining compost. I think there's a specific one for citrus and mediterranean plants. Then I'd take off the remaining leaves, or wipe them thoroughly, and check the stems (especially the leaf axils) for 'dots'..rub or wipe them off . As there's no chance of it fruiting this year, you could use a systemic insecticide, watered in, but try not to leave it in sodden compost. Then as pete says, it needs good light in a cool but frost-free position.

 

Thank you both for your replies.

I always though this is a number of issues rather then a single one, tho one of them might be a dominant problem now.

Regarding the spots - they do not seem to rub off. To me they seem as if they are "embedded" in the leaf, and they are rather yellow then white. But again they are tiny and its hard to say.

Pot doesn't have drainage and I have just realized what a problem that is. Old pot in which I last re-potted it last had a drainage hole, but my wife last re-potted it into the this new pot without the hole. I have A LOT of gardening soil that my wife bought for reporting the plants, do you think that should do for now as a first aid or does it make a big difference in which soil I re-pot it?

What would be an appropriate treatment if I find during re-potting that roots seem to have started rotting? I guess there aint much that can be done then. (not sure if it makes sense to apply fungicid?)

I also currently apply something against pests (it says to be universal against mites, scales etc) and I use it more regularly and consistently then I did in the past, where I thought treatment doesn't have to be too frequent.

I guess light-wise it is still good, our apartment is as sunny as it gets in Berlin, and right now temperature is quite optimal. I always turned off the heater near to it as I was afraid it might make the air too dry. In summers however, our apartment get notoriously hot (again for north european standards) so I might need to think of a better place for it, tho it seemed to enjoy it there until now and grow like crazy in the summers.

Thank you again for your advices, I am quite new in taking care of plants and I keep finding out how many wrong habits I had, but I guess its all part of a learning curve I really want to save this one tho as it was a gift from a friend who is not around anymore.

 

Hi again, definitely check roots. They've probably drowned, but if there are signs of life, any rich, well-drained compost will do at a pinch. It'll need minimal watering! If what you've got is not for ericaceous plants, it'll just mean giving the plant a dose of ericaceous fertiliser and/or sequestrene from time to time, once it's growing well again. You're right...fungicide won't help.
I stand by the scale diagnosis..it's unmistakeable. It is difficult to dislodge them. I use a stiff brush on older, tough leaves and stems. You need to check the undersides of the leaves also, for what looks like white powder. That's the 'youngster' stage. They even infest the fruit, but as that's not a problem for you this year, I suggested a Systemic insecticide. If such a thing is still available! Forget the 'organic', ready-to-use contact insecticides....they don't even begin to touch scale, and the predatory insects like flies, wasps, hoverflies etc. don't have access to clean them up.

 

I trust you ofcourse on your diagnosis, you are the expert here
I used something that contains main active substance Pyrethrine, but now looking at it seems to be organic insecticide, hence probably as you suggested not enough.

I will run down to the nearest gardening store and ask them to suggest something to go nuclear on these little illegitimate children. (if I manage to explain this well in my still level 1.5 German)

I've read somewhere that using root growth hormones can help with recovery, is that true?

 

I'm no expert, apasagic, but after years of killing off various citrus plants, I've just about got them sussed now Scale is definitely the worst problem as, normally, the last thing you want to do is introduce a chemical into the sap and the fruit that will be consumed. In this case, though, by the time the plant's in a fit state to fruit, the chemical and the pests will be long gone.
Good luck with the German! French is easier
These are some of my citrus trees....

 

I am coming back again with some questions on the topic.
Namely, I have repotted the plant in a bigger pot with drainage holes and used appropriate citrus/cactus soil, I gave some root activators (since I read they can help plant recovery) and I have applied some systemic insecticide (acetamiprid). I also removed all the leaves and branches that seemed most infected. Plant started to recover quite nicely at first, as you can see on the photos, new leaves started to sprout from everywhere, but at some point they started to brown and dry out until almost all of them died and dropped off.
The whole process repeated itself one more time and there is few of these young leaves left but they also don't seem to be doing super well.



I water the plant when the soil gets dry a bit under the surface, approximately once a week or so. I sprinkle it with water daily.

I started to wonder if I applied insecticide incorrectly (perhaps too much of it) so I didnt apply more of it. I thought the same for the fertlizier (also it is new soil, so I guess it shouldnt lack nutrients), so avoided using it last two weeks.

Any idea what could this about and what could possibly help?
The plant is on the window so it receives as much sun as there is these days.

 

Are those new shoots dying?
Cant work out, from the pictures it looks to be shooting ok.

 

Yes sorry, pictures are awful. I try to take better and more recent ones.

But yes, they mostly all died out meanwhile and dropped off.
You can perhaps see on this zoom in what I mean by "dried out". (this was half way thru the process)

 

I've got a nasty feeling its died.
The shoots were probably just the sap rising, but if the roots are not working they shrivel and die.

 

I think the roots will have rotted. Unless there's a lot of top-growth to support, they can't stand being constantly wet, or even too damp. It's a mistake that I've made so often in the past I'm sorry that all your efforts have had so little result, apasagic. But now you know the secret to growing citrus well. Good drainage and only water when there are lots of leaves to absorb it.

 

I am afraid that might be the case. They looked fine when I repotted the plant and tried not to overwater but perhaps I still did. I will check for remaining scales and remove by hand if I can and then just leave it be, be patient and see what heppens. Dont think more insecticide would be a good idea in any case.

 

Also, this is a very impressive lemon tree!

 

Goes with the lime, orange, mandarin, satsuma, kaffir lime, caviar limes....once I'd cracked it I got a bit carried away