Hi,

I live in Switzerland, have recently brought my lemon tree indoors. Have the pot wrapped in Christmas lights which I use over night, and sat in a tray of water, with the pot on legs so the pot doesn't touch the water. The soil temperature is between 70F and 75F (warmer over night), I don't want to leave the lights on while I'm out of the house. Pics below:

http://upmyphoto.com/image/24998/f59205e
http://upmyphoto.com/image/24994/3331285
http://upmyphoto.com/image/24997/0678f87
http://upmyphoto.com/image/25003/e6870c2
http://upmyphoto.com/image/25002/a353379

It continues to drop leaves, about 3-4 a day and refuses to grow. It's currently having a massive flush of flowers and lemons, but all summer long since I have had the plant it hasn't grown a single leaf. The new growth of stem and leaves gets to about 5-10mm then goes black and dies. Investigating, I see a few strange white spots on some of the leaves, shown in the below:

http://upmyphoto.com/image/24996/6656b97

Also, some of the leaves have a very small white something. I don't see them moving, so don't think they are insects, maybe eggs. I sprayed well before I moved inside, so am surprised. I also flushed the container last weekend. Eggs tried to be shown below:

http://upmyphoto.com/image/25000/d7471d1
http://upmyphoto.com/image/24999/2a36f68
http://upmyphoto.com/image/24995/0f0c8c5
http://upmyphoto.com/image/25001/25613d9

Your help is as always really appreciated.

Picture 24998/f59205e: are you sure your Christmas lights are of the bulb type, not the LED type?

Picture 24994/3331285: magnesium deficiency on old leaves, nothing to worry about..

Picture 24997/0678f87: sunburn.

Picture 24996/6656b97: dust that have dried of water drops, but on the bottom right leave you maybe have eggs of white flies.

For the last pictures, I don't know. Could be spider mites traces. We all had spider mites in Europe this summer, too warm and too dry.

Hi there,

yes, they are bulbs, and do the job in terms on warming the soil up I think. That's a decent temperature isn't it?

"Picture 24994/3331285: magnesium deficiency on old leaves, nothing to worry about.. " these are actually fairly newe leaves, about 1 year old.

Possible white flies and spider mites, what's the best treatment?

Anyone have any idea why the new growth fails to grow further?

Another 5 leaves dropped overnight

They're not old leaves, a mixture of old and new. I kept the lights on 24/7 now, soil is up to 77F. Have sprayed a lot with soapy water to get rid of any possible spider mites.

I have blinds on the outside of the kitchen windows, shall I use them and reduce the direct sun light?

Help is appreciated.

beno there is a guy in Switzerland named Alexander Schmid who is a master at growing container citrus. Try looking him up, he is a very nice guy.

Hi Laaz, thanks for your reply. I googled him but couldn't find him, any chance you could point me in the right direction?

Cheers

Hi guys, unfortunately no reply from the recommended chap.

Both my citrus seem to be loosing lots of leaves so it must be something I am doing wrong.

Here are the conditions:

Air temp - 65 - 70F
Soil temp - 77F
Located east facing window
Window left open - outside temperatures roughly 40 - 65F

The bugs seem to have disappeared, I sprayed about 5/6 times with water and a small amount of washing up liquid.

Any suggestions of what to try? I could raise the soil temp further or move the plant out of the sun light?

Cheers

>>> The new growth of stem and leaves gets to about 5-10mm then goes black and dies.

Are these new trees or in new spots (i.e. has anything changed in the last several months?) If you've had these trees for years, in the exact same location, and thus have experience with their watering and nutritional needs, and nothing else has changed, I'd be at a loss from here...


If you purchased these trees before summer and have recently brought them indoors, cases like these are almost always due to over-watering. Can you explain how often you watered when outdoors and when you water indoors?

I am not an expert but I have seen the same thing occur on some of my trees occasionally so I will give you my best guesses and you can take them for what they're worth considering my lack of expertise. The leaves that are dropping look like good healthy leaves. I would guess they are falling due to a lack of water at the leaf during certain times of the day. All of the leaves are falling without the petioles which is a further indication of water stress. I have seen healthy leaves like these drop when the leaf temperature rises too rapidly. The leaf temperature rises faster than the rest of the tree can supply the increased amount of water required by the leaf because of transpiration. I have also seen new growth die and turn black for the same reason just like you described.

The solution is to increase water arriving at the leaf or decrease transpiration. Raising the root zone temperature has been the most effective way for me to increase water arriving at the leaf although I have never had to raise the temperature above 75F/24C. You are already at that temperature. In addition to wrapping lights around the pot, I have also wrapped the tree trunk with lights on one of my trees (a satsuma). I do not know if that was helpful or not but I do know that the tree immediately produced a large growth flush after not producing any new leaves for a year and a half. I have not found increasing humidity by using a water tray to be effective in reducing leaf transpiration. Reducing sunlight by using a shade cloth or by moving the tree further from the light does seem to be effective in reducing rapid leaf temperture rise and transpiration. Another possibility is to use a fan blowing lightly on the tree to reduce rapid leaf temperature rise and transpiration though I have not tried that method.

If this is a new tree there may be another possibility. When I received my orange tree as a bare root tree I noticed it had a very small root ball in comparison to the leaf canopy. It dropped many leaves and didn't grow any new leaves for nearly a year until the root system and leaf canopy bacame more balanced by a combination of new root growth and fallen leaves. The leaves that fell were healthy but there wasn't enough water arriving at the leaves.

I think I will head to the garden centre tomorrow.

This tree looks doomed to death, I will try to get some better soil for it. I have never seen CHC in Switzerland before so maybe Orchid soil with some peat will do. I will have a look at the roots and see how they look. If they dont look good I will trim them back and repot.

I will then continue to heat the roots, and keep the plant in the shade for another week or two.

Fingers crossed!!!!!!!!!!

I have used orchid soil mix before when I could not find CHC. And my citrus did just fine. Just make sure that it is not all large chunks or all small fine pieces. A good mix of sizes and you "should" be fine

So, it's now 100% clear to me now what the problem was. I bought some orchid soil yesterday and went about repotting my tree today.

I nearly broke my back lifting the tree out of the pot, it weighed a tonne!! Considering it's been 2 weeks since I flushed the container, it was still sopping wet!! The soil looked to be mostly dense compost with a few clay chunks just for good measure.

The roots were in bad shape also, I have pulled off as much of the old soil, unfortunately along with most of the damaged roots also and repotted with the orchid soil (which had mainly small chunks of bark). I added a load more holes in the bottom of the pot also, to add to the drainage. The pot is now half full unfortunately, as I have lost a fair bit of roots.

My questions now:

1. Where shall I put my tree while it recovers? I think maybe inthe hallway, no direct sun, fairly warm.
2. Shall I keep the Christmas lights on, to about 60/70 or 80F?
3. Shall I water it now. Most of the soil I added was dry.

Thanks again!!

Yeah over-watering is probably the most common difficulty when bringing it from outdoors to indoors. Once you get past that, there are lots of other challenges, but that's usually the first!

I'm not an indoors citrus guy, but what caught my eye was you stating the current soil was dry. Yes you need to water now! The dryness of the bark will hurt the roots. Normally with outside trees you soak Orchid mixes (any heavily bark based mix) so the bark is saturated, not hydrophobic, because it repels water once completely dry. But if this is straight out of a new bag, it's possible there is still a decent amount of moisture (supposedly our hands can't feel moisture in soil lower than 30 or 40% and roots can use moisture much lower). But yeah, I'd water it well right now.

Yeah, keep the soil temps in a good range and yes it still needs to have sunlight. You are correct, excessive hot, direct sunlight, will cause even more leaf drop as the current (lesser) roots can't support it. But you need to give it sunlight so it can remain healthy and start rebuilding roots. If you have SuperThrive, I would give it some to help rebuild after the trauma (the only time I recommend it). If you have a good Micronutrient blend (no Nitrogen) then I'd also use that. You don't want to fertilize heavily right now, but some is good, esp. with low nitrogen.

Have any pics?