Could be too hot and not enough water. Try a little shade.

The other common cause of this malady is frost burn; it is exactly the same injury physiologically, only from extreme cold versus extreme heat.

This post was edited by Johnmerr on Fri, Jun 14, 13 at 15:10

Sorry, I should mention that my plant is indoors. When I bought it they had it outdoors. Now it is under a HO fluorescent fixture and receiving 10,000-20,000 lux. Temperature is about 75F.

The plant was also watered a few times since this started happening and it keeps getting worse with more new growth dying.

Pictures??? Maybe it is being burned by the light, if it is too close.

This is a problem with the "new growth" or terminal and lateral buds, but is not isolated to just the portion of the plant closest to the light (which is why I don't believe light to be the issue). The buds grow maybe 1/4'' before turning black, drying out, and falling off.

Picture:

{{gwi:591123}}

anyone?

Probably environmental, in part from moving an outdoor plant indoors. Potentially aggravated by too much or too little light and/or water.

It might help us if you post a picture of the entire plant.

It looks like lack of humidity to me. Being under those lights indoors the humidity levels are probably pretty low. I would try misting your plants. :-)

More pictures

{{gwi:591124}}

{{gwi:591125}}

{{gwi:591127}}

in the picture it looks like you have iron/manganese deficiency.
the leaves in the lower picture shows green veins. healthy leave should be all green.
what fertilizer do you use?

Now that you mention it that part of the plant does appear to have chlorosis between the stems pointing to the deficiencies you described. It's weird that only that portion of the plant appears this way while the other side looks perfectly green and fine, isn't it?

The soil I transplanted into is FoxFarm Ocean Forest which is a nutritious organic mix. I also added some FoxFarm dry nutrients which is also organic, but takes awhile for bacteria to convert into usable plant food. The soil is a complete soil though and the bag says it should provide both immediate and long term nutrients. It contains bat guano, composted forest humus, peat moss, oyster shells, kelp meal, bone meal, sandy loam, granite dust, fish emulsion, shrimp meal, and Norwegian kelp meal.

Whether or not any of those ingredients have immediately available iron/manganese I don't know. I think that bat guano does though...

Thanks for your knowledgeable response, Josh.

- "Are you monitoring the moisture levels with a wooden skewer stuck all the way into the container? That's the first thing I'd ascertain...moisture levels, and interval required for the mix to dry. ."

Interesting concept! Never thought of using a wooden skewer to monitor moisture : )

Would you let the soil dry out completely in between waterings, or should i keep it slightly moist?

Thanks

Hey!
I wouldn't let it go completely dry because the mix will be difficult to moisten at that point. When the lower layer of mix is almost dry, I would then water. But first, find out when that will be. If the mix is staying wet longer than a week, I'd start making a new mix.

Josh

The same happened with my lemon tree. New growth, leaves and buds are more black... Did you figure out what have happened?

What Josh said and I would think it to be Thrip damage since that is what happened to mine at the time. Also, the leaves should look smoth and a nice rich green..A nice soilless mix should do wonders along with pest inspection, even with a magnifying glass..

Thank you! Hope after I report the tree will still have a new growth this season :)

Hi all, I wondered if anyone really got to the bottom of this problem? I have what I believe is a Eureka which lost all of its leaves 4 months ago. We are unsure of the initial problem, uncertainly diagnosing spider mites. However now, the new growth from the tree is turning black at the tips and then fallings off at about 1cm 1/4inch.

We repotted with perlite a while ago to make sure we didn't get root rot. We fertilize with a summer citrus fertiliser once every 2 weeks and used a natural compost for re-potting. We have used insecticide, washing up liquid, and hosed the citrus down to deal with pests. Also fun detective query - we had 1 lemon left on the tree which one evening disappeared. Who knows how?

I have a question for my potted lemon tree in balcony. Does not high infestation of spider mites cause leaf chlorosis ( lots of small light green spots on the leaf) and some time later most of the leaf will turn light green. Another sign is like some kind of rusty bottom sides of the leaves, also the tree has some of the new growth leaves deformed. And the major problem is that during the time it had lost half of it's leaves and few fruits it had, even some dark green leaves had fallen. I dont think spider mites is the cause of all this because i constantly keep their population at least at minimum. (Besides i had planted some marigolds around the tree and one of them ended up being consumed leaf by leaf until she looked totally browned)