I have a problem with my citrus sapling. This one is about two years old (!?!?) and I planted it myself from a seed out of an ordinary lemon or orange (can't remember which :p ).

During the winter months I kept it inside and it continued to do well. However when the weather turned for the better and I put it outside for it to enjoy the full sun it went downhill (I still brought it indoors every evening).
Over the course of a few weeks all the leaves turned grey/whitish and growth seized. It didn't have this problem when I put it outside the first summer.
This started a few months ago, but I didn't want to give it up so quickly so I left it outside still.
However today to my great surprise I noticed the growing tip beginning to form new leaves again. And weird: at the base of the petioles more down the stem there are new stems forming. I didn't know a tree plant this young was capable of doing that!?

Any explanations?

It looks like the leaves were sun burned. Plants that have spent several months indoors generally can't tolerate very much direct sunlight. They need to initially be exposed to the sun for short periods of time until they get used to it.

a gradual transition to the full sun would be good. Maybe put it in a filtered shade spot for a few days then ease it back into the sun.

Also, what fertilizer has it had? There is a specific citrus formula sold here with high proportions of certain micro nutrients. Sorry I am not at home right now so can't list them for you.

Isn't sun burning turning the leaves brown instead of white?

And I mulched it with some compost, use an all purpose liquid feed and once used a nitrogen rich fert from fermenting nettle leaves. But this was all after the leaves turned.

It looks to me as if it is recovering nicely now. I would just give it some time to see how it does before changing anything else.

Arico said:Isn't sun burning turning the leaves brown instead of white?

Nope, they usually turn white, almost looks like they've been bleached.