Citrus branch die back after blooming

[pombazaar]

Last year I had a Persian lime and Meyer lemon that were bought in the winter months. Eventually the Meyer lost all it's leaves until it was taken outside in April and it shot out some mad growth. The lime ended up getting infected with scale insects after it bloomed and ended up dying before it made it outside.

I ended up bringing the Meyer inside when lows started hitting around the 40s. The tree is moderately watered and kept by a window indoors. It put out well over 100 blooms, all of which fell off (which is normal for a 1 year tree). After all the blooms fell off, so did all the leaves...like all of them...over 100 green healthy leaves in maybe 3-4 weeks.

I'm thinking this has to do with shock..I probably brought it in a little too late. But now my Meyer is mirroring the Persian lime with branch die back. I've triple checked for scale insects and I don't see anything. Is branch die back normal for indoor citrus after a huge bloom? I'm worried I'm going to end up losing the entire tree if the branches don't start sending out new shoots.

[alanmercieca]

I have never had branch die back with my 'Improved Meyer', or with my 'Midknight Valencia', they are outside most of the year, they are brought in whenever it could hit 39 degrees or colder during the night, brought back out during that day. As far as I know all 'Meyer' trees died in the USA a long time ago due to disease. 'Improved Meyer' is a hybrid made by a university, using the original Meyer lemon, and some type of mandarin orange. It's very disease resistant. I have no idea what may be causing branch die back unless it's some sort of disease, or insects. Disease can be caused if a citrus is grafted on the wrong rootstock. Where did you get this tree?

[pombazaar]

@alanmercieca I just realized I never responded to this. All of my citrus have died since my OP. The tree in question was purchased at English Gardens. I suspect that it died due to a combo of things: extremely poor indoor lighting, lack of proper natural light from the sun, dry air, and cold room temps (68F). I was bummed because I had some really cool citrus that put out a lot of growth. I'm planning to setup a large greenhouse soon which should help to alleviate a lot of these issues.

How is your Improved Meyer lemon doing?

[alanmercieca]

It's never cropped well and it looses it's leaves a lot. I think that happens because it rains a lot, and gets very humid here. I think that much of the time the soil is too wet, I have even tried making homemade soil that drains better than the manufactured citrus soil. Still soil is too wet. Yet a part of me wonders if it might be a boron deficiency. Next year I will try and make extra sure that it does not have any deficiencies. I am also thinking of re-potting it, and putting gravel at the bottom, for even better drainage. I think it's several problems at once. The same thing is happening with our 'Midknight Valencia'.

I gave up a long time ago trying to keep citrus indoors during the winter. It's next to impossible to know how fast the heating will dry out the soil. I leave my citrus in the garage for the winter. It does way better in there.

[pombazaar]

How cold does your garage get at the peak of winter? I know a guy here who kept a Meyer Lemon in his garage over winter and it actually did pretty good. I'm not sure if he still has it or not.

What about lighting? I'm guessing your garage stays pretty dark. Does that not cause severe leaf drop on your citrus?

[alanmercieca]

It very rarely hits freezing in the garage, if so for a very short time, and that's only in the coldest part of the garage.

Here most of the time it does not stay freezing temperatures long, we can open up the garage and bring it out during the day, we keep it on a nice plant cart when it's in the garage. So it's easy to move around as long as we keep it on a paved surface, well a sloped paved surface not so easy.

Citrus looses it's leaves once a year no matter what you do.