Citrus not thriving

[Beano]

Are citrus deciduous? I have one with quite a nice trunk but it has suffered since I got it last year with bugs eating it, possum eating it and possum spray burning it. It's still green under the bark but it just won't leaf out anymore. Do they go bare in a Brisbane winter? I have no idea what kind of citrus it is.

[shibui]

There are some semi deciduous citrus. Poncirus trifoliata turns yellow during cold weather here but shoots again in spring. I would not expect them to loose leaves in Brisbane though I did note that it got down to a frigid 7C up there earlier this week. Same overnight temp as Canberra
Most citrus do not grow much, if at all, during cooler weather. I'd guess that yours cannot shoot at the moment so will have to go a bit longer without leaves but should make new buds when the weather warms up

[Guy]

make sure your mix is free draining---put it in water until it stops bubbling---use a water spray to make sure there are no resident bugs on the tree--place in your warmest spot until spring--no fert till shoots are advanced

[Graeme]

I have a trifoliata up here in Hervey Bay that I was thinking about throwing out because it wouldn't do anything and hasn't for a couple of months now. I've had the plant for three years and this is the first year it has sulked like it has. Anyhow I watered yesterday morning (only do it every second day) and the damn thing is covered in tiny new shoots. I also have a Kumquat and a couple of bush lemons that look the same, covered in yellow leaves and simply doing nothing. Noticed this morning that they appear to be waking up as well. My advice (for what it's worth) is to just hang on a little while longer and I reckon you might start to see some movement soon.

[treeman]

Citrus are quite difficult to grow in pots long term and to keep looking good. They need a high fertilizer rate to keep leaves green but to achieve this they need a very well drained acidic medium. pH should be in the 5 to 5.5 range if possible.
Using fertilizers with urea and/or ammonium would help with this. They can suffer from magnesium, iron, zinc and manganese deficiencies. Either one or all. All these trace metals become more availanle with acid media so this is the most important starting point. But even so it is hard to keep a good leaf colour when temps get low. I have a HongKong kumquat seedling (1 left-started with 10!) which kept a dark green colour all winter outside this year. Temps got down to 5C on a regular basis! Why did it stay dark green....no idea.

[Beano]

It's dead. Thanks for the advice. Slowly lost its green further and further down the trunk. Shame, it was a nice trunk.