Soil too moist? How strong of fertilizer? Could be fertilizer burns i.e. too much salt. Cold temps triggered dormancy? My guess is likely just weather triggered dormancy.

Are the caudexes and branches still firm, no squishyness? Any discolouration on them? Regarding the neem oil, did the problems arise after the treatment? Have read that some do get probs after neem oil application. Hopefully those who use it will see this as I'm not at all familiar with it or its use. Were they all treated as they all appear to look the same? Did you fertilise during the winter as well, guess not, but just asking in hope that we can find an answer for you:-)

I would risk unpotting the worst looking one to see if anything is amiss underground, must be worth checking out, if only for peace of mind that all is ok down there.

Gill

Carol, It could be the Neem oil treatment, but I have not had any ill effects w it's use. The strength used and/or where the plants where placed (i.e. Sun) could cause similar effects.

My first thought was Soil, Watering/Fertilizer. With seeing all of them looking pretty much the same, would make me think the issue is related w all the plants. They do not need to be in blazing sun all day.

Definitely worth a check of one of the plants roots, as Gill mentions. Peace of mind. If the soil and drainage is quick and does not retain water at the bottom of the pots, this is good. If there is a lot of finer particles from the soil sitting at the bottom of each pot, this will cause a perched water area. Area where the water sits and stays too moist.

Also, once you check things out. If not too wet and roots fine. I would be watering w straight water when needed for a bit to get them coming back.

Rick

Well that's good news isn't it! I would pot back up again and maybe keep indoors or somewhere warm and kick start them into growth mode.

Has this one dropped its leaves or have you removed them yourself? I would be very tempted to remove the worst leaves, realise others may shriek in horror at the suggestion though, as I don't think the plants are drawing anything from them....the ones on the foreground plants especially so. They certainly won't revert to green anyway. Maybe snip them off close to the petioles as if you pull the whole leaf away petiole/stalk and all, you may risk tearing the skin. Remaining stubs will then fall off on their own and you can always dab the cut surface with a tissue if it leaks any sap. They should soon regrow fresh leaves.

You can always wait and see what others think first though.......

Gill

I think everyone else has covered everything I can think of already. The only other thing I could add is watching out for root mealies because leaves yellowing like that is the most obvious symptom. You can do an internet search on what they look like as they are really easy to miss if you have perlite in your mix. Tiny white crusty looking specs on the roots and in the media. But it's probably not that.

Oh wow! To of mine had what looked like root mealies. One looked like it had clusters of tiny yellowy did on the roots. I washed it off thinking that it was just a weird fungus and repotted with all of the other guys. I'll be drenching them in neem oil when the soil dries, I guess.

Neem oil won't do much good because of the waxy coating the bugs make. /If/ it is root mealies, I'd wash the roots very well and give it a brief soak in a malathion solution, or 10% bleach for 15 minutes. Then pot up in either entirely new pots and location, or sterilize your old pots if you want to reuse them. Add systematic insecticide granules like Hi-Yield (something using imidacloprid in it) and that should do it, but it would be a very good idea to recheck them once a month for a while to be sure you got rid of them. Repeat as necessary and keep them isolated away from other plants.

Depending on what Neem oil you used that could be the problem. Straight neem oil here in Australia burns the leaves when the sun hits the plants. We also have Econeem which is much more gentle and doesn't harm the plant.

Christine