I wish I could give you some valuable advice about your ground cherries, but I have only grown them outdoors, where they self sowed successfully. A far as the Dollarama soil is concerned, I have used it in the last year to pot up seven hibiscus cuttings I rooted in water. Of the seven, five have survived and are thriving, so I don't think the soil is your problem. I think both of these plants need full sun, and you may have stressed the ground cherries even more by repotting. I have never grown Cuban oregano, so have no knowledge of its growing habits. Hope some other gardener can be more helpful.

Hi northerner_on. Thanks for your reply! That's interesting you haven't noticed any problems with their bags of soil. I posted on another forum and someone responded that he used it many years ago and whether the plant died or just didn't thrive, he was not impressed with it and hasn't bought soil from Dollarama since. I can see your point about stressing the plant further by transplanting. My intention was definetely not to stress it, but to see how it would react with more space for its roots to grow. The pot of ground cherries that wasn't transplanted looks pretty much like it did when it came home or a bit better (the one on the right here in link below). The one on the left in pic is dried up, collapsed, and dead. The surviving ground cherry pot is now in a more sunny window than in the picture btw. I would have put them outside but I don't even have a balcony. Sometimes I open the window for it to get unfiltered rays though.

Here is a link that might be useful: groundcherry

Regarding the Cuban oregano, when I got it from a greenhouse run by students they told me it would survive indoors during the winter. It looked like this originally: (see link). Right now it is just a brown stubby stem because the leaves started wilting and I cut them to root in water to try to save them. Was never transplanted into other soil/pot.

Here is a link that might be useful: cubanoregano

dollarama soil shouldn't be the problem. it's basically a soilless mix. not much nutrition added to it. Much of the other soilless mixes have slow release fertilizers added to them.

Anyway ground cherries and cuban oregano are both outdoor plants but in our cold climate they just won't survive outdoors in winter. if you have a good plant light, then there's a chance they will survive.

Lost of factors why plants will wilt right after planting - one is that it suffered transplant shock. A way to go around it is to make sure the plant is well watered hours before transplanting. Also to make sure roots are not damaged or disturbed during transplanting. Especially with ground cherries which are succulent like plants, they do need a good drink before transplanting. Also not a good idea to fertilize a newly planted plant. You risk damaging the roots. In anycase the roots having just been transplanted will need time to recover and cannot absorb water nor nutrients for the time being. Rule of thumb, the smaller the plant, the less transplant damage it will occur.

Leaves go yellow when they don't have enough nutrients. Tropical plants can actually go into a form of dormancy in winter- its a reaction to lesser daylight hours.

Some tropical plants can actually react to lesser lighting by shedding leaves or have branches dying. Like for example the ficus tree.

Also last, overwatering.. Too much water can make cells 'explode' wilt and then die. Cells are like balloons that do not know when it has absorbed too much water. So water carefully. Let it dry between watering.

Cuban oregano certainly resembles coleus, succulent tissues and they are okay under good amount of indirect sunlight. But greenhouse lights would be better. You can propagate more by taking branches, letting it dry in between and then sticking them into soilless mixes.