I have about 12 papaya young trees, around 1 year old. I started them from seeds and moved them to large containers with a well-drained soil mixture. During the summer period, I had them out in the sun and they were growing fast, but as winter came I had to move them into the house where they have a good amount of light from the windows and heating. But now they are dying one by one. First, the leaves start to curl and face downward, though they are still green and aren't dry. Then the bark starts to lean down and eventually fall from the point where the bark meets the soil. I have attached photos. Please help: what's causing this? Is it a disease, rot, or the cold weather?
Certified GKH Gardening Expert
Since this started when you brought the plant indoors, the problem is probably related to the environmental conditions indoors and/or watering.
The pots they are in appear quite large compared to the size of the plants. This can cause the soil to remain wet at the bottom even when it's dry at the top and even with well-drained soil, because the plant can't use up all the water in the large pot for quite some time. Excess water could then damage the roots (root rot or lesser damage) and cause the drooping leaves and stems you see. Removing them from the pots, checking for wet soil at the bottom, allowing them to dry out a bit, then repotting in a smaller pot, would be the way to solve this.
Another possibility to check into is temperature fluctuations in the house. This could happen if they're near a heat source or a source of drafts, and could make your plants quite unhappy.