I started to see the end of my dracaena's leafs becoming burned, then later the other leafs started to became brown-ish. See the photo below.
I put some organic fertiliser and later left it outside, where it got some light rain and sun for 2 days. Temperature was around 10°C.
Today, I saw its condition has became worse, so I put it in my house again, but now I don't know what to do.
What to do next to save it?
Brown on the inside of the leaf can mean sunscald, too much light all at once. Indirect light is recommended. The leaves may or may not survive, remove dead parts when they look finished and recall that with less leaf area transpiring it will not need as much water.
10 deg C is chilly for this plant. Wait until 20 C to put it outside and then only in a shady spot.
Blackening on leaf tips (I see that many lower leaves have been trimmed back) and edges indicates salts in your irrigation water. Find out what is in your tap water (fluoride can be damaging) and if possible use rain water or melted snow.
