What should I do if the leaves of an orchid turn black and wither from the base?

When an orchid seedling turns black and rots from the roots upward, it is soft rot. If you pull out the rotting seedling, you can smell a foul odor, a bit like over-fermented distillers' grains. The pot of Cymbidium goeringii (spring orchid) in the photo below developed soft rot in the first half of the year.

From the photo you can see that only one old pseudobulb is left; when it was potted up, there were two pseudobulbs. The other seedling had soft rot. Fortunately, I found it early, and after treating it with my own method, it has now produced a new seedling.

Now it seems that the other old pseudobulb is also unhealthy, but the new seedling is indeed doing quite well. Reblooming an orchid like this will still take time, but being able to personally bring a sick orchid back to life will, for orchid growers (especially beginners), bring about a qualitative leap in their orchid-growing experience.

That is the method I have described above. Orchid growers who are interested can give it a try. If you have any other questions, feel free to leave a comment in the comments section.