I have several indoor plants for two years. They were all in very good
conditions. However, two or three months ago, some leaves of almost
all the plants are starting to wither. The most serious one is Jasmine
-- Right after the new leaves grew out, they withered before even
turning yellow. The other plants with similar problems a
Philodendron, African Violet (more than half of the leaves are
withered), Anthurium and Peace Lily. Anyone can help me with this?

Thanks a lot!

Ren