Apartment plants

Suffering Zamioculcas

Question: why is my zamioculcas suffering?

Good morning. I would like information on how to treat my "Zamioculcas". it is placed in the house, in a fairly bright room (since I have a window that I keep open during the day). I have owned it since July 2011, and I water it about once a week. I do not use pesticides or fertilizers, there is no insect presence. Initially it has increased a lot in volume, as many as 5 branches. Today, however, the plant has problems: the leaves have changed color and become red and fall. What should I do??? I hope you can help me.

The zamioculcas is an overall resistant plant that hardly gets sick and in general has a good degree of rusticity. Although it is a plant originating from areas with a warm climate, which therefore needs high temperatures to grow and develop optimally, it is a plant that also grows well in apartments.
One of the factors that can negatively influence the growth of zamioculcas and that can compromise health are the wrong irrigations or an excessive amount of water compared to the real needs of the plant. Excessive soil moisture can cause a series of plant problems that can lead to decay. The yellowing of the leaves and their fall are very often caused by an excess of watering which leads to the onset of root rot.
The problems due to parasitic attacks, frequent in other types of houseplants, such as aphids and cochineal, do not occur frequently in zamioculcas plants. The only species of cochineal that manages to create some small problems with these plants is the cochineal with scudetto which can ruin the leaves of the cochineal causing dark spots on the branches and leaves that parasitize.