Hi,

Dieffenbachia Turning Yellow

Your plant is called a dieffenbachia. The bottom leaves on a dieffenbachia plant can turn yellow for a number of reasons: the plant is near a cold draft or an air conditioning vent. The bottom leaves are not getting enough light. The soil has gotten too dry. The plant is over watered and is dying.

Your plants looks like it is an over- watering issue. It looks like you moved it to a pot that is too large. When a pot is too large, the soil does not have a chance to dry out quickly. The roots stay wet too long and begin to rot; this causes the plant to eventually die. Your plant container should only be 1″-2″ wider and 1″-2″ deeper than the root ball of the plant. There must be drip holes in the bottom of the pot to allow excess water to drain out. You need to take the plant out of its pot, get rid of all the wet soil, remove all of the dead or dying leaves, and allow the plant to lay out, bare rooted for 24 hours.  Hopefully the roots will dry out. Re-pot into the proper size container and don’t water for at least 7-10 days.  When you water, water well and then allow the top 2″-3″ of soil to dry out before watering again (usually takes a week or more).

You can read all of my care tips for a dieffenbachia in the Popular Houseplant section of the website. The picture is of a different variety, but the care is the same.

https://www.houseplant411.com/houseplant/dieffenbachia-how-to-grow-care

These plants are considered very poisonous and should be kept away from pets and children. Read more about common houseplants that are poisonous in my book  Don’t Feed Me To Your Cat! A Guide to Poisonous Houseplants