What is happening to my Dieffenbachia, and what can I do about it?

Question

BACKGROUND

I brought 2 similar plants, of this same Dieffenbachia (see attached photo):

• Both were brought from the same nursery
• Both were brought at the same time
• Both were placed in new (never been used before) plastic pots
• Both were put in the same fresh (never been used before) potting mix
• Both were put in the same room with similar light and water conditions

I've had them for about 10 days now. I've had Dieffenbachias before and I also currently grow other Aroideae plants (Aglaonema, Alocasia, and Philodendron) - all exhibit yellowing of older (or more accurately I'd say lower) leaves, as a part of it's natural growing process.

ISSUE

This time the leaves are yellowing very fast

All yellow leaves in the photo have yellowed in only a few days - usually on other plants I see one leave at a time proportionate to its growing rate

Also - the other plant is, of course, healthy :)

Leaves aren't yellowing regularly

It looks like some kind of fungus or bacteria, as evident by the edges of yellowing leaves

IDEAS?

I thought about treating the soil with hydrogen peroxide, but I don't want to "kill" the soil - it's a fresh potting mix.

What do you think?

Answer 1

It's not a disease. It's most likely a issue of stresss. It could be the difference in growing condition from your house and the garden centre. It may have been at the garden centre for a matter of a few days. or even a few hours. Depending on where the garden centre got the plant it may have been on a truck in complete dark for days trucked across the country. I worked at a garden centre for many years. It was not uncommon to see this kind of response from plants after long days of being trucked. I've seen plants shipped for over a week in complete darkness, packed in very tight with little air flow. This was the most common for tropical plants. In a matter of a few days the plants start to lose some of their leaves from the stress of lack of light. But, it rarely effects much of the plant only a few of the leaves. Maybe half at most. It's amazing how long plants can live in those conditions and still come out in pretty good shape. Other than the yellow leaves the rest of the plant looks healthy. I would be careful not to expose it to too much light, but other than that all you can do is treat like you would if they were not showing yellow leaves. You can always call the garden centre and enquire about it's recent history.