Help! Dying dieffenbachia/Dumb Cane

[Nbardelli]

I’ve had my dieffenbachia for about 2 years now. It was always so happy until about 2 months ago when I noticed the leaves were more pale green vs. rich, dark green. I moved it a little further from the window which seemed to help (new growth looked happy and dark green). Suddenly the leaves were getting crispy, so I increased watering slightly, but it is still struggling.
I live in a place with very hard water. I do leave it out for 24 hours before watering but think this may not be enough. I also found these small black spots under 1-2 leaves - residue from bugs maybe?! Any help is appreciated!

 

[Marck]

Greetings, welcome to the Forums.

Those black spots are Thrips (Thysanoptera). First wipe the leaves with warm water, but you will also likely need to use an insecticidal soap spray.

Also check the drainage on the pot. Soil should be damp, not saturated and it should be allowed to partly dry before the next irrigation.

For Dieffenbachia cultivars bright indirect light is ideal. Also if you do not fertilize your houseplants, begin to do so. Monthly during the growing season as you irrigate is an easy way to incorporate this into tour routine.

When the weather is warm, perhaps now in San Diego, consider setting your plants outside whenever possible. Many houseplants benefit from outdoor 'vacations', where airflow and relative humidity is greater.

 

[Nbardelli]

Greetings, welcome to the Forums.

Those black spots are Thrips (Thysanoptera). First wipe the leaves with warm water, but you will also likely need to use an insecticidal soap spray.

Also check the drainage on the pot. Soil should be damp, not saturated and it should be allowed to partly dry before the next irrigation.

For Dieffenbachia cultivars bright indirect light is ideal. Also if you do not fertilize your houseplants, begin to do so. Monthly during the growing season as you irrigate is an easy way to incorporate this into tour routine.

When the weather is warm, perhaps now in San Diego, consider setting your plants outside whenever possible. Many houseplants benefit from outdoor 'vacations', where airflow and relative humidity is greater.

Thank you so much! It seems to be doing better. Do you have a type of fertilizer you recommend for indoor plants?

 

[Marck]

Any complete, general-purprose liquid fertilizer should do fine. Miracle-gro is the standard, but there are other fine brands as well.