Whitish Discoloration on Leaves (Indoor and Outdoor Plants)

[Cenia Correa]

Hi, I am new to this forum. I hope to share information and gain knowledge on keeping my plants.
I have many plants inside and outside of the home. Some are doing well. I have lost a few succulents recently. I have a few plants that have whitish, discolored leaves. Could this be a fungus? Could it be what is making some plants not do well? How should I treat this? It doesn't rub off, it is a discoloration of the leaf. Even with this discoloration the palm has new fronds. The colocassia and orchid are outside on the porch with other plants. The palm, pencil cactus cutting and jade plantlet are indoors. The pencil cactus & jade seem to be stunted, they have not had any growth in months.

 

[Rajesh Sethi]

Mildew

spray anti fungal solution

Provide ventilation to lower humidity, add fertilizer to allow plant to grow fast, separate each plant(so, no two plant rub against each other)

If the plant is easily available, then replace it.

 

[Larisa]

Just in case, it would be nice to take a large magnifying glass and inspect the leaves to see if there are parasites. For example, a spider mite.
Orchids like to dive a gosh in warm water for 30 minutes once a week.