I have very little experience with houseplants. I recently purchased a Calatheas and since I brought it home it has been going downhill. The leaves seem to be systematically browning around the edges and then the entire leaf withers and dies. About three of the leaves have died completely and I have had to chop them off. Any suggestions from someone with more experience? It is such a beautiful plant, I would hate to kill it.
They are pretty thirsty plants, and come from a very humid area. Try deep soaking the plant to be sure there are no dry pockets in the soil.
I grew a really nice one of these several years ago on top of an aquarium. Aquarium water was pumped up into a trough and irrigated the Calathea, Philodendron and several other plants.
The plant is VERY sensitive to chill injury, and prefers temps in the 70-85* range, so chill injury should be eliminated as a possibility. If your soil doesn't drain well (holds too much water), saturating the soil might exacerbate the problem - problem is, saturating the soil so 15-20% of the total volume of water applied exits the pot is the RIGHT way to water, so your soil might be inappropriately water-retentive. If you can't water correctly w/o having to worry about impaired root function, the soil is inappropriate - at least from the plant's POV.
The plant is sensitive to fluoride, and exposure is accumulative, so the older a leaf is, the more likely it is to be affected by the chemical. It's also extra sensitive to high fertility and to the nutrients K and Mn.
If I was growing this plant, I would be sure that
A) The soil is appropriate and allows me to water correctly w/o being concerned about impaired root function or root rot. (If the roots can't function efficiently, they can't move water to distal plant parts, so leaf tips and margins die.)
B) I can keep the plant warm enough.
C) I water with water that is free from fluoride or better - deionized. That means distilled water, rain water or water from snowmelt, water from air conditioner or dehumidifier discharge, or water from a Reverse Osmosis (R/O) filtering system. I have a small R/O system I bought for about $200 that I use to make all my drinking water and the water I use on houseplants. It was well worth the price.
D) That I use an appropriate fertilizer regularly at low doses.
Al
Calatheas require high humidity as well. I keep several in large terrariums (70-80% humidity) and they do fine, but I have never been able to keep them happy in open air. You can try misting, pebble trays or placing it near several other plants to raise the ambient humidity.
