Hi everyone :)

My philoendron Brasil isn't doing so well... a couple of months ago the leaves started taking on a 'matted' appearance, getting orange blotches, gradually losing colour and falling off, leading to 'balding'. The problem mainly affects older leaves near the soil, but a few younger ones have also fallen off like that. Adding to my misery, newest leaves on the plain green philodendron that sits next to the Brasil are matted (presumably early stages of yellowing)!

I changed flats a month ago, so the Brasil was moved from a northern window to 9 feet away from a western window, and is now in lower humidity (~45) and higher temperatures (22-26 C) than before. I don't fertilize my plants that often and mix my own soil (coco coir, perlite and worm castings).

I'm wondering if anyone recognizes this pattern of leaf matting/yellowing and could point me in the right direction. Is this plain old overwatering, or some nutrient deficiency? I checked the roots today, and the soil was very moist (I did water it a few days ago) with some roots circling the bottom of the pot but nothing tragic. Roots were brown in colour, but not squishy.

It does look like the dreaded root rot. Very hard to bring plants back from that.

It looks like it may be a watering problem. How do you determine when the soil is dry enough to need water? About how often is that? How much do you then give it?

Thanks both for your input, it's greatly appreciated!

I use a moisture probe (I know many people say it's not reliable, but I have not had any problems for 2 years, so I don't think it's the probe's fault). I water the plant every 9-14 days and when I do I soak it thoroughly in the sink. I did repot the plant a month before I moved, and if I remember correctly, I did not have that much perlite on hand - could it be that the soil mix is not well-draining enough?

I removed as much of the old soil as I could yesterday and planted it in fresh coco coir, worm castings and plenty of perlite.

If it is root rot, can I cut up the plant and propagate the leaves in water?

That sounds good. When your plant is happy is the best time to snip cuttings. The info in this message about Pothos applies to this kind of Philodendron too:

https://garden.org/thread/view...

Just an update in case anyone else is having a similar problem:

I've now identified thrips on this plant (and two others) and believe they are responsible for the damage. The three plants were sat on the same bookshelf, so the bugs were able to jump between them. I binned both philodendrons, which were both too far gone (I took some cuttings from the Brasil, but spotted a thrip on one of them today, so I chucked the lot), but really determined to save my maranta. Started neem oil treatment and DE is on its way in the post

Still gorgeous plants from the photos.

First guess, too much water, too little light, recovering from transplant.
Looks like your plants aren't utilizing the amount of water they're receiving, which depends on how much light they're getting.

When you say you soak thoroughly in the sink, are you saying you water well or that the plant literally sits in still water before draining?

I employ both methods, but might be something to consider.

Thanks for your input, Humboldt. The plant definitely received less light than in my previous flat (northern window vs 9 feet away from western window) - that, combined with not enough perlite in repotting mix and the actual flat move made it more susceptible to a thrip attack (I guess). I don't think it had root rot (I never let my plants sit in still water, unless I'm bottom watering, but this particular plant was never bottom watered), so if it wasn't for the thrips I probably could have saved it...