I've got this jade plant that was doing great for months, but recently the leaves started getting this brown squishy texture. I only water it like once every two weeks and it sits by a south-facing window. The soil drains pretty well too, so I'm confused about what's going wrong.
Check the drainage hole on your pot right now - if water's pooling or the pot doesn't have one, that's likely your culprit since "drains well" soil still needs somewhere for excess water to actually go. Jade plants are super susceptible to root rot, and even with infrequent watering, if that moisture can't escape, the roots will rot and cause that mushy brown appearance you're seeing. Have you checked if the soil feels soggy deep down, or is the pot sitting in a saucer that's collecting water? Also, is this happening to the lower leaves first, or scattered throughout?
Fungal or bacterial rot is probably happening even with light watering, especially if humidity is high where you're keeping it. Jade plants are drought-tolerant but they're also susceptible to root rot when conditions stay damp - and here's the thing most people miss: even if your soil itself drains fast, if the pot sits in a saucer or tray that holds standing water, or if you're misting it occasionally, the leaves can stay wet long enough for pathogens to take hold. South-facing windows are great for light, but if that spot gets warm and humid (like from a humidifier nearby or just general summer moisture), it creates the perfect storm for fungal issues.
I'd cut back the watering immediately - maybe every three weeks or longer - and make sure you're not letting water sit under the pot. If the mushy parts are already extensive, you might need to repot into fresh, dry soil and pull away any soft or blackened roots. Jade plants bounce back pretty well once you stop the moisture problem, but you have to catch it before too much of the root system is compromised. If it keeps spreading even after you dial back the water, you're looking at needing to propagate healthy leaves and start fresh since the roots could be totally shot.
The brown mushy texture usually means root rot, and even infrequent watering won't save a plant if it's sitting in damp soil - try unpotting it to check if the roots look black and slimy, then trim away any soft parts and repot in fresh, dry soil. A practical thing most people skip: after repotting, wait a full week before watering anything, and consider moving it away from that south window temporarily since heat can sometimes trick people into thinking the soil's drier than it actually is when the pot warms up in direct sun.
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