What causes a orchid to get yellow leaves?
1ft to light, indirect
3” pot with drainage
Last watered 2 years ago
2
Just to add to the advice already given, it doesn’t necessarily spell a problem. If it’s the bottom leaf and the plant is otherwise healthy, then it’s likely just the death of the leaf - each leaf has a natural lifespan. The bottom leaves are the oldest leaves, so they will die off first. A healthy phal should only lose approx 1-3 leaves per year, always from the bottom.
If you’re losing leaves from elsewhere or they are yellowing all together, that does spell a problem - common problems are: overwatering, underwatering (the way to tell is to check the condition of the roots - though it can be tricky to decipher as sometimes the roots will look the same for under watering and over watering), if the plant is and has been in bloom for a long time or multiple times that year, they often simply have no energy left to sustain the blooms and because they will always prioritise blooming, they often start shedding leaves so they can re-invest energy for the blooms. If this is happening, you can simply cut the flower stem off by cutting close to the base of the stem with sterilised scissors or pruners and add a dab of cinnamon powder to the cut to seal it and prevent infection getting in.
Poor fertilisation can also cause discolouration - that said, phals can survive for around two years without fertilisation, so it’s not a common problem if you’re using a good fertiliser and following the instructions on the fertiliser. Over fertilisation tends to lead to discolouration at the tips of the leaves, whereas the rest of the leaf is healthy - another way to test for overfertilisation is to look for salt build up on the media - if you notice white crystals building, that’s a sign of over fertilisation and you can flush the pot with plain water to help with this, and a repot as soon as conditions allow you to do so can help. Cheap fertilisers often lead to the build up of salts and it’s bad for the roots. Sun damage sometimes looks yellow at first, but it’s a different yellow than the leaf dying and will often develop a black ring around it - the tissue inside the ring will die off but the rest of the leaf will be functioning as normal (though sometimes the plant will choose to sacrifice it). As a general rule pf thumb, if you touch the leaf and it feels hot or warm to the touch, that’s a sign that the sun is too strong for the plant and needs moving or needs to be behind a blind/voile.
If you’re losing leaves from elsewhere or they are yellowing all together, that does spell a problem - common problems are: overwatering, underwatering (the way to tell is to check the condition of the roots - though it can be tricky to decipher as sometimes the roots will look the same for under watering and over watering), if the plant is and has been in bloom for a long time or multiple times that year, they often simply have no energy left to sustain the blooms and because they will always prioritise blooming, they often start shedding leaves so they can re-invest energy for the blooms. If this is happening, you can simply cut the flower stem off by cutting close to the base of the stem with sterilised scissors or pruners and add a dab of cinnamon powder to the cut to seal it and prevent infection getting in.
Poor fertilisation can also cause discolouration - that said, phals can survive for around two years without fertilisation, so it’s not a common problem if you’re using a good fertiliser and following the instructions on the fertiliser. Over fertilisation tends to lead to discolouration at the tips of the leaves, whereas the rest of the leaf is healthy - another way to test for overfertilisation is to look for salt build up on the media - if you notice white crystals building, that’s a sign of over fertilisation and you can flush the pot with plain water to help with this, and a repot as soon as conditions allow you to do so can help. Cheap fertilisers often lead to the build up of salts and it’s bad for the roots. Sun damage sometimes looks yellow at first, but it’s a different yellow than the leaf dying and will often develop a black ring around it - the tissue inside the ring will die off but the rest of the leaf will be functioning as normal (though sometimes the plant will choose to sacrifice it). As a general rule pf thumb, if you touch the leaf and it feels hot or warm to the touch, that’s a sign that the sun is too strong for the plant and needs moving or needs to be behind a blind/voile.
