New phalaenopsis leaf yellowing - Orchid Board

spt4261 · #1 09-27-2017, 11:25 AM

Long time reader, first-time poster here! So, I have a grocery store phalaenopsis that I brought back from the dead. It's had a mealybug infestation and crown rot. Its leaves went limp and leathery and, on more than one occasion, I almost threw it out. In the midst of all of this, we moved to an apartment with north facing windows that prompted me to start supplementing with grow lamps. The phal suddenly revived with lots of new root growth, new bloom spikes off of the previous cuts, and a new tiny baby leaf. I thought everything was back on the right track until two days ago when the new leaf turned yellow (see attached photos). The plant is in a clay pot and is definitely not over watered and is showing no other signs of distress. I'm guessing this might be from too much light from the grow lamps? I'm not sure how to modulate the light from my lamps (particularly since the rest of the orchid seems to be thriving under these conditions). My biggest question is what will happen to this leaf? Any chance it will continue to grow? Should I cut it away?

camille1585 · #2 09-27-2017, 11:37 AM

Welcome to Orchidboard!!
I saw that you posted this thread twice, the first time in the wrong place. SO I've deleted the thread you created in the Cymbidium forum. If you make that kind of mistake again (happens to the best of us!), it's usually easier to contact a moderator by PM to ask to have the thread moved. Having duplicate threads creates other issues, with replies in 2 places so people don't necessarily know there is a second thread.

As to your post, you are on the right track with care for your Phal, but I'm also a bit stumped about the yellow leaf. It's not from too much light, you'd see burning or purple coloration on the existing leaves if it was that. How do you water? Any chance that you got a little bit of water in the crown by accident? I would let it grow and see how the rest of the leaf comes out, but keeping a close eye on it. Is it dry, or soft?

spt4261 · #3 09-27-2017, 01:08 PM

Camille! Thanks so much for taking care of my extra post. I couldn't figure out how to delete it so now I know. As for my phal, I hadn't considered that it could have been caused by trapped water in the leaf. Interesting. The leaf is yellow but also has a dry brown edge, which made me think it was burnt. However, as you suggest, it's hard to imagine how just the new leaf would burn and not the rest of the plant. I'll watch it and see what happens.

estación seca · #4 09-27-2017, 02:21 PM

Welcome to the Orchid Board!

A struggling plant in a smallish pot with large chunk new bark, making a new leaf and 2 new flower spikes at the same time.... I think it self-pruned due to not enough water.

Usually water in the crown leads to wet rot, not drying out. Too much light may have had something to do with it, but maybe not. My experience has been emerging leaves adapt the the high light and older leaves sunburn.

The plant is also making new roots, indicating it is ready to absorb more water. I would increase watering. How are you deciding when to water? In large-chunk bark like this, in a smallish clay pot, you might be able to water every other day, depending on ambient humidity and temperature.

Some people pour water through the pot to water. Many people who grow in clay pots, in large bark, take the plant to the sink and let it soak in a container of water for an hour or so, to make sure all the roots and medium are good and wet. Then they let it drain.

By the way you can send messages to people by right-clicking their user ID.

Dollythehun · #5 09-27-2017, 02:28 PM

I agree with ES. In a clay pot with large bark you practically cant' over water. I also think its too dry. I water thoroughly, making sure the pot si wet too. Then I lift the pot for weight. When it starts to feel light again, I water. Watering depends a lot on the environment. If you added more light, more than likely, you will have to add more water.

spt4261 · #6 09-27-2017, 03:12 PM

Okay, this is starting to make more sense now. I had a bunch of root rot in several of my orchids in the late spring and I think I might be overcompensating. I moved everything into clay pots with lots of air holes and much coarser bark. I also took them off a regular watering schedule and now mostly just go by the color of the air roots and the dampness—or lack thereof—that I can feel with my finger. All of my orchids seem happier with this method, are spiking and have new growths, and have no root rot, thank god. I've been watering this sad phal everyday, but I have missed a day or two here and there so that might have done it. I'm going to try the soak method and see if that helps. I've only been growing orchids for about a year so this is the first one to respike so I want to make sure it's happy. I both love and hate how temperamental these plants are.

spt4261 · #7 10-02-2017, 04:51 PM

Okay, everyone, I'm back with more problems. I've been soaking my orchid since I posted previously. The medium is notably more moist, which I think is good. However, the small new leaf has completely turned yellow and dried up. Now the yellow is spreading across the base of the crown (I've uploaded a new photo to the original post). Is this crown rot?

estación seca · #8 10-03-2017, 02:33 AM

I think the small leaf was already destined to die when you first posted. The new root still looks good, so I think the plant should recover. It is still responding to the dry period, and it is possible you will lose another leaf.

You will not be able to save the threatened leaf by overwatering. It is a matter of the plant achieving a balance between root and leaf mass. Continue to water when almost dry; resist the temptation to overwater. If you rot the roots at this stage, the plant will not likely recover. As the plant makes more roots, it will make more leaves, and it will become a healthy plant again.