new root care in Guarianthes

[nightwings]

I seem to have a problem timing my watering when aurantiaca, skinneri, bowringia, guatemalensis, etc. They start to initiate new growth and roots, then the roots grow about 7-8mm, then turn brown or dry up. I usually give in to temptation and spray with water to keep them from drying, but they still crater on me. Not sure what they really need because my humidity varies a lot, usually pretty low in the winter and spring, even in my small greenhouse. Should I just ignore them? I do not have this problem with my Broughtonia, but do, to some extent with the Cats. I do use R-O water to some extent, but usually only about 90%. I have misters on every hour for about 15 minutes during the day (aimed at the floor) and an evaporative cooler when needed. Just not sure what I am messing up. Thanks! Hoping for enlightenment.

[ksriramkumar]

Aborting of roots could be due to various reasons. Posting a picture would help diagnose better.

[Chris in Hamilton]

I had put it down to not watering frequently enough but would be interested in hearing other members thoughts as well. So far, all of the plants that this happened to have grown new roots from the dried up looking ones but preventing it in the first place would be nice. This does only happen with Cat.'s.

[raybark]

Without seeing them, and based only on what you describe, I can think of three things that can - separately or combined - lead to that: insufficient watering, insufficient humidity, or something detrimental in the water - excessive dissolved solids, or improper pH, for example.

[Chris in Hamilton]

Without seeing them, and based only on what you describe, I can think of three things that can - separately or combined - lead to that: insufficient watering, insufficient humidity, or something detrimental in the water - excessive dissolved solids, or improper pH, for example.

Hopefully Matt can get a clear shot. Mine are always poor but I'll try this evening.

[78Terp]

Have a water softner?

[Chris in Hamilton]

This is the problem I am having but don't know if Matt's is the same. The plant is Laelia fidelensis that I won in a raffle but it happens with others as well. The roots start to grow really well but then the root surface or tip dries out and sometimes develops dead dry areas. They always seem to heal and start growing again but it would nice to have it not happen at all. You should be able to see the two new tips at the edge of the pot. Those are coming from a root that dried. Also should see dry spots on older roots. There were no roots on the plant when I got it in December. It is about 1' below fluorescent light and gets a few hours of afternoon-evening sun. I will be setting up a rain barrel this week but use tap water with PH of about 6.8. Fertilizer is 25-10-10 made by one of the larger companies and intended for orchids. Half strength once a week. Humidity runs around 70%. I do know I was not watering enough until a month or so ago and think that was the problem but other opinions would be much appreciated.

Attachment 80709

[raybark]

I can't see the attachment, but what does "half strength" mean? (Correct answer: Nothing, unless you tell us the v/v full strength.). Producers of orchid fertilizer want to sell fertilizer, not grow orchids, so it is best not to trust what they recommend, but to make a logical decision on the nitrogen level to be applied, and use that always, letting the formula ratios be the variable as you experiment.

Another caveat for you: when you start using rain water, it will have no buffering capacity to speak of, so mixing it with that same fertilizer formula might result in a really low solution pH.

[Chris in Hamilton]

I can't see the attachment, but what does "half strength" mean? (Correct answer: Nothing, unless you tell us the v/v full strength.). Producers of orchid fertilizer want to sell fertilizer, not grow orchids, so it is best not to trust what they recommend, but to make a logical decision on the nitrogen level to be applied, and use that always, letting the formula ratios be the variable as you experiment.

Another caveat for you: when you start using rain water, it will have no buffering capacity to speak of, so mixing it with that same fertilizer formula might result in a really low solution pH.

Hmmm, not sure what happened there Ray but I'll do another post.

[nightwings]

more info:
I do not have a water softener and mainly water with a 90-10% solution of Reverse Osmosis to tap water
our tap water has very high TDS, around 1600ppm, but most plants survive fine on it. I occasionally flush with tap water and my misting system uses the tap, so some does settle on the plants. I will try to take some pictures for examples, but not sure I can create small enough files or how to attach as I have been having trouble since I "upgraded" to El Capitan on my MacBook Pro.