I am having a very basic problem despite adjusting many aspects of its management. NO matter what I do every orchid I own starts rotting at some point... I have adjusted the watering heavily (going from 5 to 12-14 days). Every plastic pot has additional holes I made. I only use high quality bark substrate (from Substral). Humidity is always 40 - 55 %. Fertilizing happens frequently in very very diluted form... I make sure to let the water drip of so the plants are definitely not sitting in the water. They have huge SE window with plenty of light...
Where am I going wrong? I also remove the little sponges they have in their original substrat to avoid a wet crown... the last two I repotted at first seamed extra happy. All of a sudden, roots are starting to dry/rot?
There are no pests presents... my last thought is maybe hard water? Any ideas? I have a plant with four (4!) keikis with previous strong healthy roots that just started to rot in seemingly perfect set up...
There are several potentials sources of root issues.
The most common is suffocation, when the potting mix is too fine or has become compact over time, allowing water to fill the voids between the particles, cutting off the gas exchange pathways.
Another is poisoning, often due to the accumulation of minerals in the medium. If you allow the potting medium to dry between waterings, that is accelerated, although your "very very diluted" description suggests that fertilizer may not be the issue, while your hard water may be.
Both can be remedied by more -frequent repotting - how often are you doing that?
I only have Phalaenopsis. It's winter now where I live and my room temperature never drops under 70 F. I water so inferquently because I wait for the whole substrate to dry out. The bark I pot in is large, there is plenty of air pockets...
Most orchids I repot immediately after purchasing... hard water seems to be a possibility. Any idea how to solve that issue?
In my experience, roots rotting can happen for a number of reasons
1) If roots are damaged while moving from old medium to new
2) Not enough air can get to the roots
3) The disease causing the initial rot still very active
4) Newly potted orchid is not stable in medium so that it moves around. With some orchids, this can cause damage to the roots which allows disease that causes rotting to enter the roots.
Most of these issues can be solved by making certain the orchid is steady in the pot and making certain that more air can circulate around the roots.
Choose a medium that does not rot/compact quickly...perhaps one with more rock or all rock. The pot should also allow air to access the roots. Make certain that there is space between the pieces of medium so that air can move around the roots. For orchids that grow on trees and rocks, the medium is meant to keep humid air around the roots and to hold the orchid in the pot.
Before potting the orchid in the new medium, expose the remaining roots or, if rootless, the root area to air for a few days to give it a chance to heal.
If the orchid is rootless, wire/stake it above the medium so that the new roots grow down into the medium. I use lava rock as a medium and so I water the rock with rootless orchids to provide humidity to the root area to encourage root growth.
Most phals don’t want to get bone dry between waterings. Some species want to dry quickly between waterings, but they still want frequent waterings.
If your medium is very chunky and all the other growing conditions are correct, you can water almost every day without worrying about rot. If instead, you let the plants get too dry on a regular basis, root health will decline over time from the stress.
How close are they to the window? I have my phals right up against a large south facing window with sheer curtains to diffuse the direct light, and I’m farther south than you are.
I also don't think the problem is rot. Phals. tend to rot when they are too cold, or too hot and extremely humid. What are you seeing wrong with your plants? Could they be getting cold if they are close to the window?
__________________ May the bridges I've burned light my way.
Okay, I found one of the before/after pictures. 1) the orchid was repotted for cca 10 days. 2) two months in, roots thinned out, some dryed out. Now, there is white mold on them. Surprisingly, the leaves are still firm but in my experience not for long….
I do have them very close to the window as there is no other place I can put them (I live in the dorm)…
From the pictures you can also judge my repott (please do so). This praticular orchid does have some ongoing root growth tho and was packed extra firmly when bought with little ventilation and a moss plug.