Root Burn or root rot?

[khimnavany]

Hello,

I bought a Phalaenopsis orchid just a week ago and I have noticed that the tip of exposed roots are turning black. I have been using tap water rather than distilled and I have not fertilized it yet.

I have watered it twice so far, and only when the barks were dry with no condensation in the plastic pot.

Is this root rot or root burn? And what should I do about it?

[estación seca]

Welcome to the Orchid Board!

What are your day/night temperatures? Humidity? What kind of lght is it getting?

What you show is common in plants from a high-humidity environment moved to a low-humidity environment. It is not rot. As long as the roots inside the pot are healthy and other conditions are good the plant should grow.

[khimnavany]

Thank you for the warm welcome!

Day/night temperature are 23/19°C. My hygrometer will arrive tomorrow but my home is definitely dry and the medium dries up within 4 days (so far).

The orchid gets about 10hrs of light from a western window with non direct sunlight.
As we are entering the winter months it'll get only 9-8hours until February. I do use artificial light between 3AM and 7AM just so it adds up to roughly 12-14hr during winter.

I'm glad to know it's neither burn nor rot, that's a relief!

[estación seca]

I think it's the dry air. If you water properly it should grow fine.

[Orchidtinkerer]

Hi khimnavany,
regarding your question, I think you have a case of both root burn and root rot but that is not unusual when buying a new plant and not the most vital things to look for. Roots can regrow - your plant looks in good condition overall so don't worry about the root tips too much for now - BUT - try not to keep them soggy. See the silvery root on the first picture - that has a good moisture level, then the green wet looking roots are too soggy, this in turn has turned the rotted root ends soggy and they will continue to rot. As soon as they dry the rot will stop and dry up.

I think your substrate is on the verge of going bad so will need to be replaced, that will remove any stored fertilizer that will be more of an issue than you using plain tap water.

So either repot now which is best and would give your pot a chance to dry out or let the pot dry out but if it takes too long, roots might start to rot.

When I first started in the hobby I was looking at the substrate to see when it needed watering but my advice which will hopefully help you most is ignore the substrate, it should look mainly dry all the time, you need to look at the roots and see how much moisture is in the roots - not the substrate. Once the roots become silvery further and further down the pot till only a few roots remain green (which will be at the bottom of the pot as gravity pulls water down) - that is when you water again.
In my climate a phalaenopsis generally averagely drinks roughly 30ml of water per week, but that is a very rough guide as in summer this can double and in winter it can halve - look at the color of the roots to help judge if the pot still has moisture or not.
It helps to weigh the pot when you think the plant needs watering again (the minimum), give it 30ml water, weigh the pot every few days and see how long it takes to get back to the minimum weight - work out how much your plant is drinking in a week. Stick to watering that amount. If your pot can hold 5 times more water and you soak it, it can take 5 times longer to dry out which is too long. So know what your plant needs in a week, water it that much and stick to it. If the pot can hold too much water you cannot soak it or just let water run through it as it will become waterlogged.

An orchid is not a cactus and needs constant access to water but it drinks very little, probably as little as a cactus so it takes a little bit of experience to get to know how to treat an orchid, just make sure it is never as soggy as in your pictures, one green root is all it needs to keep it happy(the rest being silvery), once you know how much your plant needs for a week and the weather stays the same you can then safely water that amount knowing it will be plenty for another week, just stick to the plant being able to dry out every once in a while, if you saturate the whole pot, it will not be able to get to that minimum point or will take so long the plant will die before it does. So dryer rather than wet but don't let it dry completely. Roots need air as much as water, never drown the roots.

Stick to that and you should do fine.

[Roberta]

For a start, my inclination would be to repot - probably small bark rather than sphagnum (which has its benefits, but also can be tricky to get right) Bark will give you air spaces. Also... how good is the drainage of that pot? If it is one of those soft pots that Phals are often sold in, with a single hole in the bottom, drainage and air circulation are poor. It looks like that plant has lots of good roots, so once placed in a better environment, will do better (and you won't have such a tendency to lose new roots) When you remove old media, don't be too aggressive... take what comes off easily, but if some bits stick to roots, leave it. Phals like "humid air", not soggy wetness. Once you put it into fresh bark medium, it will need watering more often - hold under the faucet and let water run through, which also pulls air into the root zone.