Masdevallia strobelii with yellowing new growth

[greenbean]

I've had this Masdie since July of this year. It's been growing beautifully and still is, except for one new growth that has turned yellow. It's growing healthy new roots and has several other new growths besides this one that are as healthy as ever. I see no signs of fungus or bacteria. It's growing in New Zealand sphag in a tank with indirect natural light supplemented by a fluorescent tube. Temps are in the mid 70's during the day, mid to high 60's at night. RH around 80-95%

Any ideas as to why this one growth is dying?

I'm pretty sure the damage on the older leaf is purely physical/mechanical. It was like that when I got it.

[ryrycochinco]

I would repot because your medium dosen't look fresh. Other than repotting your plant looks fine, new growths will die because of stress which can be caused by anything, don't worry.

[Bud]

right...it needs repotting and this time try a new media...one that will not make it darken its roots and stems easily...I understand this plant needs to be moist at all times; but at times try to let it dry before watering

[Zoi2]

Sounds like your culture is good, have you changed your water or fertilizer?
Joann

[ezil]

I've had this happen to me too, and my growing conditions are about the same as yours. I agree that you should repot, and keep the media "airy". Your choice of net pot is good, but try to keep sufficient air flow around the plant. These young shoots can react to any stress, but usually it's an isolated problem if the rest of the plant is healthy. Hope this helps.

[greenbean]

Thanks guys. From what ezil said, it sounds like just a quirk of that one shoot. I'll just keep an eye on it for now.

Joann, I haven't changed it's water or fertilizer. I use distilled water and a monthly application of weak fertlizer.

The moss isn't very old. It was potted in late July. Yes, it has a lot of algae even though I let it dry considerably between waterings, but it's quite airy. It looks rather wet because I took the picture soon after watering. As to the roots and stems, the roots are not dark (you can't even see them in that picture, so not sure where that came from) and the petioles are supposed to be that color in strobelii. I know how to grow in sphag. I'm one of the weirdos who can actually grow phals in moss because I know how to keep it airy and not overwater. But thanks for the suggestions!

[silken]

My masdies thrive in straight sphagnum. But I never let them get completely dry in between watering. I just re-potted mine and all the roots were a nice off white or white colour.

One of the people from equagenera told me if the moss is too high up on the crowns it can cause a problem. Not really seeing that yours is, but worth knowing.

[greenbean]

That's what my roots look like, off-white to white. I let the pot get really light before I water, but the moss is still damp, never crispy.

That actually is a useful tip, Silken, thanks! I see lots of roots on mine growing at the surface, so I don't think mine is too deep now, but I'll have to remember that when it's time to repot.

[silken]

Originally Posted by greenbean

That's what my roots look like, off-white to white. I let the pot get really light before I water, but the moss is still damp, never crispy.

That actually is a useful tip, Silken, thanks! I see lots of roots on mine growing at the surface, so I don't think mine is too deep now, but I'll have to remember that when it's time to repot.

Could it be that the roots are a bit too exposed on the top, and the one that turned yellow got too dry from being exposed? Otherwise I would think it is just a fluke.

[greenbean]

That is a possibility. I may have let it get a little drier than I usually do and the exposed roots got stressed. I'll keep a closer eye on my watering habits. But there are 2 other new growths that are right next to this one and about the same age, so I'm kind of thinking this may have been a fluke.