Cymbidium with black spots on leaf tips

[Xylocarp]

Hi! So I'm a complete plant beginner, yet somehow got suckered into buying a beautiful cymbidium about a month ago. Over the past couple of weeks I've been keeping an eye on some black spots on leaves —*but I haven't been too worried about them, as some extensive googling tells me its quite normal for a cym to be a little bit spotty.

I took a photo of a particular leaf tip about a week ago — image 01 attached.

Today, this wing tip has yellowed and developed a large brown spot — image 02 attached.

I've now removed this leaf tip just in case. Does this look like any kind of bacterial/fungal infection? Other than these black spots and now this yellowing tip, my cym seems to be quite happy in his spot next to a frosted window, with flowers still perfect after a month and the leaves a nice apple-y green.

In terms of watering, I've had him a month and only watered twice — the last was two weeks ago, but I'm waiting a few more days to water as the top of his soil is only just dry.

I appreciate any help you can offer!

[estación seca]

Welcome!

You don't mention your relative humidity. Cyms in excellent growing conditions don't do this, but most people's Cyms do this. Underwatering with salt buildup can cause it.

If your medium drains rapidly and is well-aerated, you can water more often. If you're growing such beautiful Ficus lyrata and rhizomatous begonias, your humidity should be fine. I would vote for inadequate watering, or water with too high mineral content.

[Xylocarp]

Thanks! I would say humidity is on the high side*— I'm in Sydney, Australia in a sandstone house that requires a dehumidifier on at all times. If this is any indication, that ficus is beautiful and thriving after 18 months of near neglect (as in, I forget its there most of the time and water whenever I remember which could be monthly or longer)

I'm not entirely sure what media its in, looks like something sandy mixed with something else. Should I repot into different media like a perlite/bark mix?

I feel super cautious about watering it more often, because as mentioned the soil is still moist after two weeks. And I did break off a mushy root a while ago

[Roberta]

If the Cym is still moist after two weeks, and there's a mushy root, definitely repot once it has finished blooming. Small bark with perlite should be perfect. Then, of course, you'll need to water more. But the roots will be getting air with their water, which is what they want. When you repot, remove any rotted roots. It can go back into the same pot (from the photo, there's plenty of room) as long as is well-drained. I like to use time-release fertilizer on Cyms. Then you don't have to worry about fertilizing. You are headed into spring, so either a 6-month or 9-month formulation is fine. And once it is done blooming, it definitely wants to go outside.

[mexicowpants]

Just to throw a spanner into the works, my cyms tend do do this with too much moisture and humidity. Go figure.

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[Xylocarp]

Roberta - Awesome. Thanks so much! I will definitely repot in perlite/bark after it's finished flowering.

mexicowpants - Good to know, I think it might be a little too humid in my house. Once flowers are done I'll move it outside for some fresh air.

I'm actually getting kind of impatient waiting for the flowers to finish, even though they are beautiful - I just want to unpot and take a look at what's going on below!

PS. Image of flowers attached, just because they're pretty Tag says Showgirl Glamour Jane x Pepper Blaze Firestick.

[estación seca]

That is a beautiful pink.

[Roberta]

Originally Posted by Xylocarp

I'm actually getting kind of impatient waiting for the flowers to finish, even though they are beautiful - I just want to unpot and take a look at what's going on below!
.

It's a beauty. No need to rush... I really don't think that the house humidity is contributing much to the problem, the mix just holds too much water. When it does dry out, water it really, really well - so the water flows through the pot and runs out the bottom for a minute or two That will flush out salts that have accumulated, and also pull air into the root zone. After it finishes blooming, it will start to work on new growth, with new roots, and that's when potting is most effective. Orchids teach patience...

For growing, outside is best - Cyms need bright light (even full sun if not for too many hours) and a nighttime temperature drop (especially in the fall) to bloom. When in bloom, enjoy them in the house then back outside when they are done. Since this one has been in the house for awhile, when you put it outside start in a shady area, move to more sun gradually over a month or so to let it adapt to the brighter light.

Where in Australia do you live?

[Xylocarp]

Okay, cool - I'll water exactly as you've said once it's dried out. Speaking of, how dry should I let a cym get? At the moment the top soil is dry, but if I stick a toothpick in it's still slightly moist in some areas (not visibly dark, but bits of dirt still clinging to the stick)

I'm going away for a week in a couple of days, so I can either water it now before I go and risk it being too wet, or water when I get back and risk leaving it too dry. Ahh the dilemma

That's a good tip to move it gradually into more light. I plan to eventually put it on the upstairs balcony between two small potted trees for shade. The balcony has a glass door so I can leave it inside near that for a week to get it used to the light.

I'm in inner Sydney! I'm in a tiny cottage wedged between some taller apartment buildings, so I get a decent amount of shade as well as full sun - hopefully perfect for a cym

[Roberta]

Definitely water before you leave. Water well... no spritzing. As for location... sounds good. Your climate is pretty much the same as mine (just seasons reversed). Perfect outdoor climate for Cyms. (They can take winter temperatures a bit below freezing, -1 to -3 deg C - with no damage even to flowers, and put up with whatever summer brings as long as they have a bit of shade)