Causes of brown leaf tip on new Phrag growth?

[varda.elentari]

I need some help please! The leaf tip on the new growth of my Phrag. Hanne Popow turned spotty and then a solid dark brown. I recently bought the plant and repotted it in a mix of bark, lava rock and perlite. I've been watering mostly with RO water and sometimes aquarium water, leaving some in the saucer for the plant to soak up between waterings. I haven't given it fertilizer yet because I've been giving it Kelpmax to encourage new root growth first.

My mother watered it at least once, possibly with tap water (though I've asked her not to water my orchids!) and I've read Phrags can be sensitive to chlorine but would a single watering have such an effect? I've also read brown leaf tips could be a sign of calcium deficiency but I haven't found enough sources confirming this to be sure. If that's the case, should I water with aquarium water rather than RO? The fertilizer I have now doesn't seem to contain calcium but I know my tap water has good levels. That's what I use in my aquariums, dechlorinated of course. So if I used that to water, the plant would get calcium but I don't know if there are other things in tap water besides chlorine I should be worried about.

Any help would be much appreciated because I'm relatively new to keeping Phrags. Thank you!

[estación seca]

This is usually underwatering. A single tap watering would not do this.

Edit: Phrag species mostly grow in or right next to streams and ditches. Think of them as bog plants. They should stay very moist to wet. Like other bog plants - some Lobelias, Sarracenia, mint - phrags look and grow poorly when they aren't constantly moist to wet.

I have found they do very well in semihydroponic culture. The lower portions of the roots usually grow into the water reservoir.

[varda.elentari]

Thanks for such a quick response! I'll up the waterings then and make sure there's always water in the saucer. I wonder if my mix is too open for it though. (I have a huge fear of root rot so I tend to err on the side of underwatering and planting in more open mixes.)

What do you think about watering with aquarium water vs. RO?

[Mr.Fakename]

My Phrag longifolium did something similar when I bought it.
Only tips of old growths darkened and it didn't spread that much, I assume it was related to going from high humidity greenhouse to ~30% RH.

If you use RO you'll need a complete fertiliser to avoid deficiencies.
I use tap water for all plants and never had an issue with chlorine, even with finicky stuff like Dracula.

[Roberta]

Originally Posted by Mr.Fakename

If you use RO you'll need a complete fertiliser to avoid deficiencies.
I use tap water for all plants and never had an issue with chlorine, even with finicky stuff like Dracula.

There's tap water and then there's tap water... Mine is marginal for Phrags, Pleurothallids also improved greatly when I got RO. Others in my general area have tap water that is so loaded with minerals that it kills nearly everything and RO is really necessary. (What comes out of the faucet is "liquid rocks") So, it's important to know what is in one's tap water... The water provider should be able to provide an analysis. For those with wells, usually there has been an analysis at some time, if nothing else to determine that it is OK to drink. So if the solids level of the water is moderate (like below 100 parts per million) it's fine for most orchids. Chlorine isn't particularly a problem. At least in much of the US, water doesn't even have free chlorine - chloramine is used for disinfection, not volatile but also not a problem.

[Keysguy]

Varda- help me understand your whole environment picture so I get a better picture.

My conditions will be nothing like yours but I've always had good luck with Phrags and currently have a dozen different species and hybrids including a Hanne Popow I just got a month or so ago from Ecuagenera.

In general------ they like warm days with light just shy of cattleya light and cooler nights that provide a nice deposit of dew. this time of year I feed weekly with a blooming formula until summer then go to the growth formula the rest of the year and include a little Epsom Salts each time I feed no matter what else I'm feeding. KelpMax monthly and CalMag quarterly.

Your mix sounds OK but I'd pull it and add in several sprigs of sphagnum to help it hold more water. You honestly cannot overwater them. Mine are watered thoroughly every 4 days plus are just downwind from the misters that run on my hanging orchids 2X/day. This is all in addition to whatever rain we get as they are outside year-round and in the summer growing season, that's a LOT of water.

All that being said, Phrags still tend to get brown leaves. It starts at the tips and works its way back and I don't touch it until the whole leaf is brown and dried out, then snip it off. I've never stressed over it and I have some monster specimen plants so I honestly don't think it's anything to worry about.

The only no-no is wet AND cold! Hence my question about the bigger picture of your growing set-up.

[varda.elentari]

Thank you all!

@Mr.Fakename
That's the thing. If it was an old leaf I wouldn't be surprised but this is the first time I've seen this happen to a new leaf on a developing growth. Hence my worry I'm doing something wrong. Thanks for mentioning humidity. I had forgotten that might be a factor here as well.

@Roberta
I'll take another look at my city's water report. Thanks for the 100ppm guideline - that's exactly the kind of info I need! So chloramine is okay for plants? I know it's as bad for fish as chlorine so both need to be treated before tap water is used in an aquarium.

@Keysguy
I'll definitely add some sphag to the mix before I water next time. Thanks for the tip. As for my growing set-up, it's very low-key at the moment because I've only recently gotten back into orchids. Just room temperature, 4-tube T8 fluorescent fixture (planning to replace with an LED grow light soon). Room humidity is low I suspect but the plants are above a large open-top aquarium so there's some localized humidity.

[Roberta]

Originally Posted by varda.elentari

@Roberta
I'll take another look at my city's water report. Thanks for the 100ppm guideline - that's exactly the kind of info I need! So chloramine is okay for plants? I know it's as bad for fish as chlorine so both need to be treated before tap water is used in an aquarium.

Yeah, fish are a whole different game. The amount of chlorine or chloramine that is in drinking water is no problem for plants but kills fish. Just for reference, my tap water ranges from about 200-350 PPM. Calcium bicarbonate is most of it.. so plants that get tap water get plenty of calcium. Most of the larger plants do fine with it - Cymbidiums, Catts, Oncidiums, etc get city water no problem. Pleurothallids and some others have greatly improved with RO - they get MSU pure water formula with cal-mag. (There are some southern California areas not far from me that are more like 600 PPM... many people who have that stuff use RO for everything. Cymbidiums and larger Catts don't particularly care, but most other orchids don't like it much. )

[Keysguy]

Roberta's points on the water quality are spot on. I'm just lucky that since I moved my collection to where I can grow outdoors year-round, I don't even think about it anymore because whatever watering I do with city water is just supplemental to mother nature's.

If you want to see a cool picture of a Phrag in nature, go check out my response to Clawhammer's recent post on his Ecuagenera purchases.

[varda.elentari]

That's good to know about Cymbidiums - they're my favourite genus and I'm hoping to grow more of those as well. My tap water was somewhere around 200-250 ppm last time I checked. So that would be fine for the Phrag?

@Keysguy
Those are gorgeous pictures!

EDIT: Roberta, I just looked at your page and I was just blown away by your collection! And the Cyms!!