What are these plants trying to tell me?

[PaphLover]

Phrag. Ingrid Portilla




NOID Brassidium


The phrag was on a heat mat under a T50 light.

The brsd in my living room window.
Both in semi-hydro.

I suspect they both might be from over-fertilizing.
I do tend to have a difficult time not feeding my plants at every watering.

I do flush with either tap water and then rainwater or soaking in rainwater (it's difficult to 'flush' with rainwater as I live in condo and only have a few milk jugs full) before refilling reservoirs.

Thanks for your input!

[MrHappyRotter]

The phrag is showing signs of vascular stress, something which doesn't necessarily have one single cause. It basically means that the leaves aren't getting the water and nutrients they need. Phrag leaves tend to be highly demanding when it comes to hydration.

Usually this is more of a think it through situation where you'll need to figure out what might apply to your situation. But some potential causes would be:

1. The plant isn't getting enough water, or has been allowed to dry out a little too much once (or several) times. Sometimes this is an issue where you're just not watering enough or the plant needs to be sitting in water (since we're talking about phrags), but it might also mean that your mix doesn't wick and hold enough moisture, so even if the plant is sitting in water, it simply isn't reaching the roots where it will do any good.

2. Too much fertilizer, fertilizer build up, nutrient imbalance issues, etc. Though this is probably unlikely, it can't be ruled out. Normally you'd expect to see the tips of the leaves die back, but if this is a very sudden or extreme issue, or in combination with the roots being too dry, it will result in vascular stress.

3. Unhealthy roots. Obviously the cause of unhealthy roots is also a complex topic, but if the roots are not healthy or are stressed (from being too dry, too much fertilizer, wrong potting media, recent repotting, etc), then they won't be able to keep up with the demands for water that the leaves need.

4. Excess transpiration. If your conditions are leading to very high rates of transpiration (loss of water through the leaves), then there could be a point where the roots & vascular system just can't keep up. Things like high temperatures, too much air flow, and low humidity can all contribute to this problem. Growing indoors, the plants are in a confined space and under artificial lighting. It's easy for heat to build up in and around the leaves. Low humidity is something that you can easily measure, if it's much below 50%, then you should work on that. If you're using fans, the breeze should be gentle most of the time. Use low fan settings and oscillation.

5. Disease. Lots of systemic diseases can put a strain on the vascular system. Fungal infections will often clog the xylem/phloem in the leaves, causing water imbalances and thus vascular stress. Though, I'd say sans other symptoms or signs of infection, this probably is the least likely candidate for your phrag.

What I'd recommend is think about your watering and feeding routine. Are you watering enough, and flushing after feeding? Is your water quality good (low TDS)? Examine the plant's roots, make sure they're in good shape. If not, take steps to resolve that. You might consider moving the plant to a shadier spot, and if you can swing it, and it's relevant, lower the temperatures a little to rule out heat as an issue.

[Ray]

If you have difficulty not feeding every time you water, don't fight it! Just be sure you're using only a very small concentration of fertilizer.

For example, if you divide 2 by the %N on the fertilizer label, the result is ml/L for 20 ppm N. At that level you can water to your heart's content, flushing as you feed.

For example, for a 13-5-15 formula, that's 2/13=0.15 ml/L.

[estación seca]

How long have you had the Phrag? It also looks like thrips or spider mite damage.

[PaphLover]

Thank you MrHappyRotter and Ray. Great info.

Here’s some more details:
I use MSU fertilizer rainwater formula 13-3-5 at the recommended dose: 1/4 tsp per gallon of water. Most of the time, when I'm not overzealous, I will fill the reservoir halfway with that concentration of fertilized water and fill the rest with rainwater (knowing that phrags prefer light feedings, based on their wild conditions of many having their 'feet' in river water).

I have noticed that phrags tend to drink up their reservoir water quicker than my other orchids, so I've also resorted to a second container that I also fill with rainwater just above the reservoir line and place the plant pot in that to give the phrag more to drink. In addition, I check the phrags on Wednesdays to see if they need a flush and more water before the regular watering on Saturday.

I did move the plant off the heat mat in case that was causing stress.

In addition to the MSU, I feed MagiCal 2-0-0, RootBuilder .5-.3-.5, and Orchid Champion (my attempt to find something like Inocucor).

Unhealthy roots: difficult to see now that they’re in semi-hydro. Here’s how they looked when I first got the plant in November. It is growing two new fans and has two new visible roots diving down into the media.





Transpiration: I do wonder about this and lack of humidity. I don’t provide extra humidity in my home, but I do live in Vancouver where if it’s not raining, it’s soon to be. It’s generally 50% humidity or higher in my home. I was hoping that having so many plants in semi-hydro grouped closely together and on heat mats would increase the ambient humidity around the plants. A little micro-climate, as it were.

Water: I’ve been collecting rainwater at work and driving it home with me (now that’s dedication, huh? ) for about a year now. But the water here in Vancouver is excellent and low in TDS, so if I run out of rainwater I don’t worry too much. It’s so good, in fact, that Nestle was bottling our tapwater and reselling it back to us (and probably into the US).

[PaphLover]

Originally Posted by estación seca

How long have you had the Phrag? It also looks like thrips or spider mite damage.

Certainly hope not, es!



I got it in November. I haven't seen any webs or creepy crawlies, and since moving my plants to s/h, any pest problems I was previously noticing (springtails, fungus gnats) have completely disappeared.