Angraecum didieri dying? - Orchid Board

critterguy · #1 04-28-2014, 03:03 PM

Have an Angraecum didieri that is in a terrarium as shown here.

Pygmy chameleon tank - Dendroboard

top is full screen. Lighting my a LED aquarium light. Gets sprayed anywhere from 1-2x per day-I avoid thoroughly wetting it. Seems like it is able to dry out in a few hours. The tank has a screen top and good ventilation. A few inches away and sprayed more liberally Stelis hirtzii is growing quite well.

The plants came in a pot so I un-potted it, removed most of the substrate, and then tied it up against the hygrolon tube you see in the picture.

Some of the roots have died back...but the plant has also grown a few new roots. However today I noticed three lower leaves were black and dying and a couple more fell off when I touched the plant. Is it getting too much water? I find that hard to believe.

Leafmite · #2 04-28-2014, 04:30 PM

I grow a few of these and I'm guessing that it is just too moist without a strong enough 'breeze'. I would take it out, remove anything that is black, dip everything but the roots in isopropyl alcohol (to hopefully kill the fungus or bacterial infection) and then keep it on the drier/warmer side for a while, with just the roots getting water. The didieri is a pretty tough one and will usually recover. Good luck!

GardenTheater · #3 04-29-2014, 08:35 AM

I agree that it's probably too moist. I have mine at around 50% to 70% RH (relative humidity) and not much air circulation. It's roots are hanging past the mount surrounded by Spanish moss. I mist only roots 5 or 6 times a week. It has sent out new roots and 4 keikis since I got it several months ago. I cut back on heavy misting when I noticed some rot on the roots and never misted more than once a day. My temperatures are between 60F and 80F. If you have 80% RH, you might be able to mist roots less often than I do.

After posting this, I checked the Baker culture sheet and it indicated this plant grows where there is a 5 month dry season from Sept to Jan. It would then draw moisture from just morning dew, if any, and humidity on most days in the dry season. Misting roots once in the morning simulates the morning dew.

gravotrope · #4 04-29-2014, 10:33 AM

It may have gotten too much water, it may not have been too much water...the point is that it got black rot and the watering schedule encouraged that to proliferate. It can be tough to bring a plant back from this, since it depends how far along it is, but also possible to save it. I bought a plant recently that was already rotting and didn't notice until it was almost too late. The isopropyl alcohol is a decent move, but it would be better if you dipped the entire plant in 1.5% hydrogen peroxide for a 5-20 minute soak... meaning equal amounts 3% peroxide and water, but you can eyeball it since up to 3% for a direct application is okay. That way you take care of any fungal infection on the surface of healthy root tissue AND give the roots oxygen, as well as kill the surface rot on the upper areas of the plant.

Do not put the plant back in the tank. After you have treated it and let it dry out completely (this should be about two hours later after your soak, minimum) you need to give it a systemic treatment, since you have already treated the surface rot. I use a combination of garlic water (1 clove of garlic, smashed or roughly chopped, let to soak in any amount of water for about 10 minutes before it is ready) and aspirin water. Uncoated aspirin from the dollar store works best for this, at anywhere between 1 tab/gallon up to 2 tabs/gallon, but it takes some shaking or stirring to dissolve it in water. You don't have to use both combined together, but either one would work well as a systemic. When a plant is this badly stressed, you need to tell it to grow, isolating the infection and cleaning it aren't enough to see a rebound in any short amount of time. I add superthrive and liquid seaweed at whatever concentration a quick sploosh and a glug per gallon of water may be, but this is probably best applied the next morning after an attempted rescue to allow the systemic application a bit of time to work before trying to stoke new growth.

this plant likes air movement and bright light, but it is highly adaptable, so if there is a drier part of the same terrarium, you should move it there after you clean out the entire thing... sterilize the entire cage including the mist spout and light surface with peroxide or diluted bleach and get new mounts. the rot can kill your other orchids and plants in there if it isn't devouring them already.

a monthly application of diluted peroxide will help keep things in your cage oxygenated once it is clean, just remember to let everything dry out. also a monthly application of the aspirin also will help your plants stay healthy, so dose with one or the other every two or three weeks and all your plants should be fine even if the rot isn't totally eliminated from the chameleon tank.

No experience with Chameleons here so I don't know what is safe for them at all.

critterguy · #5 06-06-2014, 02:38 PM

Thanks all for the excellent advice! It turned out to be much too late for this plant though. It will help with any in the future if I face this again.

Raqsharqi · #6 11-11-2014, 06:11 PM

I found this thread while searching for information on how to do CPR on MY angraecum didieri. I bought it as part of a "easy, beginner's collection." It did okay in a shady spot over the summer, but when I moved it to our new greenhouse, it ran into problems. I think I burned it, because the surface roots and most of the leaves turned brown. I sent a photo to the nursery I bought it from and asked for advice. Instead of advice, I got scolded for killing a plant that anyone could grow and was told to stop buying orchids until I knew enough about them to care for them properly. I politely remarked that the other 4 I bought from them are doing just fine, but I didn't get any advice other than "keep it happy" and "you're the first person to ever have trouble growing this orchid.
The plant has two dessicated leaves left, but a pretty good root system. I think in my attempt to keep the plant "moist" while at the same time trying to dry out the roots, I misted too much and gave it crown rot. I poured hydrogen peroxide on the crown and repotted it in a very loose mixture of moss, bark and rock in a plastic net basket. I also moved it to a brighter part of the greenhouse where it gets more sun than my phals get. I misted the potting mixture with KLN. When the mist hits the roots at the top, they turn a nice green. Is there anything else I should be doing to save this plant?

gnathaniel · #7 11-11-2014, 10:39 PM

Hey Raqsharqi, tell those rude nursery owners they can't hold themselves out as experts until they've killed at least their own weight in orchids, and that you want to see proof.

Personally I think Ang. didieri is a bit finicky and prone to sudden death, in my custody anyway. I grew one moderately well on a cork mount with some moss around the robust root system, but it never held on to many leaves and I traded it away. The two I've tried since then both perished within months of coming to live with me. So maybe not the hardest species for which to provide proper conditions (whatever they are), but seemingly not very forgiving either.

Then again, at this point I've killed somewhat less than 1/8 my weight in orchids (though I am a pretty large guy), so take my opinions with a big grain of salt.

Leafmite · #8 11-11-2014, 11:29 PM

The didieri needs really good air flow and if the leaves get wet, they need to dry quickly. This past summer, we had too much rain and not enough breeze and mine were toast. I should have kept them out of the rain. I had them for quite a few years. Sad. I haven't bought another yet.
The beginner Angraecum should be the Magdalenae. The leonis and distinchum are also easier than the didieri.

calvin_orchidL · #9 11-12-2014, 11:58 PM

Interesting observations! I have had different experiences - for me at least, didieri has been the easiest, whereas magdelanae grows at the speed of a snail, and leonis never blooms.

I grow mine under lights in the brighter area. It has very little moss on the roots, and grows on a cedar plank. It goes bone dry in between watering in the winter, a little wetter in the summer. It takes tons of abuse, but typically on the side of lack of water rather than over watering. I'm finding with the angraecoids that with adequate humidity and airflow, you can actually get away with less water than you think.

Leafmite · #10 11-13-2014, 12:34 AM

I bought my mag as a tiny seedling and immediately put it in a six-inch basket pot with red lava rock so I would never need to disturb the roots. I water it well year round and give it high light (the top nearly touches the T5's). In less than four years, it reached blooming size which was pretty impressive to me, given the size when I bought it.
The didieri were doing perfectly fine until this summer. As you have indicated, they prefer drier conditions. This summer was just not to their liking. :|