Monnierara millenium magic witchcraft -- growth cycle?

[MJG]

I bought this orchid online and have had it for a month. It looked just like this when I received it, without the yellow leaf. A week ago another leaf turned yellow and then died. Now this one is going. I am trying to understand why. I am also very confused about the growth cycle.

Is this leaf loss part of this orchid's normal cycle? It seems way ahead of what I understand is typical. Everything I read says hold back on watering until there's root growth, sometime in May or June. Then it's supposed to grow leaves, begin to lose them late summer and flower in the fall. This one showed up in May with tons of roots, all leafed out. I've been watering and fertilizing. Is it now heading to the part of the cycle where it sheds its leaves? It seems too soon, and I don't see any sign of flower spikes developing yet.

Another possibility for the leaves yellowing could be proximity to my grow lights. Or could it be pests or fungal?

Any help in understanding this beast will be greatly appreciated.

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From what I've seen here on Orchid Board, insufficient watering during the growing season and failure to recognize and eliminate spider mite attack are the main causes of failure with these.

First, Spray for spider mites, whether you think you have them or not! Use 1 Tbs / 15ml liquid dish soap in a quart / 1L water and be sure to wet all surfaces of all leaves, and the plant body.

Second, Where did it come from? What I see is a new growth that has completely developed. Most people growing these in the US will not see this until later in summer, or even late fall.

Third, did you repot it? It is not generally a good idea to repot these except when they are making new roots in the spring. They generally only make roots once a year. If you repot after that period, you will damage the roots, and the plant will need to survive until the next spring, or until it makes new growth this season. If it came bare-root, you of course had to repot. I would not repot one of these until the following spring, no matter how bad the old media looks. Others here may have different ideas.

Some growers in Hawaii or overseas keep these very warm and watered all winter. In this circumstance they don't drop their leaves at the usual time. Or it might recently have been imported from a hot climate.

I would continue to water and fertilize heavily, in the hope it will make more new growths. This is very possible. Many people who grow these in a smaller pot, like you are, stand them in dishes of water. The plants often suck up all the water every day.

[MJG]

I will spray for spider mites.

I ordered this from Orchids Limited. Their website did say that they can grow these year-round in their conditions, without a dormancy period. That's why I am so confused about where it is in its growth cycle.

I did repot it when I got it. I wanted to look at the roots. It had a lot of long healthy-looking roots. I tried not to disturb them.

I have it potted in a mixture of bark mix and sphagnum. I water and fertilize it every 3-4 days. Any more frequently and it would stay wet.

[hypostatic]

The bulb is nice and beefy, so it was definitely being well cared for at the nursery. Right now is when you should be heavily watering and fertilizing. If you're drying it out, you could be forcing it to go dormant.

Around now would also be when this plant would start to throw out spikes in my experience -- at the end of the growth cycle, right before entering dormancy.

As opposed to other orchids, you typically don't want to disturb catasetum roots in the middle of the growth cycle. The best time to do this would be in the middle of dormancy when the media is bone dry, or right as new growth buds/roots are appearing. Disturbing the plant at the wrong time can disrupt flowering.

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With the updated information, I would continue watering and fertilizing heavily. It might make more new growths. If you go to Sunset Valley Orchids you can find cultivation information for this kind of plant. If you sign up for Fred's newsletter you will get periodic E-mails telling you how to take care of your Catasetums during that season.

Note that a lot of people across the US have plants that are very delayed compared to most years. Some people do not yet have plants ready to water at all. Tonight at our meeting a number of people said their Catasetums are still not ready to water. Yours is.

[isurus79]

I agree with everything said above.

Originally Posted by MJG

I have it potted in a mixture of bark mix and sphagnum. I water and fertilize it every 3-4 days. Any more frequently and it would stay wet.

FYI- My plant's roots don't dry out from the day I start watering to the day I start backing off to initiate dormancy. When actively growing, they want lots of moisture. Otherwise, they go to sleep!

[MJG]

Update on this orchid. I have been growing it in an air-conditioned house under lights since I got it. I had been watering and fertilizing as frequently as I could without the roots being sodden (about every 3-4 days). I was slowly losing one leaf after another.

A week and a half ago I decided it might be better off growing outside. Our temperatures are in the mid-80s during the days and 60s overnight. I figured it would like the higher heat and airflow. Also the outdoor conditions would let me water more often. It sits on a table in a portico that it shaded. It gets some direct sun starting at about 6pm as the sun begins getting lower.

I have never let this orchid dry out from the day I got it (late April/early May), fully leafed out. Since I've had this orchid, there hasn't been any new growth at all. No new leaves, and no signs on any flower spikes.

You can see now that the leaves are dropping en masse. I have only 2 leaves left that haven't started yellowing. I'm convinced that they too will be gone by next week.

So, this is my first catasetum, and this has turned out to be an experiment. What works and what doesn't. (Or maybe what doesn't work and what doesn't).

I'm wondering what I do with it now. Should i treat it as heading for dormancy when it's lost its last leaf? Why did the leaf drop accelerate so much when i moved it outside?

[hypostatic]

I think once it's started to go into dormancy, there's nothing really that you can do to reverse the course.

The good news is that the current bulb looks very healthy and plump. I would plan for dormancy starting soon, and you can gradually stop watering. Once all the leaves fall off, you won't need to start watering again until the new root growth is about 4 inches long. You should only water during dormancy if the bulb gets shriveled.

[isurus79]

Originally Posted by hypostatic

I think once it's started to go into dormancy, there's nothing really that you can do to reverse the course.

The good news is that the current bulb looks very healthy and plump. I would plan for dormancy starting soon, and you can gradually stop watering. Once all the leaves fall off, you won't need to start watering again until the new root growth is about 4 inches long. You should only water during dormancy if the bulb gets shriveled.

I agree.

I'd leave it outside and only let it get watered by nature. You might get a new growth in a few weeks.

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Originally Posted by MJG

You can see now that the leaves are dropping en masse. I have only 2 leaves left that haven't started yellowing. I'm convinced that they too will be gone by next week.

Most people's houses are a lot cooler than these like, especially at night. That might have initiated leaf drop that showed up later.

And, very important... whenever Catasetinae have unexpected yellow leaves, you need to check for spider mites. Run a tissue you press under the leaves from stem to tip. If you see brown or red streaks it has spider mites. Treat by spraying the whole plant, all surfaces, with 1 tsp / 5ml of liquid dish detergent in 1 quart / liter of water.