Finally: Disa uniflora flowers!

[Ray]

FWIW, Ed Merkle was successful with disas (in Tennessee) when he kept the pots of extremely open medium constantly moist by standing them in water that had been circulated through a refrigerator. While the cold was an important part, it really believe the circulation of the water was, too.

Moving water tends to be more oxygenated than stagnant water, and that is likely why the constant wet aspect wasn't a problem, as it might be in a relatively dense medium, just sitting in a tray of water.

[Tindomul]

Has anyone tried these in Semi-Hydro? They sound like good candidates to me.

[King_of_orchid_growing:)]

I have not personally tried using semi-hydroponics. My concern is that the result would be the same as when I tried growing them in net pots with their roots in aerated water. Like I said, the roots looked excellent, but the vegetative portion of the plants disintegrated.

If I'm gonna go high-tech, I'd actually try aeroponics.

They do not really sit in pockets of water for extended periods of time.

Flooding of the stream banks are temporary events. Flood waters eventually subside within a few days. I do not think the roots actually sit in large bodies of permanent pools of water. They are around areas where the water is moving.

[naoki]

Tindo, did you take a look at this thesis? There is a pdf download button at the left bottom.
A study of greenhouse production techniques for evergreen disas
There are a couple research done with regard to Disa cultivation. I seemed to have lost your email (I can't find it). If you PM me your email, you can take a look at those.

Like Philip said, it is easy to flower them if you get near blooming size plants. But I can't get them go to the next year. I have used a DIY ebb-flow system (a link to my blog post), so the air in the pots gets exchanged well. But I think the key is the cool root. It is fairly cool in Alaska, but they still suffer in the summer time.

I also wonder if one of the problem for me is the lack of photoperiod since I grow them indoor.

[King_of_orchid_growing:)]

From my observations of growing a few Disa uniflora, I can say the following...

These plants are short lived perennials. The mother plants die a few months after blooming, (somewhere around 2 - 3 months afterwards it seems). They do not appear to persist the way that many of the epiphytic orchids do. The only thing that persists are the new tuberoids they drop or any plantlets that have grown out from the mother plant.

The lifespan of a single plant is on the order of around 3 years.

If your Disa uniflora has initiated a spike, I do not recommend removing the spike to have the plant conserve its energy. It is more than likely that the plant has already pooled most of its energy into producing the spike/buds/flowers that it is more often than not a waste of time and a waste of flowers to remove them in the hopes that you will save the mother plant. If anyone growing Disas do end up removing the spike hoping that it will help conserve the mother plant, be prepared to be extremely disappointed because the odds are most likely in favor of not being able to see flowers, (because you got rid of the buds), and having the mother plant still die back anyways.

Naoki, that is an interesting thesis paper! It confirms a few things that I have noticed about Disa uniflora. One particular detail is that they have determined that the ambient air temperatures that Disa uniflora experience are 15 C - 28 C during the summer. This corroborates the temperature ranges I have observed them doing well in. Another one of the things that struck me was how the Disa uniflora hybrids responded really well to drip irrigation. This corresponds to how they grow in the wild the most.

Now knowing that Disa uniflora and hybrids respond the best to drip irrigation, either this or aeroponics seems to be the methods to use if you were going to go high-tech.

[King_of_orchid_growing:)]

Reading more of the thesis paper, I would have to agree with the fact that high summer night temperatures are very damaging to Disa uniflora. Luckily I have found that they respond very well to being put in the refrigerator at a temperature of about 36 F to 45 F. You will get wilted plants that perk back up in a day or two without any further assistance on your part.

They do not respond well to being grown in decomposed granite or fine sand.

Do not use any kind of clay you can get your hands on as a potting medium! There are many kinds of "clay". The most commonly sold "clay" is kaolinite which contains a higher concentration of calcium carbonate than other kinds of clay.

When I talk about clay minerals, I am not referring to any kind of clay! I am talking specifically about stuff like the plagioclase or orthoclase in the rocks they grow in. That is what things like plagioclase or orthoclase are technically called in pedology when they get weathered out of the rocks. This is why people get confused when I'm talking about this stuff.

The following links should help clear things up a little bit:

https://flexiblelearning.auckland.ac...agioclase.html

https://flexiblelearning.auckland.ac...rthoclase.html

The weathered plagioclase or orthoclase is what they are feeding on in the wild. The soils they come from are not "nutrient poor". There are plenty of nutrients for the plants to feed on. If the soils were truly nutrient poor, there'd be nothing growing there. The nutrients are being weathered out of the rocks or are leaching out of the rocks in trace quantities. In our hobby, we should discontinue using that confusing term "nutrient poor". It makes some people have the false impression that the plants should not be fertilized or makes them think to fertilize too little. One of the biggest problems with growing Disas aside from root rot from too much water is actually nutrient deficiency.

Yes, they do have a seasonal growth pattern with different parts of the plant growing at different times of the year.

I can agree that spring is the most active growing period with roots and shoots growing quickly.

Late fall through winter is definitely very quiet in terms of growth.

Since, for me, summer has always been the time of the year that has been problematic, I cannot give personal accounts of what happens with the plants in terms of growth. I can currently only tell you about the pitfalls that people can fall into during the summer months and maybe provide some solutions that work to some of those problems from firsthand experience.

[Tindomul]

Great info, thank you!

[DocDee]

Some years back I observed D. uniflora flowering in its natural habitat. This was on the Eastern portion of Table Mountain at an elevation of about 3000 ft. This was in February (late summer). The winter there is very wet and the summer is dry and hot, so perennial water is not commonplace. It seeps out of the sandstone into drainage gullies where the disas are typically found.


Location link:
Google maps location

View of the sort of 'river banks' where it grows. Shallow, cool, slow, lots of tannin. Disa is usually found in small trench-like gullies with steep sandstone walls which provide shelter from wind and excessive sun.
Google street view

[estación seca]

DocDee, Welcome to the Orchid Board!

Thank you for the information - it helps a lot getting an idea of how they grow in habitat.