The future of Disas in cultivation, pics!

[estación seca]

I haven't grow either due to inability to provide correct conditions, but it always seemed to me the Disas from streamsides need very similar conditions to Darlingtonia californica.

[Ray]

I guess some of it is based upon how you define "stress."

Using a human analogy, overweight due to overeating and drinking certainly makes one comfortable, but places undue stresses on the cardiovascular system. Sure, plants don't react like animals, but nutrient pressure is still stress in my book.

Plants - especially orchids - are "niche plants," so have evolved with very specific cultural parameters. Move them out of that in any way, and you're stressing it, in my book.

[meizzwang]

Ray: that's an outstanding insight, thanks for sharing! Learning a ton from this discussion, and such facts really make you think. You're absolutely right on a very technical level, but this isn't the point of the discussion. The point might seem counter-intuitive : how do we manipulate cultural practices and push the plants out of their very strict cultural parameters to increase their long term success in cultivation?


Estacion Seca: I had darlingtonia growing side by side with the Disas, and every last Darlingtonia died during a heat wave a few years ago, whereas some of the disas survived. This leads me to believe that Disas are more cultivation friendly relatively speaking.

[meizzwang]

some seedlings, lost quite a few and I hope these hold on. I think this is supposed to be the yellow variant of D. uniflora! Photos taken 4/3/17:



Here are the main plants now under 75% shade cloth. We've been having sunny days near 80F recently, so even morning sun can get too hot for them:

[King_of_orchid_growing:)]

Originally Posted by meizzwang

...every last Darlingtonia died during a heat wave a few years ago, whereas some of the disas survived. This leads me to believe that Disas are more cultivation friendly relatively speaking.

From personal experience, Disa uniflora are tolerant of heat up to 85 F to 90 F. Beyond this range of heat, it can be problematic for them. Due to the reason they come from South Africa, (which is generally considered an area that would be classified as either a savannah or a semi-arid desert such as places like Southern California), heat IS commonplace, and therefore, a species such as Disa uniflora has a fair degree of heat tolerance.

The caveat would be that because they are quite prevalent in the Table Mountain area of Cape Town, South Africa, (at least the red varieties are), and due to the high elevation of the region, as well as its close proximity to the coastline, the amount of heat a species such as Disa uniflora can tolerate is limited by degree as well as by duration, but it is difficult to specify details on this matter at the moment unless I keep meticulous records.

With that said, I have not noticed whether the temperatures here have risen up to 116 F before, but it is not impossible. I also have not taken notice nor have kept track of how long temperatures here stay above 100 F. I have noticed that most of the times, it does approach 90 F to 100 F here, with some days reaching temperatures over 100 F. I cannot say with any certainty or confidence as to whether or not a species such as Disa uniflora would be able to tolerate temperatures in excess of 100 F over a long duration of time, although it is a good bet to say that they will suffer. So this is definitely consistent and in line with what the original poster had mentioned about her own plants dying off in large numbers during a heatwave where she lives.

Do understand that although I live in the Los Angeles County area, I do not live near the coast. So, when I'm speaking about growing Disas, I am talking from the experience of having to grow them approximately 27 to 28 miles inland from the coast. I do not have the benefit of coastal breezes to cool things down or to curb the heat during the summer.

Aside from that, if anyone is interested in knowing for the purposes of further context, Table Mountain itself is reported to be 3,558 ft tall.

Other plants that are in this area are species such as:

Crassula coccinea - (a succulent)
Fire Heath (Erica cerinthoides)
Yellow Rice Heath (Erica lutea)
Coat-hanger Heath (Erica plukenetii)
King Protea (Protea cynaroides)
Saltera sarcocolla - (a succulent leafed shrub belonging to the family Penaeaceae)
Tritoniopsis triticea - (a flower that is in the Iris family)

As a side note, I may have seen either Tritoniopsis caffra or Tritoniopsis triticea offered for sale as a bulb from time-to-time in various nurseries in the Los Angeles County areas.

According to Encyclopedia Brittanica, the summit of Table Mountain experiences around 60 inches of rain a year, while the base of Table Mountain experiences around 22 inches of rain a year.

[estación seca]

Disa uniflora and Darlingtonia californica grow in or next to frigid snow runoff streams. The air temperature isn't nearly as important as the root/rhizome temperature.

[King_of_orchid_growing:)]

Originally Posted by estación seca

Disa uniflora and Darlingtonia californica grow in or next to frigid snow runoff streams.

I am not an avid collector/grower of carnivorous plants. That is a skill I didn't delve into in any great depth. So I cannot make any kind of meaningful comparisons between Darlingtonia californica, (aka California Pitcher Plant, Cobra Lily, Cobra Plant), and Disa uniflora.

However, I will say that Disa uniflora does not always grow in or next to frigid snow runoff streams. It is not to say that they do not ever grow in areas that do get frigid, because the truth of the matter is, some groups of individuals do. But they are not restricted to these areas.

Originally Posted by estación seca

The air temperature isn't nearly as important as the root/rhizome temperature.

Again, I don't know much about carnivorous plants such as Darlingtonia californica, but I can say that rhizome/root temperatures for Disa uniflora does appear to be a bit more important than the ambient air temperature the leaves experience. While I believe it could be slightly advantageous to water Disa uniflora with refrigerated water, I have not found any strong evidence via my personal experiences to suggest that it is of significant benefit in order to successfully get them to thrive. There appears to be other factors that are far more important to Disa uniflora than the temperature of the water or root zone.

[estación seca]

I have not been to Disa uniflora habitat, but I know quite a few people who have been. I have been given advice on how to grow it by South Africans. I looked into growing it and studied up on it quite a bit. That is why I don't try to grow it: Right now I can't meet its needs.

Disa uniflora is a semi-aquatic plant. It does not grow at any distance away from water to any significant extent. It grows in or beside cold streams.
Disa uniflora

The cold water keeps the plant cool, even when air temperatures rise. Keeping the roots cool is more important than controlling the air temperature.

It grows in the winter-rainfall region of South Africa. This region has cool and wet winters. Summers are dry and warm. The only reason Disa uniflora can grow and bloom during the warm, dry summer is because it is growing in water.

People cultivating them in hot climates lose them during hot spells. If these gardeners were able to keep the roots cool this would not be as much of an issue. The link I gave above, from Kirstenbosch, also gives detailed cultivation information. Note the comments on temperature and that they are said to grow best in partial shade.

This is not a carnivorous plant forum, but some successful Darlingtonia growers do, indeed use chilled water for their plants. Some also use to-and-fro water systems. If you go to CP forums you can read how they do it. These methods should work with Disa as well.

[meizzwang]

I suspect Disas can tolerate summer heat, even soil temps that go above 80F temporarily, only under certain stages of their growth cycle. during the heat of summer and fall when the plants have bloomed out and pretty much died and are in the process of being replaced by side shoots or stolons, growth is very slow. At this stage, the plants seem to be able to tolerate more heat than when they are in active growth (ie. late fall thru the spring).

Again, this ability to tolerate heat is completely dependent upon receiving cool nights. Without those cool nights, these plants will rot eventually.

some more pics! I have another pot of D. Glasgow Orchid conference opening up, while the rest of the plants are either in spike or not even showing signs of flowering yet! It's strange: some plants are abnormally early, a few are on time, and most are late. We usually get most of the plants to bloom around early June thru July here in Northern California:

[King_of_orchid_growing:)]

Disa uniflora tends to bloom down here in Southern California at right around the same time frame as yours do up in Northern California. Typically, I've noticed the blooms come out around late May to mid-June. I don't believe I've ever seen any of the ones I've grown to have bloomed in July, though. I guess there's a lot of individual variation in the species regarding bloom times.