Which one will die first?

[mmcavall]

Ok, maybe I'll not let them die, but almost...
This is an experiment I'm doing, just to learn a little more about my plants.

The plants inside the wood box will not receive water until....I dont know exactly...I just want to see how they will respond to this, how many time will pass till they became really near death.







The experiment started November 18th, so it passed almost a month. The first to show signs of dehydratation was Portulacaria afra, and maybe Crassula expansa. All other looks fine. The Huernia, in fact, looks finer than the other Huernia that are receiving water.

Plants are (some may be misidentified):

Cacti:
Mammillaria sheldonii
Echinopsis oxygona
Mammilaria vetula (M. fragilis)
NOID colunar cactus
NOID Opuntia

Crassulaceae:
Echeveria "black prince"
Echeveria "Perle von Nurnberg"
Echeveria "topsy turvy"
Sedum rubrotinctum
Crassula perforata
Crassula expansa
Kalanchoe tomentosa

Portulacaceae:
Portulacaria afra

Apocynaceae/Asclepiadaceae:
Huernia schneideriana
Huernia sp.

Asteraceae:
Senecio stapeliiformis

So, which one will need water first? Which one will last longer?
Place your bets!

[K.W.]

>>>

Place your bets!

[mmcavall]

(*,)

I'm not sure about the meaning/objective of this "comment". For me is more to the bad side and made me feel kind of unconfortable, but I may be wrong.

of course I'm not expecting real "bets", I was just estimulating those that may be interested in following this thread to make any guesses or comments.

For me it is an interesting thing to learn, since I use to water my plants frequently and dont know their drought resistance habilities very well.

[7george]

I think the leaf succulents will start dieing out first and the cacti will be last. The actual time for this will depend on the temperature in your GH. Now in Brazil is the rainy season, right? So you can expect first results in several months I think. My bet to be the last is for Mammillaria sheldonii, but you should patient more then 1 year for that.

[mmcavall]

Thanks George for your reply. Yes, it is the rainy season now, until Mars. Last week, it rained every single day. But all my plants are protected, inside the greenhouse, under plastic cover. No rain falls over the plants. When the sun is shinning, temperatures go to 35C (95F). I agree with you, the cacti will last longer. I noticed that Senecio is already less turgid.

[kristian_Fossmo]

The spherical mammillaria for sure, optimum area to volume ratio . My M. Hanihana has not been given water for three months now, in the beginning they shrunk maybe 25% of the radius, then they enabled survive mode and has not shrunken more, what my eyes can detect anyway... The big one are maybe 2,5 cm wide and 4 cm high.

[eduart]

Well, I wouldn't get a kitties, puppies and the random frog or amphibian and keep them without water just to see who's becoming first really near dead... Aren't plants living beings as well?

[mmcavall]

Well, I wouldn't get a kitties, puppies and the random frog or amphibian and keep them without water just to see who's becoming first really near dead... Aren't plants living beings as well?

Seriously?

I'm just trying to simulate their natural habitat and learn a little from that.

As I said, I use to water the plants very frequently, probably too much for succulents.

(by the way, Kristian: I've never let a Mammilaria without water for more than 10 days. Three months would be a super record)

But ok, so let's change the experiment a little: I'll water the plants in January 18th, i.e. they will be dry only for two months. This is far more than I have ever did. And this is certainly much less than they would experience if they were in their natural habitats.

[iann]

I bet you water before me My bet would be the leafy succulents like the Portulacra will look pretty bad after a few weeks without water. Echeverias too probably won't be happy. I don't think you'll kill any of them with two or even three months lack of water, but maybe it won't be pretty,

[eduart]

You could learn from mistakes (yours or others), but trying to kill them on purpose?

[mmcavall]

Until now, only the Portulaca, Echeveria black prince and Crassula expansa looks thirsty and I may water then soon, not need to go further. The others look fine. Huernia is in bloom.

[KimKactus]

So? Did you water? It's January 18th!!!

[Nic]

I sorta hope he didn't, going without water is the whole point of the experiment.

[mmcavall]

Hi KimKactus and Nic, thanks for asking. I did not know that there was somebody interested.

In fact I watered the plants in January 7th, i.e., 50 days after the experiment begins. I couldn’t wait more 10 days until 18th, because of the Crassula perforata: it was looking very bad. I could have rescued this single plant and continue with the others, but I choose a different approach.

I'll continue the experiment with increasing periods of drought; the less tolerant plants will be "rescued" out of the game (to a regularly-watered shelf) according to their responses to drought stress. Next watering ~Mars 15th (65 days) and them we enter Fall and Winter, were dry periods can be longer, maybe 90 and 120 days.

Results until now:

The first to get out was in fact Portulacaria afra. It was taken out of the experiment before the 50th day (but I forgot to write down the exact day; it was before Christmas for sure).

For the next cicle (65 days), probably Crassula perforata will not take part (however, when I watered the plants in January 7th, it recovered very quickly and the day after it was looking very good, as if the stress had never happened; so I may keep it in the next cycle).

At the 50th day, some of the other plants were also looking bad, but they would survive more 10 or 15 days without water for sure.
Here is the approximate “rank”, from the less tolerant to the more (kind of a subjective evaluation), with some pictures taken just before watering:
1- Portulacaria afra (no pictures)
2- Crassula perforata: serioulsy dehidrated, not sure it would resist for more 10 days


3- Crassula expansa: very dehidrated, but far from dyeing; it recovered very fast and nicely after watering


4- Senecio stapeliiformis: it is thirstier than I have imagined; the stem became very withered;
(no pictures)
5- Echeveria Black Prince: the outer leaves were very dehydrated


6- Opuntia cf. robusta Monstrose: it was surprising (to me) shrunk (please correct my English, it is hard to find the correct term


7- Echeveria "topsy turvy": the outer leaves were dehydrated, but the inner ones were stout


8- Echeveria sp (probably wrongly identified as Perle von Nurberg): despite its bad looking in the beginning of the experiment, this plant resisted the 50 days and did not seem to be seriously stressed;


9- Sedum rubrotinctum: only the lower leaves seem to be a little stressed, but the plant is healthy and could stand for some weeks more without water



10- Huernias: they are amazing! The short stems were kept turgid, and they bloomed more than once. The long stem of one of the plants was drained to supply the shorter ones (as one can see in the picture); however, about two days after watering, this long stem was erect again;






11 - Mammillaria cf. sheldonii, M. vetula/gracilis, Echinopis oxygona (no pics.) and the NOID columnar cactus (no pics.) did not displayed any sign of stress, however, no sign of growth as well;





12- Kalanchoe tomentosa: this plant managed to grow a new leaf, keeping all others unaltered.

[Nic]

That is a good idea too, it will show which is toughest over the long run.