So I decided to sow

[iann]

Delosperma bosseranum might want more water. These things are barely succulent at all. Or at least they are succulent, but still seem to need about as much water as a normal plant. They can go dormant to survive drought, but won't look good on it and won't grow. Also, they like it warm so I'd have thought they'd be raring to go right now. In good conditions they will grow quickly and flower prolifically, although the flowers are tiny.

Lapidaria are tough but slow. Schwantesia are similar, the first leaves can take months to come through. They'll get there. Mine grow and flower all summer, but maybe they will take a break for you when it gets very hot.

Yes, very few mesembs are killed by underwatering, mostly by overwatering. Especially by overwatering when they are dormant. I find the ones that go completely dead-looking in summer much safer because I'm less tempted to water them. Things that stay green but should be left dry, I'm likely to water and kill. Monilar go totally dead-looking and should be left entirely dry at that time. They can be shaded but are really pretty tough in that state. In their first year, I'd keep watering until the leaves give up, then leave it dry until it starts to cool down after summer. I'm not sure how you'll do with this. They grow best with night-time temperatures below 10C and I don't think that gives you much of a growing season!

[mmcavall]

thanks again Iann, fully understood.
I feel like I had a tutor (or many tutors) on the other side of the world taking care of my plants.

summer is coming...

[mmcavall]

Here are some results with cacti, batches from 30, 21 and 15 days ago.

Most of the seeds are from a grower I don’t really know very well. Some of his seeds germinated, some not, most striking was the “cactus mix”, with 0% germination.

Some of the seeds are Aiko’s: the Astro mix, with high percentage of germination, and the Notocactus magnificus (only 15% sprouted, but I believe the low rate is due to my method).

I did not used the baggie method, because it is too warm and I don’t feel comfortable to let the seedlings in closed pots…I feel like cooking the seedlings. Even spraying water twice a day, and being sure that the substrate never dried out, this method may have accounted for low germination rates of some (more difficult?) species.

Moreover, I probably did not regulate very well the sunlight, and some seedlings may be sun stressed or even died.

Some of the Astro died, leaving an empty involucre or sac…too wet? too dry?

The statistics:

Species sowed 30 days ago:
Notocactus leninghausii = 0%
Notocactus mammulosus = 20%
Notocactus submammulosus =30%
Notocactus turececkianus =60%
Rebutia pygmaea = 20%
Lobivia aurea =20%
Lobivia haematantha var. corrugata = 0%
Lobivia pentlandii = 0%
Soehrensia bruchii = 15%
Soehrensia formosa = 55%
Echinocereus fitchii = 80%
Cactus mix = 0%

Species sowed 21 days ago:
Astrophytum mix = 70%
Notocactus magnificus = 15%
Cactus mix = 0%

Species sowed 15 days ago:
Astrophytum capricorne = 30%
The following species were sowed in a manner to save pots, substrate and shelf space, which is: two species per pot, so I can’t say of which species are the seedlings (sowed 15 days ago), ad percentages are approximates:
Acanthocalycium spiniflorum + Gymnocalycium mazanense =30%
Trichocereus andalgalensis + Gymnocalycium quehlianum = 25%
Trichocereus huascha + Gymnocalycium schickendantzii = 0%
Trichocereus pseudocandicans + Gymnocalycium spegazzinii = 70%


You people can see the (not very good) pictures and tell me whether the seedlings are healthy, sun stressed, etc

Notocactus mammulosus:


Notocactus turececkianus


Notocactus submammulosus


Astrophytum mix:


Echinocereus fitchii


Astrophytum capricorne


Soehrensia formosa





Notocactus magnificus


Lobivia aurea


Acanthocalycium spiniflorum + Gymnocalycium mazanense:


Trichocereus andalgalensis + Gymnocalycium quehlianum

[iann]

I'd give them more shade. At least for a while. Some, like the Echinocereus, will quickly be able to take the sun but too much too early will set them back.

[mmcavall]

Thanks again Iann. I've shaded everybody a little more. They look happy and I feel more secure, but...

...now I'm experiencing some problems with the Astro seedlings. Anyone interested in please see the thread "Astro seedlings sudden death":

http://www.cactiguide.com/forum/viewtop ... 16&t=37924" onclick="window.open(this.href);return false;

[mmcavall]

Proud of having controled my OCD and have left the Mesembs seelings without water for 4 complete days.
It was nice to see they happy and turgid in a completely dry substrate.
Aiming to reach 10 days soon. Hope this is the wright way to grow this plants.

[Wilk]

I got rather concerned when my Mesembs got leggy and very thin stemmed. I was convinced the stems would just wither and die. In fact that did not happen at all. They all survived more or less.

[mmcavall]

Do you guys think that using silver shade cloth above the cacti seedlings shelf would help?

I use a black one, but I heard that silver clothes reflects part of the UV light back to space (while black ones do not). If this is true, using a silver shade cloth would allow good light without the nocive UV rays...

Have someone tested different shade clothes colors to protect the seedlings?

[iaeen]

The plants receive the light that passes through the gaps in the cloth, so the color of the cloth makes no difference there.

The difference will be what happens to the light that hits the cloth. Black cloth is black because it absorbs most of the visible light (and probably in the UV/IR spectrums as well) that hits it. The energy from those photons has to go somewhere, so it is converted into heat. White cloth OTOH, reflects most of the light that hits it, so those photons wouldn't be turned into heat on until they do hit some material able to absorb them.

Personally, I doubt that it makes that much of a difference. If you are really concerned about excessive heat in your greenhouse, you could always put the cloth on the outside of your greenhouse.

[mmcavall]

Thanks Iaeen for replying.

I believe that the part of the light that do not pass directly through the gaps and is also not reflected, i.e., the part that hits the shade cloth and suffer from refraction, may spread in many directions, causing a difuse radiation under the shade cloth, which may have some effect to the plants below, and may be diferent according to the color of the shade cloth.
I'm curious about the effects of light spectrum, light diffusion (which may differ according to the shade cloth) and its effects on the light-sensible cacti seedlings. But, as you said, it is possible that it makes not a great difference.

I'll try anyway because heat is a concern to the Mesembs seedlings and any degree I could diminish would be a gain. Let's see what will happen.

[mmcavall]

I’m satisfied with the development of the Mesembs in my hot climate. Summer is coming and I don’t know how will it affect the Mesembs, but, for now, they look fine and I begin to have some hope that I will succeed cultivating them here.

I put a new (silver) shade cloth to protect the seedlings…



… but it in fact did not helped to decrease temperature: no significant differences were observed.

Light under this shade cloth is “lighter” than under black shade cloth; I’m satisfied with the general aspect of plants and lightening:



Most of the Mesembs are doing fine, except for Lapidaria, which disappeared from the pot. Monilaria is still with leaves. The (until now) slow Tanquana is showing a renewed vigor now. The others are great.

I begin to understand that they would not like to be disturbed/reppoted for a long long time, and that they prefer to stay quiet in their places without too much expectation on them, which means I must slowly but definitely diminish water supply.

Here are the pictures of the plants at 60 days after sowing:

Tanquana prismatica is showing up:


As well as the Schwantesia loeschiana




Monilaria is still with leaves:


Delospermas:




Glottiphyllums:




Pleiospilus:













Cerochlamys pachyphylla:


Nananthus wilmaniae:


Schwantesia herrei:

[mmcavall]

wrong movement: yesterday I watered the Mesembs, a good soak. Today is cloudy, possibly it will rain...I hope pots dry out quickly...

[mmcavall]

I have to admit: I did want to believe that cacti seedlings are so sensible to sunlight, and this cost me some/many seedlings… After following some threads here and comparing the colors of the plants, I decided to give some more shade to them. Now I added white paper over part of the cacti seedlings.

Until now, however, they were under 4 layers of shade cloth, one black and 3 silvery, which I believed was more than enough (I sowed some dragon fruit seeds in January and let they grow under full sun, where they are until now. They are fine. I forget to take a picture to show here. But this and other previous experiences with Melocactus made me believe that they could grow under a considerable amount of sunlight!).

Anyway, when it is not working, it is time to admit your errors and try to fix them.

The cacti seedlings are inside those wood boxes you can see in the lower shelf; over the shelf you can see the shade clothes:



A closer look showing the additional shading provided by white paper sheets:



That’s a general view of the seedlings’ shelf. Two wood boxes without paper covering, them the wood box with paper covering (where I have just put most of the cacti seedlings), and them the white plastic box, where the 60 days old Mesembs are:



For comparison, these Mesembs are under a single layer of silver shade cloth, while cacti have four, plus the new white sheet of paper! You can see the Mesembs in the white plastic box in the pictures above.

As I have many Astro seedlings, I put one trail under the white paper shade, and another out of the paper shade (in the first wood box in the picture), for comparison.

Let’s give some weeks to them and see how they will respond.

[Pushrestart]

Anyway, when it is not working, it is time to admit your errors and try to fix them.

This has to be the best advice to anyone who wants to grow well- keep on trying, experimenting, etc
Mesembs most of them as I understand it, they dont mind getting lots of sun once they've germinated- not full sun, but lots of it. You're in Brazil so I would imagine that the sun there is very intense all year round, right?
Cactus -generally- seem to like more shade, warmth, high humidity for longer periods of time, a cushy lifestyle for a bit . It'll be interesting to see how your experiment with the astros works out.

Also how lucky are you that you live and grow in Brazil ! Rupiculous laelias from the mountains of Minhas Gerais are one of my absolute favorites, they are what led me to succulent plants. Cheers.

[mmcavall]

Thanks Pushrestart for your comments and for following this thread. Sure I'll post the results of my experiments here.

Indeed, even in the southeast Brazil, where I live, sun is very intense all year round, and it probably makes a huge difference for plants in relation to sun intensity in England or northern USA, places where many of the members of this forum are from; as a result, for me it is dificult to calibrate the information about caring. I usualy tend to consider the advices too exaggerate, as if the plants were the most fragile things in the world, while I consider then usually very strong. But the truth is here we have much more room for errors. Not so good conditions will not kill the plants, they keep going anyway... As I told above, I succeed in growing Melocactus from seed without any concern about lightening/shading or humidity. That's why I took a long time to admit I was wrong in giveing the cacti a not good shade. Not easy to calibrate what is "strong sun" or "light shade" when said by someone from Sweeden, for example! Anyway, without the advices of people here, I probably would'nt succeed in germinating the Mesembs, that are from a particular climate which is quite different from mine. And I'm still counting on the forum to succeed in keep then alive during the summer and so on...

Indeed, Minas Gerais is incredible. Do you have been here? The Laelias, but also the Sophronitis, I believe all included in Cattleya now, are spetacular. And the cacti and the Bromeliads from there, genus such as Dyckia, Encholirium, Ortophytum...In my Master Degree I studied the population genetic structure of Encholirium species in the mountains of Minas Gerais. You can see some pictures in my Flickr galery. They are not very good because they were digitalized from original paper photos. But in this picture here you can see some rupiculous Laelia among some crazy Araceae, and you can keep navigating to see the Encholirium:

https://www.flickr.com/photos/125458730 ... ed-public/" onclick="window.open(this.href);return false;

thanks again for following and take part in this thread