I cover my gree houses with 50% shadecloth from mid of November to the end of March every year. I finished the covering this morning.
I found quite many cactus were in bloom under soft sunlight this evening.
The followings 3 photos are some of asterias cultivars, bloomimg this evening.
asterias cv hanazono kabuto

asterias cv super kabuto

asterias cv Iwata dai-now kabuto

Just beautiful

Beautiful.
I'm still working light levels with my house as its the first summer since i got it.
I was thinking of using shade cloth so my plants dont cook, its obviously working for you Hanazono so I might give it a go.

Do you you have any other tips to get these kind of results?

KanJe
Asterias will grow well when you feed water a lot in hot days but they are easy to rot because they have a thick taproot.
I use clear polycarbonate sheets as roof of green house. 50% white shadecloth is put up under the roof, inside of greehouse permanently.
This setting will give you a soft sunlight and hot atmosphere in your green house. In summer, SA is too hot. I put up 50% green shadecloth over the roof. This will give you further soft sunlight and cooler atmosphere in your green house. Asterias can grow through a year with this setting.
I will cut off taproot of all asterias completely when seedlings are 2 years old. No rotted out will occure even if you feed a lot of wated in hot days because plants has no taproot.
It is not natural but plants look good when it is grown quickly.

That's great Hanazono.

I also use polycarbonate for my house, do you have the 50% white shade cloth all during winter as well?

Also do you find much difference between the green and white shade cloth?

Do you cut the roots completely of the seedlings and are there any issues with the
roots growing back when they are so young?

I hope this would be useful to everyone here if we could achieve results like yours.

KanJe
50% white shadecloth in the greenhouse is permanet, including winter.
Although same 50%, green one will give softer sunlight, I think. Growth of seedlings is better when I use green one.
I cut tap root of 2 years old myriostigma and asterias in the end of August. Rooting of myriostigma will have no problem but you may lose some asterias.
It is better to cut root every year from 3 years old but you have to remain around 3 cm length. I have too many asterias and hard to do this.

I might try the 50% white shadecloth first and see how that goes. At the moment half of my astros are on the top shelf with full sun which isnt burning them but they're not exactly growing rapidly either.
I have been experimenting with zoningin the house by trying different genera on different shelves with stuff above them to block light. I still find this too inconsistent for the more slow growing varieties which take long enough just to adapt to their environment as it is.

I'll try this idea out and get back to you with some pics.

In regards to the root cutting, I might give it a go with a couple of my younger plants and see how it goes. Hopefully it saves some heartache in the future...

Thanks Hanazono, I got a lot from that.

i use 50% white shadecloth over the whole roof and sides of my greenhouse. its my first year growing in the greenhouse which was completed in early spring so i put the shade cloth on in october when i noticed that the sun was getting too strong and resulting in sunburn. in mid-late Autumn i will probably take it off.. shouldn't need it in a Melbourne winter.

Great advice about shade houses here - and how to stop astro's from rotting. Well done!