Saguaro

[Sirethar]

Hello to all!
I'm new to succulents, I have 1 mammillaria, 1 aloe, 1 euphorbia enopla, 1 euphorbia lactea and 1 pachycereus pringlei...and 4 saguaro (Carnegiea gigantea).
3 saguaro are very small... and one is bigger.
In next days i'm going to put the bigger one into a new container (not made in plastic).
Any Suggestions (especially for the smaller ones)?
I live in Northern Italy (city of Turin, the one of winter olympic games 2006). Actually i'm keeping the smaller saguaro with a morning sun only.
The other succulents are instead on my South balcony(that's much hotter).
Here the photos:

[TimN]

A bigger pot made from clay would work. Don't go too big, though.

I'd plant that large saguaro a little higher in the pot next time. With saguaro, you should be able to see the narrrow section of the stem, right above the roots. They can be a unstable until the new roots get a hold, but it will be solid once you get some root growth.

The pots for the small plants seem to be very large for the size of the plant. If you have some smaller pots, that will help the soil to dry completely between watering. Not super critical, but might be a good thing, in my opinion.

Tim

[Sirethar]

Ok, thanks!
Tomorrow i will change container for the bigger one.
What about the depth?
Do the saguaro roots require a deep container?
i ask, because i was thinking a pot like one.
Do you think that i can put the smaller ones in the south balcony (afternoon sun with 42 celsius - 100 Fahrenheit degrees in the sun).

[iann]

Saguaros develop a short stabilising taproot, plus a wide spreading fibrous root system. I say a short taproot although it can be a fair size on a big plant, it is not the sort of thing that is usually a problem in a pot. You can really cram in the roots and still grow a healthy plant. A larger pot, up to the size of the root system, will give better results (assuming you water infrequently and allow the large mass of soil to dry out thoroughly) but quickly becomes impractical due to size and weight. Growth is slow, the most important thing is not to use a pot much larger than the existing roots.

[TimN]

The smaller ones might be able to take more direct sun and heat. In habitat, they generally start out under a nurse plant and get filtered light until they are about the size of your large plant.

That said, if you keep an eye on it it shouldn't really have a problem. If it starts to scorch, use some window screen to give it some filtered light.

Once they get acclimated they should be fine. One other note, once you get them acclimated to the sun in one position, if you are going to move the plant to expose another side to the sun, you will need to acclimate the new side to the harsh sunlight.

Tim

[Sirethar]

I will leave them all in morning sun for 10 days (the time i'll be away on holiday).
When i'll be back, i'll put 'em all on south balcony position.
What about fertilizing? I have a NPK 6-5-11 for cactus.
After change of container i won't water the plant and fertilize for 2 weeks. is it ok?

[Sirethar]

Operation change container done. Sadly i damaged some roots (they went away with soil remove). But plant still have more than half roots. I'm sad for the little damage, but i have big hopes in the saguaro survive power.
I watered it 2 days ago when i bought it. today i changed container, and i'm going to not water it until 18 august, when i'll be back from seaside.
photos:

[daiv]

Don't worry, a little root damage is to be expected. That pot should be just fine for your cactus.

[TimN]

That looks great! I'm sure it will be fine. They are pretty tough once they get this big.

It looks like it's in the pot just right!

Now you just have to wait 60 years or so and you'll have flowers!

Tim

[Sirethar]

Yeah! And even more years to see an arm
Well, if i will be like my aunt (97 years) maybe i will see it flowering and growing.