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Beautiful flowers, Mike!

Beautiful M. hermosana specimens, I like the clear white spines. On mine immature plants spines are more beige than white.

Nino_G wrote: ↑Thu Oct 26, 2023 4:03 pm Beautiful M. hermosana specimens, I like the clear white spines. On mine immature plants spines are more beige than white.

Yes they do vary a bit. Most are not white but beige as you say, or even pinkish. A very nice species. I have some breviplumosa seeds to plant in the next few weeks too...

Mamm herrerae
Mamm pectinifera
Reb perplexa
Mamm marksiana
Mamm Lauii fma dasyacantha
Mamm solicioides
Mamm ''carmenae'' red sp.
Heliocereus specious var. amacamensis First flower from seedling.
Noto uebelmannianus
Ehcinocereus ''ctenoides''
Sulc. areancea
Sulc. rauschii
Lob. densispina group
Lob. densispina group.

Some recent bloomings

Love the giant thelocactus flowers

I decided to (finally) repot my large Notocactus warasii. Last time was maybe 6 years ago. The top of the mix in the pot had become rock hard and matted with roots.


If terra cotta pots are used, I line the inside with plastic...

The new pot is also terra cotta but it has a semi glaze on the outside and water/air does not penetrate so no lining will be necessary


A bit of mesh over the hole to stop stuff falling out...


The bottom of the pot was covered with about 1 inch of this size scoria..


Then some smaller ( about 5mm ) sized particles of the same material.


The mix is a simple combination of composted pinebark, quartz gravel and scoria all between 3 and 5mm in size. (The pinebark is sifted from commercial potting mix and has all trace elements added = some N and some P. K is naturally in the bark. Lime is added to bring the pH to about 6.5) I add about 1gram per litre of FeSo4 to help counter the alkalinity of the scoria and supply more Iron for this South American species.

Once out of the pot I find matted roots which grew behind the plastic, long old roots and many oxalis bulbs so more soil than I wanted was taken off
because I had to cut off quite a bit of root, the pot was now way too big. I could get a smaller one or I could effectively reduce the volume if the pot by adding some inert material which just takes up space. In this case... chunks of polystyrene placed over some potting mix...



Then make a mound of the mix....

...And place the cactus with trimmed roots on top and adjust the position tilt and height....


I added more mix and styrene chunks...


To this size pot I add about this much gypsum to the top of the mix


This probably it's best side at the moment. I won't bother to add any fertilizer this season as it will take a good month to establish and there will be enough in the mix for that. It should start moving next year when I will give it a handful of osmocote. The dust washed of but not watered. I will water it in about 2 weeks I guess but lightly spray it once a day.

Excellent post Mike, thank you for your effort. May I ask why did you replace part of the substrate volume with styrofoam? To speed up drying?
Best regards,
Nino

I'm wondering why you put the layer of Scoria on the bottom to begin with? Pot too deep and didn't have a shallower one?

Have you ever used a clay pot sealer? The one I've been using is a spray can of clear sealer. Kind of like a varnish. It has a lot of solvent: acetone, toluene, and the sealer is probably the acetates. I have not seen the results on the plants yet since I've only started using it last summer.

Nino_G wrote: ↑Mon Jan 29, 2024 1:12 pm May I ask why did you replace part of the substrate volume with styrofoam? To speed up drying?

Yes to help it dry out faster. Too much unused mix is no good.

jerrytheplater post_id=405190 time=1706547152 user_id=17692]
I'm wondering why you put the layer of Scoria on the bottom to begin with? Pot too deep and didn't have a shallower one?

Hi Jerry. I do that so when the roots hit the bottom of the pot they do not find a saturated, airless layer but a well aerated and just-moist one. This is common practice in Japan where they are experts at potting. It has nothing to do with drainage even though they call it a drainage layer. It also allows more heavy watering so is more forgiving. I thought this pot was a good visual fit for the specimen.

Have you ever used a clay pot sealer? The one I've been using is a spray can of clear sealer. Kind of like a varnish. It has a lot of solvent: acetone, toluene, and the sealer is probably the acetates. I have not seen the results on the plants yet since I've only started using it last summer.

Yes I have used pot sealers many times. It was not necessary on this one. From memory, the sealers were not available when I last potted this plant. I recommend you spray just the outside of the pot and perhaps an inch on the inside. If you look at glazed bonsai pots you will find they are never glazed on the inside. For some reason the roots don't seen to do as well with it. Possibly they are just more stable without a glaze?