The power of scoria (lava rock)

[terryros]

Lava rock around here and online is mostly for gas grills/fireplaces or for landscaping. One I just found is 18-24 mm size particles, red lava rock, $22 US for 4.5 kg! That price is typical for the weight of most things I find online. It has also not been easy to find bulk lava rock of varying sizes. Fortunately not an emergency for me so I can keep exploring.

[estación seca]

In the US lava rock / scoria is often sold in bags in the landscaping mulch section of hardware stores or garden shops. If you think it's too large, you can smash it with a hammer. Wear eye protection. I don't think the sharp edges are a problem for Phalaenopsis roots.

[Mr.Fakename]

Originally Posted by Fuerte Rav

I've debated with myself about using it for my Phals but I worry that I will damage the roots when I initially pot them in it and then anytime that I might have to repot - the pieces have such sharp edges! In your pics the pieces you use look much smoother/have rounder edges, or is that just the way it appears in the pics?

That's something I was concerned about when I gave pure scoria a shot a few weeks ago.

With forceps and some patience, I potted this small Phal bellina, and it didn't skip a beat. I keep the rocks slightly humid at all times, and the plant seems to really, really enjoy it!

Originally Posted by estación seca

I'm curious about the variegated Monstera - I've read they won't propagate by cuttings, but need to be tissue cultured. Are you rooting a cutting?

They actually do propagate very well via cuttings, and in spite of what people say on social media, can be regenerated from tissue culture.

The main issue is that success rate isn't high, yielding more green plants than variegated ones.

Somatic embryogenesis gives extremely good results, and I have some calli forming so I'll be able to experiment with that soon.

[SouthPark]

Also ------- one possible thing for ebay buyers to ask a seller is whether or not the stem node cutting has those outgrowth features (for the new leaves to develop).

From that same time-lapse video, it's noticed that the stem node cuttings that were eventually successfully propagated ------ all had those buds on them.

The remaining one didn't do anything or much at all ----- but still shows some hope of growing (because it didn't rot --- didn't change to black coloured over the duration of days). Not sure whether that last one actually made it. I wouldn't be surprised that the last one didn't actually make it - even though I think the person making the video mentioned something about a swelling or bump developing later.

Below is a screenshot (image) of the youtube video frame.

[SouthPark]

I think that - if I were to take a punt on inactive stem node cuttings ----- I'd look for those little outgrowths. But rooted stem node cuttings with growing activity will definitely be the best bet.

[Fuerte Rav]

Originally Posted by SouthPark

Oh geez ------ fuerte rav ----- if I lived next door to you, I'd never have to buy potting media ever again hahahaha.

Fantastic photo. I love the scenic look where you live. Wonderful.

I think scoria can have lots of forms - as volcanic rock is sort of general, but maybe the ones being sold for orchid growing have small little pockets all around ---- that can hold a little water for a while --- but not too much. But the combination of the scoria in the pot can allow the pot to stay humid and damp --- even a little wet --- for a while, and provide orchids enough water to grow nicely.

The scoria I use is locally called quincan gravel ---- pronounced kwing-kun gravel. But people call it scoria too. Some edges are a bit pointy, but never knife sharp. The type of scoria over here is no problem for grabbing with the hands - won't cut skin etc.

If it doesn't cut into skin - the type here ----- then it's ok for orchids. I can take some close-up shots today anyway ---- some good sample shots.

We have Molida (ground fairly small, we use it instead of sand for horticultural purposes as our local (shell) sand is too fine)
then Picón (pea sized pieces. The spawn of the devil, gets in your sandals, agony, sticks in soles of shoes and scrapes floor tiles, gets in pet's paws - won't have any in my garden!)
then Grava (2 - 3 cm pieces, my heap!)
then Grava grande (4 - 6cm pieces)
then Piedra negro : large pieces for building garden walls etc.

Grava:


Just dug out my last bill. I had 8 cubic metres delivered, 100€. And 40€ of that was the delivery, so about 7.50€ per cubic metre. (That was the 4th delivery in 4 years!)

I've got 2 phals needing repots once I see signs of new root growth so I'll give it a try. I'll start soaking and rinsing some Grava, not sure where on the island this particular batch came from, might be a bit salty.

Also very interested in the Monstera info. I didn't realise you could get variegated ones, never seen them, but love the look of them! I've got a basic green one that's got a bit leggy so I'll have a look tomorrow and see if I've got suitable bits for cuttings - a new project!

[SouthPark]

Fuerte rav ------ I think your kind is about the same as here. Ours often have extra dirt/soil stuck to it, which isn't fantastic - but it's ok. Your 2 cm size should work excellently.

The kind I use is exactly like in this pic link here: (photo link)
and will just upload it as well in case their link ever changes.

[Mr.Fakename]

Originally Posted by SouthPark

Also ------- one possible thing for ebay buyers to ask a seller is whether or not the stem node cutting has those outgrowth features (for the new leaves to develop).

Those outgrowths are the node! In more proper terms, they are "axillary buds".

That's the only spot where the new shoot will grow, without it a stem cutting is useless and will only grow roots.

As some rare variegated Aroids cuttings can retail for a small fortune, better be very careful. Scams are legions.

[Fuerte Rav]

Originally Posted by SouthPark

Oh geez ------ fuerte rav ----- if I lived next door to you, I'd never have to buy potting media ever again hahahaha.

Fantastic photo. I love the scenic look where you live. Wonderful.

My 'pot of gold' today!


Can't remember ever seeing so many rainbows as we have had this past few weeks. Just wish we had some rain along with them - all we're getting are a few odd spots that don't even join up on the floor.

[SouthPark]

Originally Posted by Mr.Fakename

Those outgrowths are the node! In more proper terms, they are "axillary buds".

That's the only spot where the new shoot will grow, without it a stem cutting is useless and will only grow roots.

As some rare variegated Aroids cuttings can retail for a small fortune, better be very careful. Scams are legions.

MFN ----- oh cool! Thanks for commenting about that!!

I previously assumed a monstera node as being the tan/brown woody portion between two green sections of the stem. And I think my assumption is actually correct - as in a 'node' is the intersection of two green sections ----- or rather, where a base of a leaf used to be, or where the leaf was once connected.

But - it appears that those extra features - actual nodules that look like outgrowths ------ are critically important.

This is good, as that will help buyers to really beware of ebay sellers that sell stem cuttings that don't have such outgrowths. Thanks MFN!

I personally would steer clear of sellers selling cuttings with no axillary buds (lateral buds).

Another nice link too (click here).

Originally Posted by Fuerte Rav

My 'pot of gold' today

Fantastic! And beautiful! I'd be digging for sure. That pot of gold is definitely just behind those trees. I saw it first.