Lava rocks for soil aeration and mulch; preferable to perlite?

[Jaz]

I saw a vid the other night and the guy was recommending lava rocks over perlite, particularly for those that re-use their soil.
His argument being that perlite will break down over time and turn into a silt whereas lava rocks don't break down.

I thought I'd read up on it and found a few tidbits pertaining to using it as a mulch:

they absorb heat well.
This might sound like an unusual advantage when it comes to gardening but if you lay down lava rocks as mulch, the heat they absorb during the day will keep your plants warmer at night.
This is especially good for potted plants that are brought in during the winter months.
Having the heat at night means they can last a little longer outside without needing to be brought in.

Pumice vs Lava Rock for Plants: Which is Better?

In summer, lava rocks act as mulch to reduce the premature evaporation of irrigation water. This keeps the garden soil moist and cool for longer, which your plants really appreciate.

How Using Lava Rock for Soil Additive Can Seriously Improve Plant Drainage

I'm keen to read thoughts and experiences with lava rocks - other than in hydroponics.

j

 

[Phytoplankton]

I’ve used lava rocks for growing epiphytic orchids, it holds some water and nutes, but for most orchids the orchid bark works a little better. Never used it for cannabis. It takes some pretty rough handling to turn perlite into dust. The vid guy is wrong, perlite doesn’t decompose, it’s basically volcanic glass (either natural or manufactured).

 

[Jaz]

The vid guy is wrong, perlite doesn’t decompose, it’s basically volcanic glass (either natural or manufactured).

I should've googled, it looks like you're right.

I still may try using lava rocks as a mulch.

j

 

[Jaz]

I spoke too soon, lol.

Perlite eventually deteriorates and gets "used up," which is why it's often combined with materials like compost, pine bark, peat moss, or other types of moss. The idea is to get faster and stronger root growth and then transition away by using less perlite later.

Perlite vs. Vermiculite: What's the Difference? (& How to Use Each)

I guess there are some opposing views out there, this one states it has a life span.

It’s inorganic nature means perlite absolutely will not rot and will not degrade or break down inside of a substrate for a very long time.
5+ years at least.
Trust me, you’ll need to refresh your substrate long before perlite becomes the problem.

What is Perlite? The Mineral That Rocks Your Plant Substrate

j

 

[Keffka]

I spoke too soon, lol.

Perlite eventually deteriorates and gets "used up," which is why it's often combined with materials like compost, pine bark, peat moss, or other types of moss. The idea is to get faster and stronger root growth and then transition away by using less perlite later.

Perlite vs. Vermiculite: What's the Difference? (& How to Use Each)

I guess there are some opposing views out there, this one states it has a life span.

It’s inorganic nature means perlite absolutely will not rot and will not degrade or break down inside of a substrate for a very long time.
5+ years at least.
Trust me, you’ll need to refresh your substrate long before perlite becomes the problem.

What is Perlite? The Mineral That Rocks Your Plant Substrate

j

I spoke too soon, lol.

Perlite eventually deteriorates and gets "used up," which is why it's often combined with materials like compost, pine bark, peat moss, or other types of moss. The idea is to get faster and stronger root growth and then transition away by using less perlite later.

Perlite vs. Vermiculite: What's the Difference? (& How to Use Each)

I guess there are some opposing views out there, this one states it has a life span.

It’s inorganic nature means perlite absolutely will not rot and will not degrade or break down inside of a substrate for a very long time.
5+ years at least.
Trust me, you’ll need to refresh your substrate long before perlite becomes the problem.

What is Perlite? The Mineral That Rocks Your Plant Substrate

j

Interesting.. I’ll have to do some more reading but if what I just read is true it sounds like perlite and vermiculite both have a place. Perlite would be good for veg when you’re trying for a wet dry cycle and vermiculite sounds like it would be perfect for flowering with its massive water retention capability.

As far as the actual topic goes, if 5+ years is the lifespan, it sounds like it’s a personal outlook thing almost. To me, lasting 5 years is more than enough to justify its use. However I know some people prefer to be able to use something over and over until their own death, so 5 years isn’t really worth it to them.