Is Perlite Dangerous to Earthworms?

Hi all,

New here though I've been reading the forums for the last half year.

I have a question concerning the use of perlite in garden soil: if added, will it harm or irritate earthworms since perlite is popped glass and has some tiny sharp edges? I have not been using perlite extensively except in potting mixtures, where its water-holding capacity and soil loosening and aeration is very useful. However, in the ongoing crusade to improve my raised garden's soil, I've been considering it. My usual amendments include wood chips and bark mulch which has done much to improve the hard grey clay soil. I have a fast-growing earthworm population in the garden, since I transplanted them in and have been caring for them. But living here in the desert, I've been trying to get my garden to retain more water during the long hot and dry summers. Greenie part of me has concerns.

Not that this is conclusive but...I occasionally find worms in my potted plants (with perlite in the mix), alive and well.

I'd stay away from perlite use beyond potting mixes though. It's a mined aggregate...not so green IMO. You're on the right track with the bark mulch. Have you thought about bio char? there's info about it on this site.

Travis Philp wrote:
Not that this is conclusive but...I occasionally find worms in my potted plants (with perlite in the mix), alive and well.

I'd stay away from perlite use beyond potting mixes though. It's a mined aggregate...not so green IMO. You're on the right track with the bark mulch. Have you thought about bio char? there's info about it on this site.

Good to hear. Yes, I'm not really a fan of it, but I've noticed the plants in my perlite potting mixes usually thriving and even getting little mushrooms coming up happily (inoculated by the compost tea?) as I get super-sized plants.

I remember discussing this with one of my buddies who's a permie, and I think he was a great fan of it for garden soil use, but I know that it requires a lot of energy to produce perlite, and I agree with you, doesn't sound sustainable. Then again, a lot of garden supplies and materials are totally unsustainable/wasteful but sometimes we may make allowances. I have been putting in biochar with compost into the garden. Worms thrive in it, but it needs a little while to cure over the winter. It's still a little fresh, but has been inoculated with compost tea and other nutrient sources. I'll skip using the perlite in the garden.

With the downed maple tree branches I've had this winter from wild winds and heavy snow perhaps I can get some hugelkultur action going on. I've been piling up stuff all winter long and feeding the worms. I really need more of them to work this soil over good.

I've been using biochar for a couple years, but mostly indoors and with different mixes. I know where it hits its sweet spot. Miraculous stuff.

maikeru, where does it hit its sweet point ? rose.

I bet spores from the air are responsible for the mushrooms. Putting spores into the air is what mushrooms are for, after all.

Congrats on maintaining conditions for those spores to grow well, though!