Has anyone tried using a quarter or so volume
of pumice in half barrels? I have marine conditions with wet Springs and Winters with fairly warm dry Summers. I am looking for better aeration and lighter weight. I need to wheel my trees back behind my house for storms so must have a rigid container.
It would probably work, a better alternative IMHO would be DE. It’s cheaper probably too! Unless you have a source for pumice. I use 1 part in five DE. I use Napa Floor dry or even better Optisorb sold at O’Reilly’s auto parts. Napa floor dry is sold at Napa auto part stores. Both 100% DE, but make sure on the Napa as they sell another oil absorbent too. DE granules hold more water than pumice by weight. They might be a little heavier but still good. A mixture of 2 parts pine bark fines, 1 part peat moss, and 1 part pumice, DE or perlite (does not hold water, but drains it off), or the last part can be a mix of DE or pumice and perlite, that would be the best draining, yet retain water for the summer needs.
The pine and peat would be lightweight too, and everything should grow in it. This mix is nutrient poor, so you would have to add fertilizer. Tree-tone would work.
I think we are in the same area,sort of,Quill.I live in Redmond.
There is a nursery/farm supply store nearby and they prefer pumice over perlite because it stays more in place when mixed with other ingredients,whereas perlite tends to float upwards during irrigation.
I bought a 50# sack and like the results.It may be a little heavier than perlite,but at your ratio mentioned,there shouldn’t be too much added weight.
I still use perlite too. Brady
Well if you can get pumice like that I would go with the pumice, and agree Brady that perlite will float to the surface. I plan to eliminate using it and only use DE, but pumice is awesome too, I just think DE is better. I wish I could get the DE that Axis makes for horticultural use. Awesome stuff! Pumice holds about 40% of it’s weight in water, DE holds 120%. 1/4 inch nuggets of DE would be awesome! Axis makes it, but I have not found any distributors in this area.
Thanks Drew and Brady. I will give it a go then. Brady, I am close to you in Burien . Have you ever been to the K.I. S. Farm on Avondale? I got a compost tea aerator from them a few years ago. They have a huge variety of soil supplements.
That’s probably where I picked up the pumice.Nice place and only a few miles from my place. Brady
That’s great you have a source for it. Nothing around here I know about. So DE it is for me. I did order pumice once when I wanted to repot my cacti. Lava rock (yes pumice is lava rock too), what they call lava rock, the dark stuff works as well as pumice. I used pumice, DE, lave rock, and river rock for my cacti mix. Some pine fines too.They like an acidic soil and fertilizer.
I’ve used multiple cubic yards of pumice around here over the years, it works great in the soil/dirt, but in containers the surface pumice will float and go over the edge, that water level is easy to achieve in containers. Even with no overflow, the surface pumice will migrate to one part of the pot, but that is just a cosmetic event.
DE will not do that, but to tell the truth I have not seen that in pots with pumice. Maybe because I’m using larger pieces?
May depend on different sources of pumice. The stuff around here has a large grit and dust component that sinks in water. The larger 1/4"-minus pieces are the floaters. Whatever is sold as pumice can come out of the volcano with varying gas content and density.