Last month when I was down at the Arbor Gate nursery in Tomball, TX, the owner was promoting to me the benefits of expanded shale as a soil conditioner.

According to Doug Welsh of Texas AgriLife:

'Blue Shale' from the Midway Shale formation is present in a pattern across Texas through Corsicana to Texarkana and stopping near Laredo. It is usually found 10-15 feet underground. It was formed during Cretaceous times when Texas was a large lakebed and the lakebed sediments solidified under pressure into the present-day shale formation.

Jack Sinclair of TXI Industries has explained that the shale is mined and ground to 1" to l/2" range particles and then kiln fired. As it progresses through the kiln for 40 minutes at 2,000 degrees C, certain chemical processes take place in the silica content (60-70%) causing the material to expand. The expansion of Kitty Litter (calcined clay), for example, occurs at only 800-900 degrees.

As the material cools, cavities are left after gases escape, leaving a porous lightweight chunk capable of absorbing water and releasing it slowly at a later time.

I brought home a bag and have been messing around with it a bit but haven't used it long enough to really get a feel for its benefits. I will say, however, that the soil does have a better feel to it shortly after adding the shale. I plan to conduct much more trials during 2013. When planting new bulbs and perennials I've been mixing the material in with the native soil. I'm also wanting to add some to my potting soil, and I think it will be an excellent media for hydroponics/aquaponics projects.

If it does what I think it will, then I will likely get a dump truck load from TXI.

Has anyone else ever used this?

I started adding shale to my soil 3 years ago...I have both loamy soil & clay fill on my property. It does wonders to help loamy soil retain more moisture & helps clay allow roots to grow better & not compact so tightly. I add shale & compost with all new plantings to ammend the soil. It is the best thing I've found to allow my plants to flourish!
I keep a 40lb bag on hand & do add it to my potting soil!
I also like to use this soil for my containers that already has it in it...
Vortex™ Potting Soil from Lady Bug Natural Brand... High performance formula consisting of a blend of five beneficial compost, mineral sand, expanded shale and perlite.
Hope this helps,
Lila

That's very helpful, Lila, thank you for sharing!

TXI sells this by the truck where you can get something like 30 tons delivered. I'm just not sure I want that much but maybe I can split this up with some of my local gardening colleagues.

How finely divided is it when you get it? They said 1/2" to 1" before firing. Does it expnad even bigger, or crumble down to gravel or grit?

www.escsi.org
http://www.escsi.org/ContentPa...
"Originally patented in 1918 as Haydite, Expanded Shale, Clay and Slate Lightweight Soil Conditioner"

I'd like to add some eternal, porous coarse grit with water retention to my beds! It would be even better as coarse fibers or twisted ribbons 1/2" to 2" long, 3-4 mm wide and 1-2 mm thick


I keep thinking about putting some bark strips or nuggets into my microwave to see if they expand or pop, and hold more water while still creating big air spaces.

I've seen the TXI stuff and it gets pretty small. The pieces are about the same size or slightly smaller than pea gravel.

>> slightly smaller than pea gravel.

Thanks. I bet that would be great in containers & planters.

Definitely.

They produce a similar product here they market as Utelite...I have not tried it but may

Enjoyed those links and now I know what black gumbo is. I wonder if this would work similarly to moisture crystals for bog/water loving plants in ground.

Here are pictures of the shale I buy locally from several sources including a local feed store & it ranges from $7-10/ 40 lb bag. The advantage of shale is that it doesn't compress or break down in you soil so it continues to provide aeration for roots to my heavy clay soil as well as helps with sandy loamy soils to retain moisture!



Good luck,
Lila

That's exactly what the product I'm looking at looks like. In fact, probably they are all coming from the same place outside Dallas.

My cost is about $50 per cubic yard, delivered to my ranch.

We added a couple of bags to our veggie garden this year to help with drainage since we have that lovely clay soil. We've gardened in this plot for about 4 years and every year we've added compost. We've also added green sand. Both help with drainage and this year our garden was the best yet!

I just found this thread. I would sure like to give this a try. I have tried to do a search to see if I can buy it in Oregon, but can't seem to find anything.

I'd like to try some in pots, mixed into the potting mix. I've never seen it sold locally as "expanded shale", or didn't recognize it as such. But I have seen this brand name stuff, which seems to be the same. Next time I'm at the store, I'll get some.

http://wormsway.com/detail.asp...

Karen

Thank you so much Karen, I found that brand locally in Salem.

Cool!

I've never tried hydroponics. But that store (Worm's Way) has a store not too far from my house. I love to go there. They just have the most interesting stuff! From grow lights to potting soils...every kind of growing media... propagation stuff...containers...organic ferts...composting stuff... I go there to pick up one single item, and end up spending a couple of hours. And the staff is so nice.

Really, even if you have no interest in growing hydroponically, any gardener could find a hydroponic store an interesting place.

Karen

We have one in Salem/Keizer that I have been to a couple of times. I agree with you, very fascinating stuff in there. Needless to say I will be visiting them again in the near future.

I got a small bag of the Sunleaves Rocks 0.25 to 0.5" size, (expanded shale) to try mixed with potting mix in a few containers. Any suggestions how to mix it? I'm thinking about a third shale by volume? Any comments?

Karen

That link I gave in the first post of this thread suggested a 50/50 mix. I think anywhere from 1/3 to 1/2 would be good.

Thanks Dave, I'll give it a try. (It has been too long since I first read the link. I had forgoten already. )

Karen