Gritty mix for palms?

[Zeeth]

In looking for good potting soil amendments to improve soil drainage, I repeatedly kept coming across the same formula on Gardenweb and other sites for something called "Al's Gritty Mix". The base of the mix is a mixture of Turface, crushed granite (often sold as chicken grit or Cherrystone) and pine or fir bark in a 1:1:1 ratio, screened with insect screen or a metal kitchen strainer to a size between 1/8"-3/16". 1 tablespoon of gypsum is added per gallon of soil and the mix is supplemented with Epsom salt (for the Magnesium) and a complete fertilizer (I presume that you could add dolomite instead of the gypsum/Epsom Salt combo to palms like Coccothrinax and Pseudophoenix that like a higher pH). 

If Turface is difficult to find, certain types of oil drying material are suggested as replacements. Anything consisting of fired/calcined montmorillonite clay or fired/calcined diatomaceous earth supposedly work. Autozone sells this as their "Moltan Oil Absorbent" (part # 7133), and NAPA sells it as Oil Dry (part # 8822).

Pine or fir bark are easily found as "Reptibark" in pet shops, but are freely available elsewhere.

Crushed granite/chicken grit is supposedly found at feed stores, but many of the local ones use oyster shell instead of granite. They say that any material with a pH close to 7 in the 1/8" size range that has no internal porosity can be substituted. The people who use the mix say that properly screened pumice or gravel in the size range will suffice.

The mix seems to align with idea behind some mixes that I found the following posts on Palmtalk:

Any thoughts on the mix? I'm in the "internet research" phase, and I haven't grown anything in it yet. I'm afraid that the mix will go under-watered in my yard where most everything is watered with a sprinkler system while I'm gone, but I can hook micro-sprinklers to specific pots if I decide to try it on a small scale. It seems like an interesting mix for palms that require fast draining soil that are going to stay in pots for a very long time, so palms like Pseudophoenix ekmanii or Copernicia fallaensis might be good ones to grow in it. I may try a few Coccothrinax argentata first to see how they respond before trying more valuable things though.

 

[msporty]

I remember this mix too -- it was promoted for potted citrus but requires constant watering (daily here in dry SoCal?). I did buy turface once (it wasn't easy to find) and the guy at the building supply store thought I was a total nut when I told him it was for plants! Reptibark is expensive and seedling orchid bark will suffice at a fraction of the cost. Lastly, I have used chickgrit as a replacement for pumice when planting small, rare plants (mostly bulbs and succulents). It's nice because of its uniformity and lack of dust, but otherwise it's functionally pumice (I know it's granite vs igneous rock). I mix oyster shell in my cycad pots where I don't plan to repot annually (or ever)  as a buffering agent with some micronutrients, though I'm not sure if this really does anything other than make my potting mix more complicated.   

 

Give it it a go and let me know how you like it. I have grown Copernicia alba seedlings in 50/50 perlite/peat and I used my regular palm mix (peat, turf n tee, bark, sand, pumice, perlite) for Pseudophoenix sargentii without any detriment. I haven't done a head to head comparison, but I am planning to do so this Spring with Dypsis lutescens seedlings, but I digress...

 

 

[cm05]

Last year I switched my cacti/succulents over to gritty mix, it dries out quickly, you have to water it frequently. I couldn't see myself using it for palms with my poor watering habits, but everyone's different lol. I had to order the grit online, a 50 lb bag of Cherry Stone #2 for $5, which is wayyyy cheaper than you'll get at an agricultural store. I couldn't find turface either, so I used NAPA Oil Dry, and I found Reptibark on sale at Petco (online).

I'd also take a look into Al's 5:1:1 mix, I forget the exact make up, but it retains more moisture than the 1:1:1 gritty mix, I think it'd be more suitable for most palms. But for palms that require sharp drainage you can try gritty mix, and maybe a wick would help to keep your palms from drying out when you're unable to water them.