I have two questions:


1. Where can I buy coconut fiber, decomposed granite, and expanded shale? I want to make potting soil and I plan to make the blend recommended in the Library on this site, under the "Potting Soil" topic. It says the ratios/ingredients are:

30% Compost
30% Coconut Fiber
15% Decomposed granite
15% Expanded Shale
5% Alfalfa meal
4% Lava sand
1% Greensand
Beneficial microbes (bacteria and fungi)


2. Do I use this same blend for growing seedlings?
Or is there something special that seedlings need?

I wonder, specifically, (1) if the mixture for seedlings should have a higher ration of sand; and (2) if worm castings should be added.

Thanks in advance for reading & replying!!

You're in Arlington where there is a Redenta's located, and I'm sure they have many of those items. I find that a couple of the big stone and sand and dirt yards in my area (SW Fort Worth) have the granite and shale. I shop at Marshall Grain on Lancaster just east of downtown Fort Worth (I think they're also in Grapevine now) for my dog food (Muenster Natural) so while I'm there that's when I pick up dry molasses, corn gluten meal, lava sand, greensand, etc. In other words, you might find all of these at one place, or at a couple, but in the mid-cities area you have a LOT of choices.

I'd put the seeds or the established plants in this mix.

You need to read this thread.


Container Soils - Water Movement & Retention VIII


Over a thousand posts on container mixes.

For one season pine bark fines/perlite/turface or Calcined DE.

for long terms (read trees) turface or Calcined DE/perlite.

There's a ton more too it, too much to tell, just go read what you can.

The mix that LoveMyGarden posted in the first entry is the Dirt Doctor's recommended mix. This very long article you link to suggests some science behind the subject of pot drainage, something many people can use help with, but the contents aren't all so great. I don't recall ever hearing Howard recommend perlite for potting soil. I think you could achieve the same capillary action vs drainage with the items in the Dirt Doctor list.

That article should have an abstract at the beginning and a bulleted list for quick skimming. His idea about a wick in the pot might bear further study. Do you wick your pots?

Yes, I wondered about the perlite, too, as well as peat, which is mentioned in the thread.

I think I'll stick with the potting soil mix from the library (except I can't find coconut fiber )

Thanks to you both for responding to my original post!

Yes, it talked about moss and sphagnum, the contents of "peat moss."

The science in that article about wicking through or around the soil was interesting, but could probably be applied to the contents of the Dirt Doctor potting soil mix.

If you Google "Coconut fiber" you'll get lots of hits on lots of products but I'm sure there must be something local (I looked at Marshall Grain online and didn't find anything.) I use coconut mat to line hanging baskets on my porch, I suspect if you look around someplace like Home Depot or Walmart you'll find those and other coconut fiber items or bricks of mulch.

Hey LMG u can find compressed coconut-fiber at your local PetSmart or Petco. It will be in the reptile and amphibian section. It usually runs around 4-5 bucks for a brick of compressed-fiber. You may also pick up alfalfa meal at the pet store, although you will really pay for it. As for the other stuff on the list just grab your phone book and look under feed supply and give some stores a call to see what they have.

I found bags of pavestone decomposed granite at Home Depot this weekend. They're about 40-pound bags, the package says .5 cubic foot of decomposed granite. The bag cost about $4.59 and you can find it over near the paver stones and playground sand products.

Home Depot has a lot of coconut fibre things (pot liners, etc.) in there, most of it over in the indoor plant and planter section of the store. I didn't check out the range of coconut fibre products they carry.

All great stuff. Thanks everyone!