I am a new member of NARGS and I am so happy to know about this organization. I have always been interested in rock gardens, and now I am gonna be able to make my dream come true because me and my partner finally have our own house in Dallas TX! I will build a 12-cubic-yard berm with mossy sandstones on my south-facing front yard. The berm height will range from the grade level (where I will plant more water-needing plants) to about 24-30 inches at the very top of my "hill."
Now, I read hours and hours (well, let's say days and days) about desert alpines and the type of soil I should create, and I came to a conclusion that everybody has a different view on the best soil recipe!
Nonetheless, I found out there are essentially two recurrent recipes mentioned online.
Recipe option #1:
1 part of grit (I would use expanded shale)
1 part of sand ( I would use coarse concrete sand)
1 part of peat (I would use a mixed soil that is available at the same local quarry where I will also get the sand and the shale. It consists of a mix of topsoil, sand, and compost--this compost made of decomposing vegetation and manure)
Recipe option #2:
1 part of grit (expanded shale)
1 part of sand (coarse concrete sand)
2 parts of peat (again, mixed soil)
Mulch I intend to use:
1/2" limestone gravel
Since I am building a huge rock garden by creating a berm with 12 cubic yards of soil, I think it is imperative that I know what the perfect soil should be to grow my future plants! In my personal opinion, I believe that I should use recipe #2 because this recipe was mentioned in other websites by people who prevalently live in the South. For this reason, I believe a "too sandy and gritty" soil as in recipe #1 would be hard to maintain in North Texas, while it would probably be perfect for areas with more average rainfall.
Now, here with the plants I would like to grow:
Escobaria (Coryphantha) vivipara
Escobaria orcutti v. koenigii
Hirpicium armeriodes v.
Penstemon pinifolius 'Compactum'
Phemeranthus (Talinum) calycinum
Veronica spicata 'Glory'
Verbena peruviana 'Red'
Zauschneria california 'Wayne's Select'
Opuntia polyacantha ‘Taylor’s Red’
Opuntia aurea ‘Coombe’s Winter Glow’
Opuntia rhodantha hybrid ‘Grand Mesa Peach’
Echinocereus ‘White Sands’
Of course I am not going to buy them all, but I will select from this list.
What soil do you guys use and what do you suggest for my project?