Where does one find a "sandy loam"?

[Pushrestart]

Out of curiosity I walked over the major construction site and asked someone what the sandy colored piles were, turns out it was just beach sand and they get something like 80 tons a day?... I was hoping it was fill dirt and I could mix it up with everything else. Sandy loam you are an elusive thing, whenever I get out to CA I'll be sure to dig some up and bring it back.... for SCIENCE lol.

[greenknight]

Here in the Northwest, the soil in the flood plains is all sandy loam, too - volcanic mudflows have covered the valley floors with sand and gravel, which eventually becomes sandy loam. I don't use it in my cactus mix, but my sister-in-law once planted a Mammillaria elongata in a bowl of the stuff, and it did survive.

California soils have a similar origin, but most of their volcanoes are extinct.

[Pushrestart]

Here in the Northwest, the soil in the flood plains is all sandy loam, too - volcanic mudflows have covered the valley floors with sand and gravel, which eventually becomes sandy loam. I don't use it in my cactus mix, but my sister-in-law once planted a Mammillaria elongata in a bowl of the stuff, and it did survive.

California soils have a similar origin, but most of their volcanoes are extinct.

You are very lucky ! Ah its all that natural layering over time that makes things perfect.
My goal with attaining this soil was not to use it with cacti as it would likely be too dense. I really wanted this to be part of my mesemb mix and for seeds as its the ideal loam per lord of the mesembs.

[DaveW]

Virgin loam used to be the top spit (spade depth) of never ploughed meadow land. In short uncultivated soils. The turves were then stacked upside down until the grass had rotted. However untouched land is now rare in most developed countries therefore any old cultivated garden soil is now sold as loam, or worse still rotted composted materials of various sorts.

[jp29]

Deleted -- duplicate post

James

[jp29]

I have always experimented with soil mixes -- I think I have used about every one that has been devised during my growing lifetime (seventy five years) and in general I found all those that provided excellent drainage and root aeration produced healthy and robust plants for me -- regardless of the soil composition,

I have always strived to use very open, porous and gritty media in order to insure superior drainage and root aeration. No matter what the composition of the growing medium, it is important to keep the need for excellent drainage and good aeration constantly in mind.

I started off in 1939 growing my cacti in porous clay terra-cotta pots (with broken pot shards in the bottom for drainage) using the following ubiquitous (Vera Higgins?) "mix of the day":

1 part garden loam
1 part leaf mold
1 part sharp builder's sand

Here is an old photograph (circa. 1965) of an Arrojadoa rhodantha plant growing in Victorville, California (high desert approx. 90 miles north east of Los Angeles) using my mix of the day (basically Tegelberg's soil mix) which was:

1 part desert top soil
1 part desert plant leaf mold
1 part coarse desert wash gravel



That plant was as robust and healthy as any I am growing today.

And here is a photograph of one of my Arrojadoa rhodantha plants growing in Tucson taken about two years ago using a strictly mineral mix consisting of:

1 part coarse pumice
1 part sifted decomposed granite



And here is another Arrojadoa rhodantha plant growing at my house here in Tucson using my present soilless medium which consists of 30% coarse pumice and 70% Bach's Cactus Nursery mix:

6 parts screened coarse and uniform (3/8"/9.53mm) horticultural pumice
2 parts high quality Canadian sphagnum peat moss
2 parts well composted shredded pine tree forest bark



Of course, your own selection of a soil mix should be based on the specific requirements of the plants that you cultivate, your growing environment, your climate, how you house them and the type of containers you use.

James

[Pushrestart]

Virgin loam used to be the top spit (spade depth) of never ploughed meadow land. In short uncultivated soils. The turves were then stacked upside down until the grass had rotted. However untouched land is now rare in most developed countries therefore any old cultivated garden soil is now sold as loam, or worse still rotted composted materials of various sorts.

I agree with this, in most developed places, its near impossible to find 'untouched' ground by humans or chemicals of some sort, and unless I have the means to test and measure things I dont feel comfortable using it. Possibly more untouched places consist of deserts and uninhabitable places for people. But thanks for sharing the info!

@jp29 Thanks for sharing! I actually have your soil ratios saved, because this is what I'll be likely trying with my next round of mesembs and cacti seedlings. I never realized how difficult it is to find quality potting ingredients when growing in a non-native area. In dryer and warmer climates you can get away with a lot more