Where does one find a "sandy loam"?

[Pushrestart]

Hi everyone!

Have spent a significant amount of time reading up on various plant cultural requirements and feel like I've hit a wall. More with mesembs than cacti. I recently acquired a few mesembs, titanopsis primosii, agroderma pearsonii, and a few lithops. My understanding that this is the wrong time to buy and transplant them, but I plan to grow them indoors with additional lighting and warmer temps. My main obstacle has been finding a suitable organic component. I recognize the problems that come with bagged mix. I have gone to almost every nursery in my city and cannot find a suitable sandy loam. "Sandy what you say? ..." Everything sold is either peat or composted pine bark based. Locally the soil is very silt and clay based with almost no sand, the completely wrong stuff. Some landscape supply places will sell a pulverized topsoil (very dark) but dont think that's suitable. I understand I will have to cut any organic component by 70-90% with grit like granite chips, gravel, coarse soil etc. I recognize the delicate balance with the air to water ratio and that's the art of growing.
Sorry to start another 'soil' discussion, but can anyone offer suggestions or advice?

Thanks

[greenknight]

Loam is just topsoil that contains sand, silt, and clay in roughly equal proportions, sandy loam has a higher proportion of sand. You could add sand to your silty clay soil and make the equivalent, but you don't need the silt and clay - some people use soil in their mix, but you don't have to.

The thread pinned at the top of this forum covers the subject quite well.

[iann]

"Pulverized topsoil" is probably just composted organic waste. Calling it topsoil is a crime.

[Pushrestart]

Loam is just topsoil that contains sand, silt, and clay in roughly equal proportions, sandy loam has a higher proportion of sand. You could add sand to your silty clay soil and make the equivalent, but you don't need the silt and clay - some people use soil in their mix, but you don't have to.

The thread pinned at the top of this forum covers the subject quite well.

Thanks for the info, I'll check that thread out! I dont think that adding sand will suffice, the soil is this slick dark mess, even if I were to cut it with sand it would not be enough. I honestly question how anything lives in it, must be the abundant rain. Plus the sandy loam is a product which has been weathered and compacted over time and has uniformity which allows it to function as it does. Im just averse to potting soil presently because peat is a nightmare when dry, and not too familiar with how composted pine bark or eathworm castings play with these roots.

"Pulverized topsoil" is probably just composted organic waste. Calling it topsoil is a crime.

Ugh, really? I was initially tempted to try it, but with no additional info on its composition I decided against trying it.
Any other suggestions Iann, you are a master of mesembs!

[Aiko]

My understanding that this is the wrong time to buy and transplant them, but I plan to grow them indoors with additional lighting and warmer temps.

Depending on the species. Many mesembs are winter active. So Argyroderma and Titanopsis are fine to grow and repot now.

Sorry to start another 'soil' discussion, but can anyone offer suggestions or advice?

The loam I use (and am very happy with it) is loam you can buy at builders stores / shops, where they use loam to put on walls for insulation and such. There could be straw mixed in the loam for additional insulation, but you should also be able to buy it without straw, just 'pure' loam. Just look for a local building company that supplies loam for building purposes. There is no organic stuff in there, just the sandy loamy crumbling stuff that hardens like cement when dry and is soft as warm butter when wet. Ideal for sowing and ideal for mesembs (and even other succulents like Ariocarpus and other Northern Mexican species or other smaller cacti).

[Pushrestart]

Depending on the species. Many mesembs are winter active. So Argyroderma and Titanopsis are fine to grow and repot now.

Okay this is good news, so they should hopefully settle in without much issue.

The loam I use (and am very happy with it) is loam you can buy at builders stores / shops, where they use loam to put on walls for insulation and such. There could be straw mixed in the loam for additional insulation, but you should also be able to buy it without straw, just 'pure' loam. Just look for a local building company that supplies loam for building purposes. There is no organic stuff in there, just the sandy loamy crumbling stuff that hardens like cement when dry and is soft as warm butter when wet. Ideal for sowing and ideal for mesembs (and even other succulents like Ariocarpus and other Northern Mexican species or other smaller cacti).

Thank you for this, I looked online and again cannot find any near me, it is mad frustrating. All the sandy loams and similar soils are on the east and west coast (it makes sense), and Im right in the middle. After some digging online I believe the construction loam here is called "clean fill dirt", it has no organic matter. In pictures it looks different than sandy loam. I will keep looking maybe I can find it, sigh

[greenknight]

You don't really need it. I used to make my own potting mix from compost I made, which contained some soil (silty clay) and decomposed garden waste, along with peat and grit. Lately I've used a locally-produced potting mix containing earthworm castings, peat, and pumice, and add more pumice to make cactus mix. This works just as well.

Note that both mixes contain peat - a little peat is not a problem, you just don't want too much of it. Bark is ok, as long as there are no big chunks of it - you could sift it. Coir (aka coco peat - it's coconut husk fiber) is good but more expensive. You've got 2 choices - buy ingredients online and pay high shipping charges, or adapt to what you have available locally.

Builders use what's available locally, cheap. In the Netherlands they use loam because that's what's there. Around here they use fill dirt which is the local foothills clay, and builders sand which is volcanic sand (too much fine sand in it for potting mix) - I wouldn't use either one of those in potting mix.

[Ivan C]

I have been using mushroom compost as my "soil". I can't tell you if it will be good after prolonged use but so far it seems to fit the bill as best as I can get here. There does not appear to be any peat but it does have some larger chunks that I just sift out. To me it feels like "sandy loam".

[SoilSifter]

Soil at my location ranges from loam to sandy loam to sand but I rarely use it with my potted plants. The local soil, by itself in a a pot, will settle and become hard almost like sandstone. Also, it is alkaline. I make my own potting soil for cacti and succulents. I use a mix of potting soil that has some bits of bark, perlite, vermiculite, pumice, and grit. I wash the silt out of the grit. I've heard of people buying traction sand or chicken grit for their soil mix. Your plants might grow in sandy loam in their natural environment but I doubt that will work in a pot.

[Aiko]

Your plants might grow in sandy loam in their natural environment but I doubt that will work in a pot.

What should make the difference, you think?

[Pushrestart]

Soil at my location ranges from loam to sandy loam to sand but I rarely use it with my potted plants. The local soil, by itself in a a pot, will settle and become hard almost like sandstone. Also, it is alkaline. I make my own potting soil for cacti and succulents. I use a mix of potting soil that has some bits of bark, perlite, vermiculite, pumice, and grit. I wash the silt out of the grit. I've heard of people buying traction sand or chicken grit for their soil mix. Your plants might grow in sandy loam in their natural environment but I doubt that will work in a pot.

Very interesting! I have seen pictures online of growers who use a very sandy loam basically desert soil of sorts with their plants and it has a very compacted crusty appearance. It would probably work in the most arid environments, anywhere else is a bad idea. My understanding is that the plant and soil relationship in the ground is very different than that in a pot.
My goal with the sandy loam was to use it to cut the composted bark mix and make the organic component more gritty.
Do you mind sharing your mix ratios and how does one wash out the silt ?

[Pushrestart]

The loam I use (and am very happy with it) is loam you can buy at builders stores / shops, where they use loam to put on walls for insulation and such. .

This might sound crazy but a few streets down there is a MAJOR highway/construction project going on and there are HUGE piles of what looks like sandy loam and fill dirt and I am sooooo tempted to go ask someone there if it is, and if I can have/buy some.... FOR SCIENCE! I think I've lost my mind lol

[SoilSifter]

Your plants might grow in sandy loam in their natural environment but I doubt that will work in a pot.

What should make the difference, you think?

The same soil in a pot seems to work differently compared to the soil in a natural environment. I don't know what prevents the soil from settling in to an impenetrable blob in a natural environment. Probably multiple things are involved. The crusty stuff on top might cover loose soil below. I've noticed that happens with decomposed granite. Or, there might be a layer of cryptobiotic soil on top. At my location there are some small sand dunes. It might have a thin layer of crust on top but it is not easy to walk on because your feet sink in the sand. However, if put that same sand in a pot and water it for a bit then it will set like sandstone and the plant will have problems. The soil at my location has very little organic material.

[SoilSifter]

Soil at my location ranges from loam to sandy loam to sand but I rarely use it with my potted plants. The local soil, by itself in a a pot, will settle and become hard almost like sandstone. Also, it is alkaline. I make my own potting soil for cacti and succulents. I use a mix of potting soil that has some bits of bark, perlite, vermiculite, pumice, and grit. I wash the silt out of the grit. I've heard of people buying traction sand or chicken grit for their soil mix. Your plants might grow in sandy loam in their natural environment but I doubt that will work in a pot.

Very interesting! I have seen pictures online of growers who use a very sandy loam basically desert soil of sorts with their plants and it has a very compacted crusty appearance. It would probably work in the most arid environments, anywhere else is a bad idea. My understanding is that the plant and soil relationship in the ground is very different than that in a pot.
My goal with the sandy loam was to use it to cut the composted bark mix and make the organic component more gritty.
Do you mind sharing your mix ratios and how does one wash out the silt ?

I make it up as I go. Often I start with equal parts of everything. If it feels too gritty for the plant then I add some potting soil. If it isn't gritty enough then I add more perlite or pumice or traction sand. I have a few plants like Lithops that sip water so I put them in an extra gritty mix. I wash silt out of my sand or grit by putting a scoop of it in a large bucket then I get the hose and put some water in the bucket. Swish around the sand/grit and the water will become cloudy. Then I dump out the cloudy water. I do that a few times and the water becomes more clear. If you're more aggressive with the spray from the hose and stir up the silt more then the left over stuff feels more gritty. Maybe we should be posting pics of the sandy loam just to be sure we're talking about the same thing.

[SoilSifter]

The last time I opened a plant order from Mesa Garden there was some soil mix in the packaging. I noticed it is a sandy mix. I don't know if Mesa Garden uses pots for growing plants or something else.