Napa 8822

[Joel143]

Am thinking of changing over to the NAPA. Would you just mix this with a good potting soil and be finished? Right now I use 2 parts sandy loam top soil, 1 part perlite and 1 part cactus soil mix potting soil. It drains fast and dries out in a few days but would like to change over. Any suggestions? Could I just add in the NAPA? Would I need to remove one of the other additives?

[iann]

Replace the perlite with NAPA. Drop the cactus soil completely unless you're growing leafy succulents. Probably you would also want more than 1 quarter of the mix to be granules. I use approximately 3 parts aggregate to 2 parts soil, which is for xeric cactis like Echinocactus and Copiapoas and for highly xeric succulents like Lithops. I actually use about 2 parts clay granules, 2 parts sandy loam, and 1 part alpine grit. The soil and granules alone is extremely light when it is dry so I add grit for a little extra weight.

If you want a mix that holds more water then consider replacing the sandy loam with a slightly heavier loam and still stick with the 3:2 ratio. Using less aggregate than loam just means that the loam fills up all the gaps between the granules and you might as well just have not bothered with them at all. Certainly if you used 1/4 - 1/3 grit in your loam then that would be completely pointless. The NAPA or perlite granules are at least porous so can retain a bit of air even when they are spaced out in the soil, but better if they are touching eachother and creating a proper lattice of air gaps.

One way to test whether your particular combination of soil and aggregate is correct is to try compressing it. Fill up a pot with your mix, shake a little to settle it, and then press another pot on top. The mix should hardly squash down at all. If it does then you don't have enough aggregate because the granules aren't touching eachother. Pure sandy loam squashes a bit depending on the exact content, but commercial cactus soil squashes a lot which is horrible.

[Joel143]

Thanks Iann for your reply. For to let you know I have a wide range of cactus types but majority are Trichocereus hybrids, San Pedro's, Echinopsis hybrids. Throw in some mamms and the like. I eventually want to do a raised bed for the Trichos and San Pedro's. Sorry so what it comes down to what your saying is just the NAPA and the sandy loam. Been trying to come up with a good mix but never could. Would you recommend me repotting? I've used the mix I've mentioned in majority of my cactus pots for a while now but now think with what your suggesting makes more sense to me. I've been growing cactus for a number of years but still feel like a newbie asking so simple of questions. Again thanks, your input is highly valued.

[Saxicola]

That is a neat tip about pressing down on the media to look for compression. It seems so obvious of a way to check the organic matter content but I never thought of it before! I've only gotten really serious about succulents in the last few months so I'm still playing around with various mixes to see what I like best. Your suggestion will help.

[Joel143]

Went to my locqal NAPA store who no longer carries it and won't order it for me. Jerk... Think it was an indepent store owner. Whatever. Anyway went to my local O'Reilly's who carries a 40 pound bag called Optisorb Oil Absorbant - Moltan - Oil Absorbent. $9.99 Ingredients are 100% Diatomaceous Earth with silica and sand. It says ganulation course....its about the size of a bb pellet...maybe slightly larger. Duh...I can't think today...its about the size of perlite to me. Will see what this holds when I wash it then make a mix of it.

[iann]

Moltan make three grades of their DE granules and Optisorb is the biggest. Look for Ultrasorb which is probably about right for most pots. There is also Selectsorb which I think is too fine. I'm not sure how hard and durable the granules are but I've seen Ultrasorb sold for use in soil.

[Steve Johnson]

Went to my locqal NAPA store who no longer carries it and won't order it for me. Jerk... Think it was an indepent store owner. Whatever. Anyway went to my local O'Reilly's who carries a 40 pound bag called Optisorb Oil Absorbant - Moltan - Oil Absorbent. $9.99 Ingredients are 100% Diatomaceous Earth with silica and sand. It says ganulation course....its about the size of a bb pellet...maybe slightly larger. Duh...I can't think today...its about the size of perlite to me. Will see what this holds when I wash it then make a mix of it.

Sounds promising. Just my $.02, but would you perhaps like to sift out the fines dry before you wash the O'Reilly's?. I had to do dry sifting with DG because trying to wet it first seemed that a lot of fines were clinging onto the coarser pieces I needed for my mineral mix. Some of the fines are still there (can't be avoided), but they wash out easily enough.

[Joel143]

They offer the Ultrasorb but was out of stock. Told me they've been out for over a month but was on order. So I seen the Optisorb, read the ingredients and figured it was pretty much the same. The Ultrasorb says medium granules and this Optisorb is course. Sorry couldn't compare the two but figured this should work just as well. Thanks Iann...never would of gotten all of this right without your input.


Steve - will see what it looks like when I start preparation on whether it needs sifting.

[Joel143]

Well mixed everything up and below are the pics once mixed. The final mix is what you see composed of 25 lbs of Optisorb and 40 lbs of sandy loam. Water goes right through. The consistency is pretty good I think...but again I'm new at mixing trying to find a good mix. I was using sandy loam, perlite and alittle cactus mix soil.

close up


regular shot

[iann]

Might even be a bit low on soil? My mix is darker than that at the consistency I like, but then my loam is almost black when it is damp. That does look like an authentic desert soil though, even if it's made from garden soil and oil absorber!

[Joel143]

Actually Iann you may be right. I was thinking it could use maybe another bag. I will mix another bag of soil in it. I might be using the same loam....it also is almost black...dry or damp. It can't hurt...the sandy loam is quick draining too due to the sand. Will post pics again after I mix the new batch.

[Joel143]

OK...added another two 25lbs bag of sandy loam. Its not totally wet. Just the moisture from the previous mixture. Im sure it will be closer to black when wet. So actually now the mixture consists of 100 lbs of sandy loam (maybe alittle more) and 50 lbs of oil absorber. Yea I like having extra potting soil at the rate I add to my cactus collection.

[tudedude]

I'm trying some napa right now. I like the stuff a lot. I'm doing napa/pumice/coir. Oh yeah, I ran into some coir at a local Bristol Farms, of all places. I think the coir is essential for water retention because the mineral mix can dry out fast.

[Joel143]

Since I've changed to this mixture it does dry out fast....but...with the rainfall in my area along with the high humidity I figured that this is good particularly since all my cactus though even in pots are all outside. I might have to water more often which I don't mind. I am planning a raised bed and will use the same mixture.

[Steve Johnson]

OK...added another two 25lbs bag of sandy loam. Its not totally wet. Just the moisture from the previous mixture. Im sure it will be closer to black when wet. So actually now the mixture consists of 100 lbs of sandy loam (maybe alittle more) and 50 lbs of oil absorber. Yea I like having extra potting soil at the rate I add to my cactus collection.

I've been trying to find a source for sandy loam in L.A., but all I come up with is the usual crappy commercial mixes. 25 lbs. should set me up for quite awhile, so is there a place I can find online for buying the loam you get? Yeah, sounds kinda silly to pay shipping for a sack of dirt, but if it's the right dirt I sure could use it.

Thanks!