Lava Rock, Minerals, and all that Jazz

[_Keith]

I have seen the phenomenal growth of palms in Hawaii. I am sure it is temp ranges, rains, and such that make a tremendous difference. But the one thing I could actually do here, and truly wonder about how much difference that mineral rich lava rock makes. I tend to think it is a major contributor. The stuff is hard to find here nowadays, but I could get some minor amounts here and there. So here is the thing I wonder about.

While I could mulch with it and let the rains wear it down and work some minerals down into the soil, I could also pulverize it, add the powder to the soil, but what about just putting a good size chunk, maybe half gallon to one gallon size right down in the planting hole right under the palm. The roots would be free to attach to it, as would the abundance surface area be free for soil life to colonize to further provide mineral to the plant availability. It seems to me, this might be the ideal way to use it.

Any thoughts?

[Xerarch]

I have wondered if the palms in Hawaii aren't doing well in spite of the rocky soil, not because of it. Sand has very little capacity to hold on to nutrients, and I have a hard time seeing how lava rock would, in general, the smaller the soil particle, the more nutrients it can contain, the larger the particle, the better the drainage. That's why a sandy loam is often considered the best mix to have, sandy for good drainage yet has some silt and clay to hold on to water and nutrients. Anyway, other than fast drainage I don't see the advantage to lava rock from a soil science perspective even though I have heard others praise it on this forum. Perhaps someone can enlighten me.

[_Keith]

Albeit, this is not the use I was thinking of, pulverized, here is a big debunk for sure.

http://www.oakwilt.com/field_report5.html

Perhaps it is just the surface area it provides for the colonization of beneficial soil life. Or perhaps it is just wishful thinking all within my mind. We all want every edge we can get.

[Xerarch]

Actually I didn't mean to imply lava sand although I see that I sort of jumped right to it and didn't really explain my thought process, my point about sand was just the differences between large and small particle size, with rocks being much larger than sand, you can't expect them to hold more nutrients than sand, which has poor nutrient capacity. As far as surface area that you mentioned, that is really at the heart of the ability to hold water and nutrients. The smaller the particle the more surface area there is per given volume that can interact with water or nutrients at the molecular level, this especially true with clay whose particles are actually not round like sand or silt, clay particles are like thin plates, they stick together like two sheets of glass with a bit of water between them. That's why clay adheres to itself so much, and that's why it holds so much water and nutrients. Unfortunately it holds them so well it's hard to get them out sometimes, that's one reason a highly clay soil isn't any good either.

[Walter John]

I have seen the phenomenal growth of palms in Hawaii. I am sure it is temp ranges, rains, and such that make a tremendous difference. But the one thing I could actually do here, and truly wonder about how much difference that mineral rich lava rock makes. I tend to think it is a major contributor. The stuff is hard to find here nowadays, but I could get some minor amounts here and there. So here is the thing I wonder about.

While I could mulch with it and let the rains wear it down and work some minerals down into the soil, I could also pulverize it, add the powder to the soil, but what about just putting a good size chunk, maybe half gallon to one gallon size right down in the planting hole right under the palm. The roots would be free to attach to it, as would the abundance surface area be free for soil life to colonize to further provide mineral to the plant availability. It seems to me, this might be the ideal way to use it.

Any thoughts?

I agree with the many thoughts here with the pivotal advantage being good drainage, not so much mineralising the soil.

[Dypsisdean]

Please allow me to confuse the issue while offering no real answers.

After gardening for a while in Hawaii, the one thing you notice about lava is that there are many types. There is a'a (pourous, jagged), pahoehoe (more solid, almost like a parking lot at times), blue rock (a granite), cinder (what you see in pots from Hawaii), and all gradients in between. Add to that the age (very important), and color (black, red, or brown/older), and you have quite a selection to choose from - all with different properties. And that is just on one island.

I have used lava rock a lot in SoCal for landscaping, and can attest that the lava there is different still than what we have here, with it's own characteristics, like the light grey feather rock.

So I guess the purpose of this reply is to point out that the term "lava" can or could be very misleading, and more specificity may be in order to discuss accurately.

[_Keith]

Please allow me to confuse the issue while offering no real answers.

After gardening for a while in Hawaii, the one thing you notice about lava is that there are many types. There is a'a (pourous, jagged), pahoehoe (more solid, almost like a parking lot at times), blue rock (a granite), cinder (what you see in pots from Hawaii), and all gradients in between. Add to that the age (very important), and color (black, red, or brown/older), and you have quite a selection to choose from - all with different properties. And that is just on one island.

I have used lava rock a lot in SoCal for landscaping, and can attest that the lava there is different still than what we have here, with it's own characteristics, like the light grey feather rock.

So I guess the purpose of this reply is to point out that the term "lava" can or could be very misleading, and more specificity may be in order to discuss accurately.

Excellent point, I know squat about the different kinds, so thanks for your post. The porous jagged stuff, reddish in tint is the only thing sold here, so pretty much that would be what I would be able to use.

[Alicehunter2000]

Seems to be working pretty well in conjunction with beach sand for D. decipiens. Things are looking good so far. Maybe the red lava has enough pores in it to hold water fairly well?

[Kim]

I can say that if palms in Hawaii are not fertilized, they won't necessarily look their best. You can see photos of older Hawaiian gardens where no fertilizer regimen is in place, and the palms are yellow. I do not personally subscribe to the idea that palms get what they need from lava rock, beyond perfect drainage. The "cindersoil" I buy for planting in Hawaii contains some clay material mixed with the cinder which I thinks provides some nutrients, but spending $$ on fert in lava is important for the long haul. Just my two cents.

[_Keith]

I can say that if palms in Hawaii are not fertilized, they won't necessarily look their best. You can see photos of older Hawaiian gardens where no fertilizer regimen is in place, and the palms are yellow. I do not personally subscribe to the idea that palms get what they need from lava rock, beyond perfect drainage. The "cindersoil" I buy for planting in Hawaii contains some clay material mixed with the cinder which I thinks provides some nutrients, but spending $$ on fert in lava is important for the long haul. Just my two cents.

Well, you would be one to know. Thx for the feedback.

[Mauna Kea Cloudforest]

Having combed the Big Island for palm growing real estate, the common thread from all growers was "a place on the island with soil is much, much better". Jeff Marcus likes to point out the insanely different rates of growth for the same species planted in different places in the garden. That's because when you plop the palm in the ground, you can't see what's beneath, you could be planting the palm in a good section where there is lots of porous lava, or you can plant it on top of a lava hollow, or even a solid lava chunk. Theres' no telling.

I use ample red lava rock in my garden, and given how mineral hungry palms are, there has to be some benefit from mineralization that comes from the lava rock, but in the end it's just a nice complement for both ornamental reasons and available minerals but it can't sustain the palms on its own. It's great for better aeration of the soil, it accumulates more heat, and it looks nice. I use it on pots as a mulch to keep watering requirements low. For that, it works very well. I also use it as mulch along the base of dypsis to keep rot at bay.

[Jerry@TreeZoo]

I Would think that adding lava sand to clay would result in the same outcome as adding any other type of sand to clay...concrete. To amend clay, you should use organics. I agree that there are several types of lava and probably more types of lava sand, each with their own properties. Adding lava sand to Florida soils can improve things greatly if you use the right stuff. I have used zeolite to great affect. Sandy soils drain quickly, usually have low cation exchange capacity but great aeration. If you add zeolite or some similar lava sand it increases the cation exchange capacity. But that is not the whole story. You need to fert to get the nutrient content that the lava sand will hold on to in the first place. If you use organics, this lasts longer and as it breaks down, nutrients are held by these cation exchange sites. The problem with organics is that they break down and must be replenished. Lava sand is permanent.

Adding organics to sand or clay is good but to extend the benefit of organics in sandy soil you can use some lava sands (zeolite works for me) to great affect.

[edric]

Potting mix for Dypsis in FL. Ed

[Funkthulhu]

Not to dilute the conversation even further, but is this about drainage or mineral availability for the palm in the soil it has? I purchased a bag of "Azomite" this spring, I've been applying it to any repot, and sprinkled it over some of my garden plants. My results are good, but once you factor in weather and the use of compost, I'm not sure if their is a statistical gain in growth or health of my plants. (I should have run a control with no Azomite, and another with Azomite but no compost)

Anyway, anybody else ever used a rock-dust supplement product on their palms? Did it help?

[Mauna Kea Cloudforest]

I use azomite on some of my palms, and I honestly don't see a difference. I tried adding it to some not so healthy palms, since it supposedly improves the health of plants, but the results were not impressive. Might have better luck with crystals sending out good vibrations to the plants, or play Mozart for my palms.

[Silas_Sancona]

Erik (Funkthulhu)

Have used rock/mineral dust (Excelerite / Granite dust) a few times with good results, though nothing stellar. Have also heard of rock dust being used by commercial fruit growers to replenish minerals in over worked/eroded soils. Supposedly resulting in higher/ better yield. As far as the benefits of Lava rock go, I use it mainly for aeration alongside stuff like Pumice, Calcined Clay, or grow stones in my soil mixes. If there is any mineral benefit, id think it comes as the stone decomposes. Id assume that any stone would hold some mineral release potential as it is broken down/ weathered.

-Nathan-

[edric]

I use this mix to keep Oxygen in the soil, I also use Diatomaceous earth, also known as D.E., diatomite, the white powder you use in swimming pool filters, and Greenganic, for a fertilizer, Ed

[LJG]

I use this mix to keep Oxygen in the soil, I also use Diatomaceous earth, also known as D.E., diatomite, the white powder you use in swimming pool filters, and Greenganic, for a fertilizer, Ed

Ed, where did you hear about Greenganic? Not many have heard of it yet alone used it. I love the stuff and truly believe it is the real deal. So many organic ferts or amendments are based on anecdotal accounts. I can say this is not the case with Greenganic. This has just as good backing here as it does in places like New Zealand and South Africa (Nitrosol there). I am slowly replacing all my EZFlo's with Dosatrons just so I can fertigate with it.

[edric]

I use this mix to keep Oxygen in the soil, I also use Diatomaceous earth, also known as D.E., diatomite, the white powder you use in swimming pool filters, and Greenganic, for a fertilizer, Ed

Ed, where did you hear about Greenganic? Not many have heard of it yet alone used it. I love the stuff and truly believe it is the real deal. So many organic ferts or amendments are based on anecdotal accounts. I can say this is not the case with Greenganic. This has just as good backing here as it does in places like New Zealand and South Africa (Nitrosol there). I am slowly replacing all my EZFlo's with Dosatrons just so I can fertigate with it.

Hi Len I heard about Nitrosol & Greenganic from you, in an old thread where you were raving about it, so I checked it out, but as you know you can't get Nitrosol here in the states, Greenganic is supposed to be the same thing, what say yee, Ed

[LJG]

I use this mix to keep Oxygen in the soil, I also use Diatomaceous earth, also known as D.E., diatomite, the white powder you use in swimming pool filters, and Greenganic, for a fertilizer, Ed

Ed, where did you hear about Greenganic? Not many have heard of it yet alone used it. I love the stuff and truly believe it is the real deal. So many organic ferts or amendments are based on anecdotal accounts. I can say this is not the case with Greenganic. This has just as good backing here as it does in places like New Zealand and South Africa (Nitrosol there). I am slowly replacing all my EZFlo's with Dosatrons just so I can fertigate with it.

Hi Len I heard about Nitrosol & Greenganic from you, in an old thread where you were raving about it, so I checked it out, but as you know you can't get Nitrosol here in the states, Greenganic is supposed to be the same thing, what say yee, Ed

Ah, Ok. You have good memory as I don't even remember mentioning it before.

Yes, it is the same thing for sure. The stuff is liquid gold as you are finding out. Great organic option!

[Mauna Kea Cloudforest]

Len, does greenganic have a palm fertilizer version or do you have to supplement with trace and extra K and Mg?

[LJG]

No, just what you see. I supplement all my Tropicals when I use organics.

[MKIVRYAN]

I have been mixing crushed cinder into my clay soil for about 2 years or so now. I'm not sure if it's making any difference but I thought it can't hurt. I have noticed much better drainage and some of the palms seem healthier but that could be due to the drainage as well. Is there a link to this greenganic?

[Moose]

http://www.greenganic.com/

[LilikoiLee]

Move here. We can always use more palm nuts!

Lee

PS: I'll sending you a PM in the next few days.