I was sold on some Greensand from my local hardware store. I was told that it is high in nitrogen and good for alkaline soils which is exactly my current situation. My soil test revealed that my pH is 7.9, potassium is VERY HIGH and my Iron is nonexistent. I thought I found the miracle cure for my pH and Iron but then I read about the potassium in the Greensand.

Thoughts?

Jason

How high is very high? I'm approaching 400 PPM potassium, and not at all worried about it. I'm not stressing potassium sources, but some is still going down.

Nutrients have regions of consumption by plants--deficient, sufficient, luxury, and toxic. Some, like boron, have a very fine line between sufficient/luxury and toxic.

Potassium (and phosphorus) don't. The luxury consumption range is extremely wide on both. On nutrients where it's wide, always shoot for well into the luxury range to keep the plants happy. I'm working on raising my phosphorus in the gardens into the 60 PPM range, and wouldn't blink at 100. Potassium levels of 600 PPM are no issue at all.

Greensand is about 0-0-7, with the 7 being moderately available. I wouldn't worry about it unless you're dropping 50 pounds per thousand per year. Even then, I wouldn't worry about it much, but I would re-test with a place that reports PPM or pounds per acre to keep an eye on it.

My potassium when tested in May by UMass was 368ppm, pH was 7.9 and Iron was .4ppm. Does it sound like Greensand would be beneficial for me?

Yep. You're still under my K levels, and at that pH very few sources of iron will work for you. Greensand is a good option.

jcmdallas wrote:I was told that it is high in nitrogen...

Odd statement to make. I would take any of his/her advice with a big grain of salt (or sand).

jcmdallas wrote: I was told that it is high in nitrogen and good for alkaline soils which is exactly my current situation.

You need to find better sources of information as Greensand has ZERO nitrogen.

MorpheusPA wrote:Greensand is about 0-0-7, with the 7 being moderately available.

Maybe in your neighborhood, but not mine. More like 0-0-3. However I concur it varies from 0-0-3 up to as high as 0-0-7.

The mineral content depends on where it is mined and taken from. Personally I use it in th egarden and on a putting green soil less mix. There is one big negative with greensand, expense. Greensand is expensive and usually takes 40 to 60 pounds of it per 1000/ft2. Prices vary widely from 75 cents to $4 per pound. This is why most folks only use it in gardens rather than a lawn. However there is a flip side. One application usually last 3 to 5 years.

Yeah, I went to the highest number to cut it on the safe side--so the 50 per K is 3.5 pounds of (eventual) potassium release.

It could be a bit under half that. So much the better if that's the case, but I like to make sure the worst-case scenario doesn't send me screaming.

cactus wrote:

jcmdallas wrote:I was told that it is high in nitrogen...

Odd statement to make. I would take any of his/her advice with a big grain of salt (or sand).

I concur, that is a very odd statement to make. I'm not really sure what I meant to say but it wasn't that and the lady that helped me out did not say that. I swear I didn't open my beer until after noon.

texasweed wrote:There is one big negative with greensand, expense. Greensand is expensive and usually takes 40 to 60 pounds of it per 1000/ft2. Prices vary widely from 75 cents to $4 per pound. This is why most folks only use it in gardens rather than a lawn. However there is a flip side. One application usually last 3 to 5 years.

I paid $11 for a 40lb bag of Natures Guide Texas Greensand from Elliott's Hardware. texasweed may be familiar with Nature's Guide and Elliott's being from the North Dallas area.

I applied 10 pounds per 1000 but it sounds like I'll need more to have any impact on the soil.

At least I'll be able to sleep tonight knowing that I didn't screw anything up.

Jason

Did I say fifty? I meant five.

Kidding, of course. Ten per K is a good number, and I can't say I ever used much more than that (the expense thing again, plus my pH doesn't demand greensand). In my case, it's fortunate I don't need it as it's hard to find in PA.

I don't want to sound like I'm anti-organic, but a couple of years ago, I put down 20lb / k of greensand and didn't notice any benefit from it at all. It is very fine--the the point of being dusty. I wouldn't be surprised if 30% blew away in the wind at application. I personally wouldn't recommend greensand.

eriocaulon wrote: I don't want to sound like I'm anti-organic, but a couple of years ago,

What exactly were you expecting?

Rather than being high in nitrogen, you might have heard it was high in iron. That's usually what I hear. I'm not sure it is high in iron either, but it does seem to make iron available to the grass. The best use I've seen for it is when the acidity is washed out of the surface of alkaline soils by prolonged heavy rains.

It is expensive at 40 pounds per 1,000 square feet.

texasweed wrote:

eriocaulon wrote: I don't want to sound like I'm anti-organic, but a couple of years ago,

What exactly were you expecting?

I have iron issues, especially with my high pH, and also low K. I did not notice any change at all. Soil test still showed low iron and low k.

eriocaulon wrote: I have iron issues, especially with my high pH, and also low K. I did not notice any change at all. Soil test still showed low iron and low k.

Well ole TW is no chemist or soil biologist, just an ole dirt sod farmer, but if your soil has a high PH level then it cannot break down the greensand mineral and make Potassium and iron available to the grass. Greensand is basically a ground up rock, and needs a slightly acidic and moist soil conditions to break it down.

In your case I would look into using a product called Bonite, or start adding sulfur to your lawn.

I don't know how it works either but it seems to work to green up yellowed lawns after a heavy rain.

Here is my experience with greensand.

First, I have a heavy clay soil in a semi-arid area that is alkaline.

Second, it has performed miracles for me.

But, when it comes to nutrition, soil or other, every situation is fact specific. For instance, if a person has rickets from a vitamin C deficiency, a dose of C will have spectacular results. On the average person, not so much noticeable effect. And, now, with that in mind, here is my story.

In 2000 I moved in to a new 'old' house. It had pin oaks in the back yard. They were one at about 20 feet and two smaller ones, maybe 10 feet. They looked bad. Beleagured and covered in twigs. I tried everything, an organic sick tree recipe, regular fertilizer, more water. No improvement, steady decline. The smaller one died. Then, the second fall I had a bag of greensand left from applications to the lawn. Figuring the problem was likely some kind of problem with iron being bound up in the soil and not enough available for the pin oak's needs I dumped the whole 40 pound bag around the drip line. (What's $15 for a nice sized tree?)

The next year the tree literally revived from death's doorstep (I had even planted a replacement tree nearby). I've continued to give it one bag of greensand each fall since and it is a beautiful thriving tree ever since. Twiggy growth is a thing of the past.

Could have been the extra iron swamping the alkaline effect binding up the iron so the tree finally got enough iron, could have been the micronutrients greensand has and that tree needed.

All gardening is local. I say the same thing about myrachorzia, if you need it in your soil, adding some really makes a noticeable difference. If you don't, it won't help noticeably, if at all.

Greensand can help where the soil needs what it has, and won't for those with soils that don't need what it has. IMHO, try some and see if it helps. If it does, use it, if not, don't?!