Broken concrete in hole for citrus & fruit trees? N FL

Hi All,
I have low land that is acidic. The old time nursery people told me to put broken concrete blocks in bottom of the hole for citrus and fruit trees. And then of course the Ag Agent said that was a terrible idea. I have seen/tasted citrus from an island in the St Johns River that has a lot of old shell and it is consistently sweeter than other places. Anyone ever use concrete in hole or oyster shells as an amendment?
I'm in North Florida, any one else in this strange zone?

im assuming they told you to put concrete in the soil because it has lime in it. which will raise the PH away from acidic. same goes for oyster shells but i would have to say lime is more effective.

Tarzananda wrote:
Hi All,
I have low land that is acidic. The old time nursery people told me to put broken concrete blocks in bottom of the hole for citrus and fruit trees. And then of course the Ag Agent said that was a terrible idea. I have seen/tasted citrus from an island in the St Johns River that has a lot of old shell and it is consistently sweeter than other places. Anyone ever use concrete in hole or oyster shells as an amendment?
I'm in North Florida, any one else in this strange zone?

Yes, I'm in the strange zone - near Mill Cove of the St Johns River (Arlington/Jax).

Not sure about the concrete.

I have bits of  concrete on my soil wher there is some builders rubble and i always think it will stop the soil from being acid and avoid planting blueberries there and the dandelioins i have grow where there are a few bits of concrete from restoing the house lying around and paul wheaton says that dandelions like chalk soils. Bone would do the same, or shavings of  hoof and horn and such fertilisers. agri rose macaskie.
 

There are lots of ways to make concrete, but they almost all result in some free lime content. Older stuff will likely work faster; same goes for smaller chunks, of course. Modern methods may include some worrisome industrial wastes.

It might be worthwhile to pulverize a little of the concrete you have most available, with some of the soil you want to plant in, let them sit awhile with some moisture, and send the mix off for testing. That will both tell you how much you might need for the pH effect you want, and whether there might be heavy metals included. It isn't too unlikely that the concrete will contain other minerals that might be useful.

Hi All,
Thank you for your responses. It seems Concrete block pieces can support some needed lime over an extended time.
Besides or in lieu of pieces in the holes, I have 2' concrete scalloped edging that I was thinking of using as plant markers and for a very slow release of lime. Relative to the discussion, it seems this might be a good idea.
J. in my zone it's nice to know there is someone in my zone. I just ordered the Dave Jacke Book. Can you direct me to some good resources for our area. I'm 2 miles west of Hastings. 1000' from river with the benefit of 1.5 mile of river to west and 10+ miles to north. I'm berming for a food forest. Thanks

Not sure about resources in our area. The closest permaculture groups I have found are around Gainesville and Melbourne, and I haven't gone down to meet with anyone yet.  I was at the farmers market at Jax Beach, and came across a vendor who had a variety of perennial vegetables in pots for sale (chayote, Okinawa spinach, etc).... he was from somewhere down towards you, not sure if he is there regularly.  I read a variety of things online and off, and end up ordering most things online if the local nurseries don't carry it. 

  When i tried to get builders to tell me how to mix cement and finding it hard to get repllies and in the end bought books to look it up in.  I found that cement can be mixed with sand in lots of different proportions, more cement the harder the mix as far as i can make out and more water or wetting the cement  often more the harder the mix, so how much lime might be or might not be availiable to plants in cement maybe depends on which cement it is. rose.

  Talking of cement i did not know what it is made of so i looked it up and its made of clay and lime or chalk i don't know if it is lime or chalk. agri rose macaskie.

rose macaskie wrote:
  Talking of cement i did not know what it is made of so i looked it up and its made of clay and lime or chalk i don't know if it is lime or chalk. agri rose macaskie.

It's chalk as it goes into the kiln, and lime when it comes out. The process of turning back into chalk is part of the curing process, that hardens concrete.

You're absolutely right in the formula you give for traditional cement, but most of the concrete in America was made recently, and the cement in it was formulated out of a broad range of local minerals and industrial by-products like slag from iron smelters and coal ash. There is so much leeway in making cement, I'm tempted to compare it to feeding a chicken. An important thing is that any good mix will make for mostly-insoluble minerals plus some lime, such that even if some fraction of the recipe was contaminated with heavy metals, they are likely not bio-available.

That doesn't even go into the sand & gravel portions of concrete...even more variety is possible there.

I'm in Lake City.

Concrete can help with the acid by neutralizing with the lime, but I would avoid it.  The release will be slow, when all used up the aggregate will remain to serve as an obstacle to root growth, no way to tell what else is in the concrete. 

A more natural way to control pH is to promote the earthworm population.  What comes out the back of an earthworm is closer to neutral than what goes in.  Feed the soil plenty of compost, add worms if you need to.  Worms and their castings promote soil complexity.  It is that complexity that will enhance the flavor of the fruit.

Its a much slower method than adding lime, but its much healthier for the soil and the plants grown in it.

THoughts on concrete.     
I read somewhere that concrete is full of radioactivity full is an exageration contains would be a better word.
  There is a black mold that grows where there is radioactivity and i remember my father saying that concrete buildings, there where some good looking modern ones in the sixties such as the Hayward Gallery on the south Bank in London got ugly because they went black, maybe they go black becuase of this mold.
     CNN green program had a bit on a man who made paterns in dirty walls, did pictures in the dirt bleaching out shapes. I thought he is not being ecological what he sees as dirt is in fact different molds and lichens, maybe they aren't the prettiest combination of molds and lichens but if you let them build up they may get prettier.
  Maybe the clay in cement is full of uranium you can get uranium in slate soils and granite, i think is slate just compressed clay, i would say it was from its texture. I can of course look it up in google maybe will later.
  What other possibly nociviouse ingredients are their in concrete we should maybe be up in arms about. concrete is interesting.agri rose macaskie.

  Here traditionaly the walls are finished in lime, a mixture of sand and slaked lime one one that is pretty, it is much whiter  an dmore shiny than any sort of concrete finish that is full of clay.
    Wangari Mattai replastered her mothers walls as  a child in africa with ash and cowmuck she thought they looked as if they could do with a refubishing when she was on holiday from school, the ash must work like lime? Some mud buildings have an ash and mud bits, maybe finish, that would make a sort of concrete i suppose. agri rose macaskie.