I have a read a few posts (a couple from Herman) that mention adding limestone to both in-ground and potted figs. I have granular limestone (brown) and powdered dolomite (white) and agricultural limestone (white). So what is the practice? How is it applied?

Hi JD.  Hope you are well my friend.

First, I don't have an answer unfortunately, but I appreciate the question.  I have been wondering the same thing.

Figs have been grown for thousands of years, and given that, it's amazing how little has been written about growing figs.

It's easy to learn that blueberries like an acid soil; beets like a lot of lime, but what is best for figs?

I hope someone can help with this, as if lime is good for the figs, that is an easy thing to do.

As far as I know too, lime is just lime, although in different forms it may be absorbed quicker when ground finer, etc.

But unfortunately I have more questions than answers about this subject, and look forward to hearing from others.

Best wishes.

John

I use pulverized limestone.

From Clemson:

I. Liming materials

To be considered a liming material an anion must produce OH ^- ions to react with H⁺ and Al³⁺ ions. Oxides, hydroxides, carbonates, and silicates

1. Calcium oxide (CaO)

Common names - burned lime, quicklime, unslaked lime

CaCO₃ ===> CaO + CO₂

Advantage is immediate reaction with the soil.

Disadvantage - caustic, difficult to handle and apply

Caking may occur. Through mixing is necessary

 

2. Calcium hydroxide (Ca(OH)₂)

common names -- slaked, hydrated, builders lime

CaO + H₂0 ===> Ca(OH)₂

Advantage - quick reaction with the soil

Disadvantage - difficult and unpleasant to handle

3. Calcitic limestone (CaCO₃)

Dolomitic limestone (CaMg(CO₃)₂)

Mined from deposits. Quality depends on amount of impurities such as clay. Good handling properties. Reaction time several months.

4. Marl (CaCO₃)

Unconsolidated deposits of CaCO₃. Usually contaminated with clay. Low in Mg.

5. Slags (CaSiO₃)

byproduct of furnaces used for making iron, steel and elemental P.

6. Fly ash

J. Placement of lime

Through mixing of lime throughout zone of root growth is ideal.

1. Particles of lime do not move in the soil.

2. Application - Spread half of lime and plow down. Spread other half and disk.

On established sods lime must be topdressed. Reaction is slower and less complete. * Add smaller amounts more often.

Is there a PH to achieve?  I live in an acid area underlain with limestone.  So from one part of the yard to another can be quite different in some instances.  However, for azaleas, we need to add some acid.  But unfortunately can't grow Rhodos, Mt. Laurels, and deciduous azaleas - too hot, especially at night.

7-8 closer to 8

I think figs do better with a pH between 6.5 and 7.  Last year, I used the a little bit of the powder limestone any it stressed my trees out.  They recovered about 4 weeks later.  From now on, I will only use the pelletized lime and so far has not stressed out my trees this year.  I learned my lesson!

Yeah that's the problem what works for one doesn't work for another. I have heard it should at least be neutral if not more alkaline. The recipe i use is to add lime every year but at the edges so that the tree can tap into it and it can slowly leach into the soil for balance.