After watching the video in the link below of Martha Stewart visiting Chris DiPaulo of Belleclare Nursery, I must admit I came away scratching my head. I've never seen nor heard of top dressing a fig in a container with an inch or more of lime. He says it came about as an accident. You can't argue with success because their trees looked strong and healthy. It just seems like the thick lime topping would eventually harden like crème brulee. Some of you knew the DiPaulo brothers and spent a lot of time at their nursery. Perhaps someone can further expand on this practice. Does anyone else do this?

This is just speculation on my part, but I'm pretty sure his "lime" is ground limestone (CaCO3) which is entirely different than hydrated lime also called just "lime" (Ca(OH)2) which is different from dolomite lime CaMg(CO3)2.  

It does seem it would form a puck, unless it was a coarse grind.  Good Question.

Thank you for sharing this wonderful video.

It's just limestone but called lime. Just a figure of speech.

seven minutes from my house, I used to love going there.

It does not matter if it form a puck,it is helping the plant ,that is for sure.
Of course one can use granulated limestone and it will not form a puck.
Puck or not limestone helps,so they are right.
Of course as Dennis mentioned,they are talking about agricultural limestone and not about hydrated lime.

You don't need an inch on top. Limestone is nearly inert even mixed into soil unless finely ground. Setting on top it's basically inert. What you need is enough in the potting mix to achieve and maintain a pH above 7. That stuff on top doesn't help. It doesn't hurt unless it causes water to run off. Other than that it just sets there and does nothing. Waste of limestone IMO but the stuff is free here and probably cheap most places.

It does help:
The water penetrate trough the limestone when rain and takes with it some of the limestone deep in the soil mix,in the pot.
And in doing so it increases PH.
If you keep adding fertilizer,in that pot,the mix become more acidic every time you add.
Limestone will neutralize the fertilizer everyone is using when growing in pot!.
I wonder how some people can think that the old timers like the one described above did not know what they were doing.
Just look at their results and you will see,the true.
Happy Gardening

Herman:

Mixing the limestone into the soil is vastly more effective than placing it on top. Limestone is commonly spread on agricultural fields in the humid central and eastern USA where soils are acidic. It's always mixed into the soil. And the limestone must be very finely crushed. If not as fine as possible it can take decades to have any effect. Limestone is nearly insoluable in water. However nearly all well water contains some disolved limestone. That's because well water has been sitting underground for hundreds if not thousands of yrs and has become saturated with calcium carbonate ie limestone.

Watering with high pH well water will be much more effective at raising media pH than running water thru one inch of limestone on the surface. In fact I've used alkaline well water to raise the pH of potted blueberry media.

Just because a successful fig grower does something doesn't mean it helps. It may be that the practice just doesn't hurt anything. That's the case here.

I am not going to argue with you Steve because ,it seem you know it all,but ,look at the Video,The guy explain that he uses Granulated limestone ,especially so it will let water penetrate trough,and add a little limestone to the mix every time the pot is watered.
What you are doing is confusing new fig tree growers,so they could not become successful,at getting fruits ,at the first try.
My advice to new growers:Just do as ,those two old Italians are doing,and success will be yours,period.!
After all the above method is about growing fig tree in pot,specifically,and that is why granulated limestone is used.
Of course if it was about using limestone ,to neutralize soil in order to grow Corn,on a field,then very fine powdered limestone is to be used ,because it is fast acting,and of course it is mixed in the soil,in that case.
No offense Steve!

I have been meaning to put a post up on this I wondered if anyone else uses that much lime on there fig trees? My trees are in 5 to 15 gallon pots and each Spring I put a coffee cup full of lime on each of them 

Check out this post from Bill's Figs he uses 6 lbs of lime on his trees but he puts it in the bottom of the pot    http://figs4fun.com/bills_figs.html

Each year I put to large shovelful of lime on each of my in ground trees, they are happy.


 

This is my white fig tree, dont know the name

An inch of the stuff would serve to help keep the soil from drying out and keep it cool beneath as well help reflect the sun.

Interesting. I am exclusively growing in pots. 15 gal seems to be the largest pot I will use primarily because that's what I'm comfortable lifting. I'm currently growing over 225 varieties with another 25+ to be added this spring. I saw this video a few years ago and decided this method was not for me for a couple reasons.

I'm a landscaper. I understand the chemical benefits of lime and that's why I use it hydrated & granulated. I use about 1-2 cups per pot in the spring. The top dressing of lime (stone dust) may do the same job chemically, I'm not 100% sure. The problem for me is that limestone (stone dust) is heavy. Adding 5-10 lbs of it to my pot does not sound like fun when I have to move them twice per year. Also, when I need to trim the roots off every few years the stone dust would ruin the blade of my sawzall immediately.

Does the stone dust work? Seems like it does. If my trees were in the ground I think I'd try it. For me, it's not a good fit. I would not discourage any one else from doing it. Just understand that there are a couple downsides.

Herman:

You know, I hope, that I have high respect for your expertise and experience. That goes back to the old gardenweb. So there is no offense taken and never will be.

I hope I don't come across as a know it all. But 49 yrs as a professional soil scientist should entitle me to an opinion on this subject.

I'll give you one thing granular limestone on the surface won't hurt. But if new fig growers want to be successful add a hand full to the mix for each pot.

Just to remark on Dave's point about Bill's SIPs, the picture does appear to show Bill dumping hydrated lime into his pot, but as I am a Bill customer for several years I would point out: 1) Bill does not use or sell hydrated lime, he sells pelletized lime, which is what most of us use to regulate ph in our soil mix; 2) He nowhere specifically recommends dumping it into the bottom of the pot and in fact, in a SIP that might render the lime useless as it would dissolve close to the water reservoir at the bottom of the SIP, well below the root mass. I think if you ask Bill he will rather recommend either mixing it or top dressing. I admit the picture does not support this view but those are very old pictures, and Bill too has evolved. He does very succesfully grow huge and abundant fig trees in modified containers, which other than their weight are one of the most noteworthy collections of fig trees not in the ground.

I think adding the limestone either on top or bottom will work. Looks like it's done both ways. However, don't use the fast acting lime.....trust me.

Rafael is correct about Bill's SIPs too. My SIPs are built using Bill's method. The old photos of Bill making his SIP does show him adding lime. I called and talked with Bill about his setup from start to finish last spring. He said the photos are wrong. Meaning today, he does not use that white fast acting lime anymore. He said, today he only use pelletized lime.

When I make my SIPs, I do mix in some lime into the soil. My trees take off and grow very well.

Steve:There is nothing wrong with mixing limestone (fine) powder ,in the soil mix if the mix is acidic,in order to get the PH right.
However ,the one inch of granulated limestone in the top,is still needed,for the reason i described,and for the extra reason Jerry M described which is valid .
Also limestone powder is what i use on my in ground trees,and also,if i make my own mix.

ADelmanto:It is not necessary to apply that much in top,you can go as little as 1/2 inch.on surface,in order not to make your pot too heavy.
The procedure is good,yet the amount ,can vary so as to not make your containers too heavy to move.
When i grew in containers,i placed granulated (dolomite when i could find),limestone in top,sometimes ,half an inch sometime more sometimes less,depending,what quantity i had,but all i can say is that it works wonders.

Would you mind providing updated steps for Bill's method?

One of the fig growers here in Malaysia put seashells on top of the soil mix. His figs grows really well and he has no gnats problem too.

There's no need to write out steps. They're already there on John's figs4fun page. Just click, read and watch.

In the Bellclare video he mentions removing the suckers? Why? If you don't mind a bush instead of a tree, will these suckers eventually bear fruit?