HOW TO MAKE SOIL ACIDIC

[andyf]

How do I amend the soil to make more acidic for a palm Im in south fla so im in all sand?

[Mauna Kea Cloudforest]

Most organics will lower pH but the most acidic is peat moss, pine needles, bark and oak leaves. In addition to mixing in organics, use slow release iron sulfate pellets.

[MattyB]

I use a sulfur powder that's used to make Hydrangeas blue if I want acidic conditions. Not sure if it's available in large quantities.

[LJG]

Most organics will lower pH but the most acidic is peat moss, pine needles, bark and oak leaves. In addition to mixing in organics, use slow release iron sulfate pellets.

Have you tried the water soluble ferrous sulfate power? Thinking about running it through my fertigation system.

[JEFF IN MODESTO]

For me its a constant challenge.

My soil ph is around 7.5. And my irrigation water 8.2

I use fir bark as a mulch and sulfur power 2 times a year.

Jeff

[Phoenikakias]

For me its a constant challenge.

My soil ph is around 7.5. And my irrigation water 8.2

I use fir bark as a mulch and sulfur power 2 times a year.

Jeff

At which rate if I may ask? And what about if there is free lime (calcium carbonate) in soil? It is said that with free lime in soil, lowering ph is impossible http://www.ext.colostate.edu/mg/gardennotes/222.html

[Jerry@TreeZoo]

For me its a constant challenge.

My soil ph is around 7.5. And my irrigation water 8.2

I use fir bark as a mulch and sulfur power 2 times a year.

Jeff

At which rate if I may ask? And what about if there is free lime (calcium carbonate) in soil? It is said that with free lime in soil, lowering ph is impossible http://www.ext.colostate.edu/mg/gardennotes/222.html

For me its a constant challenge.

My soil ph is around 7.5. And my irrigation water 8.2

I use fir bark as a mulch and sulfur power 2 times a year.

Jeff

At which rate if I may ask? And what about if there is free lime (calcium carbonate) in soil? It is said that with free lime in soil, lowering ph is impossible http://www.ext.colostate.edu/mg/gardennotes/222.html

South Florida soils are not high in calcium carbonate, they ARE calcium carbonate. You can temporarily acidify your soil but not make it acid. Free sulfur works but sulfates do not (usually). It is hard to find it in 50lb bags but Lesco used to carry a sulfur coated iron chip product.

You can add a complete layer of organics on top of your soil using composted leaves or pine straw or tree mulch and renew it every year. Peat is acid but it also is a bit sterile and I think too much is harmful to healthy soil microbes and mycorrhizae. Remember that most of your feeder roots are within 8" of the surface so concentrate your efforts there. Plants will grow well with a good layer of topsoil and won't care what is deeper than a foot or so.

[JEFF IN MODESTO]

For me its a constant challenge.

My soil ph is around 7.5. And my irrigation water 8.2

I use fir bark as a mulch and sulfur power 2 times a year.

Jeff

At which rate if I may ask? And what about if there is free lime (calcium carbonate) in soil? It is said that with free lime in soil, lowering ph is impossible http://www.ext.colostate.edu/mg/gardennotes/222.html

Not sure about the application rate of sulfer nor whether there is free lime in the soil.

I can tell you that blueberries grow just fine where I've amended my soil.

Jeff

[Tyrone]

This is a big problem in Western Australia along the west coast within a few kilometres of the ocean as there is long limestone ridge that extends quite a few kms inland for most of the west coast. The soils if you can call them that are basically sand and crushed lime if it's not solid limestone cap rock. I've had to treat a few palm gardens in these areas. This is what I've learnt.

You must know the pH of the soil to begin with. If your soil is 8.4 or higher you have a real problem as what you have is basically crushed limestone for soil. Chemically speaking the soil pH will not drop until you have reacted all the limestone in your plot of soil with an acidifier. This is a very very slow process and incredibly expensive. The next option is before you plant your garden, remove the top 3 ft of soil and bring in good slightly acid humus rich topsoil. But who ever does that??

The big problem with limestone soils is that they lock up almost all the trace elements in your soil into carbonates which are not water soluble. Nutrient needs to be water soluble for a plant to take it up. One of the first nutrients to be locked will be iron. The symptoms of iron deficiency is yellowing in the new growth despite high levels of nitrogen in the soil. This is called lime induced chlorosis. The other things to be locked will be manganese, which causes shrivel top in queen palms, and many of the other trace elements. A deficient palm on limey soils will put out stunted or distorted growth which is not resistant to fungal or insect attack, and often the palm will decline into an ugly mess when really deficient.

How can you fix it? It requires constant attention. One way is to dig some 12 inch or more deep holes around the canopy of a palm and to fill these holes with acid rich compost that has been soaked in iron sulfate or some other sulfur containing solution. Iron sulfate is soluble in water whereas pure sulfur is not soluble. However it is cheaper to use pure sulfur than iron sulfate as an acidifier, it just takes a lot longer to react. Using a multi faceted approach to this will work the best. If you have plants which have become very seriously chlorotic and need help yesterday, then a treatment of iron chelates (very expensive) doused over the leaves and in the drip line will bring it back the quickest as the chelated part is almost immune to soil pH. If the soil needs a bit of a boost of iron the iron sulfate can be used more widespread in the garden. Finally sulfur can be applied as a side dressing every now and again with adequate irrigation and added humus and vegetable matter to work in the long term more effectively. In the end you may lower the pH enough and provide enough trace elements over time that the plants can get by and remain healthy with constant vigilance. But you'll likely never drop the pH from 8.4-6.4. pH is logarithmic so a soil with a pH of 6.4 is only one percent as basic as a soil of pH 8.4. Another way of looking at it is if you have to drop the pH from 8.4 down to 6.4, you have to remove or react with acid 99% of the limestone in the soil, and that's a huge if not impossible task in most cases.

That's what I know anyway.

[LJG]

Thanks Tyrone!

[Hammer]

Very informative Tyrone. Much appreciated.

[HorsesnPalms]

This is one of the best threads I have read in a while. I to have learned a lot. I have always wondered the same thing. Now I know how to make some of my palms happier. :-)

[trioderob]

tyrone-

I am printing out your thread and keeping it for ref

[Mandrew968]

Andy, aside from mulching heavily and maybe amending the soil just before planting a palm, I would say all else is a losing battle. Our soils are pretty basic but addding organics can enrich the soil--that does not mean the ph will change but the soil will be more fertile, which helps all the palms we can grow, look better.

[Alicehunter2000]

Sometimes it is nice to live up here in N. Florida with our slightly acidic sand. Then it gets cold....and I realize I have another problem to deal with. Great info on the top few inches of soil being the most important......I am going to mulch heavily with organics....horse, sheep and cow poo as well as pine straw.....as these are available to me for free.

[Tyrone]

Sometimes it is nice to live up here in N. Florida with our slightly acidic sand. Then it gets cold....and I realize I have another problem to deal with. Great info on the top few inches of soil being the most important......I am going to mulch heavily with organics....horse, sheep and cow poo as well as pine straw.....as these are available to me for free.

Yes, you can get one part of the equation right, then it's just the weather. But you gotta be positive.

I'm having to move to an area 250 miles south (southern hemisphere) where the average temps are lower, but I've been looking at buying a property that is basically peat. So nice amounts of organic matter at a pH of 6-6.5. It sure beats my dead sand up here.

[Alicehunter2000]

I've always wondered about Perth....would love to go there sometime....is the climate similar to California. I stayed a month over on the east coast around Brisbane and up north in the rainforest....but Perth interests me for some reason. Good surf....but sharky....yes?

[Jose Maria]

I enjoyed reading you Tyrone and agree with you.

Something related to soil pH, I have observed in Costa Rica. Acid soils, even rather acid(pH 5) and infertile soils, poor in all nutrients, is where most species of palm grow in the wild.

Limestone based soils have a smaller (spontaneous) palm population and then some palms adapted to these soils: Cryosophila grayumi, some Geonomas, and Chamaedoreas, and some others.

The problem with my evaluation is: maybe these palms growing now on acid and poor soils would like to grow on fertile soil too, but were wiped out by farming taking these soils in cultivation?And the bad soils were left alone..?

[Tyrone]

I enjoyed reading you Tyrone and agree with you.

Something related to soil pH, I have observed in Costa Rica. Acid soils, even rather acid(pH 5) and infertile soils, poor in all nutrients, is where most species of palm grow in the wild.

Limestone based soils have a smaller (spontaneous) palm population and then some palms adapted to these soils: Cryosophila grayumi, some Geonomas, and Chamaedoreas, and some others.

The problem with my evaluation is: maybe these palms growing now on acid and poor soils would like to grow on fertile soil too, but were wiped out by farming taking these soils in cultivation?And the bad soils were left alone..?

That could very well be true. Once widespread populations have been wiped out by farming and what is left is on those inaccessible areas where you can't farm or the soil is no good for farming.

From my experience Howea's actually like a bit of lime in the soil, especially if its sandy (hence they grow well along the coastal limestone regions of SW Australia) whereas Wodyetia really object to pH 8 and up. The Queen palm has a hard time on limestone and develops shrivel top problems too. Beccariophoenix sp windows hates lime soils and in my experience even neutral soils. It likes pH around 5.5.

[Tyrone]

I've always wondered about Perth....would love to go there sometime....is the climate similar to California. I stayed a month over on the east coast around Brisbane and up north in the rainforest....but Perth interests me for some reason. Good surf....but sharky....yes?

If you like blue skies, great beaches and surf, you'll like Perth and the west coast. Winters can be a bit miserable as when it does rain it can hang around. That being said there is still plenty of sunshine in winter. About 2 to 3 times the rainfall of San Diego. Summer temps are more like northern Mexico. The wind is always blowing on the west coast, either from the east or from the ocean. Yes, sharks are seeming to become more frequent, or maybe as the population is rising rapidly, more people are getting eaten. From a palm horticultural point of view, you get better value on the east coast of Australia, especially Queensland. If you like miles and miles of deserted coastline, you can head north from Perth. It's a harsh wilderness as you go further north. But if you like the wide open spaces, and driving miles and miles to get anywhere you'll probably like WA.

[LilikoiLee]

How do I amend the soil to make more acidic for a palm Im in south fla so im in all sand?

This post was reallly informative and will be very helpful to me. Thanks for asking the question Andy.

Lee

[JT in Japan]

Yes, sharks are seeming to become more frequent, or maybe as the population is rising rapidly, more people are getting eaten.

Great thread, worthy of a bump as I install my first irrigation system this weekend, and test the PH in my soil (4.5-5.5). *And* I get to learn about shark dietary habits! Ha!

JT

[sashaeffer]

I've used simple coffee grounds. If you need a lot, I guess some Starbucks will GIVE you their excess in 5 lb bags.

[Mauna Kea Cloudforest]

Most organics will lower pH but the most acidic is peat moss, pine needles, bark and oak leaves. In addition to mixing in organics, use slow release iron sulfate pellets.

Have you tried the water soluble ferrous sulfate power? Thinking about running it through my fertigation system.

Len, did you ever try the powder? I have used the powder here for temporary boosts. Works well to kick-start some palms and green up others.

[mnorell]

This is a great bump. Tyrone, you gave such valuable information in that one post. I have found myself in this limestone situation now for the past four years or so down here in the islands, and my own lessons learned are just to avoid any large-growing/foundation plants that are not highly tolerant of an elevated-pH environment. You can amend and amend and hope and hope, and the chlorosis and striping and frizzle-top are bound to return. Luckily there are so many wonderful palms and other plants that seem to thrive on this coral rock. But I do work to maintain some of my finicky heliconias and other things that I am wont to keep around me. And in an effort to create a nice hammock-like environment with a much richer substrate, I do keep every dead leaf, twig and any other vegetable matter here on the property...not a scrap is allowed to go to the trash-bins, unlike the majority of people down here, who have endless cans lining the streets, filled with coconut fronds and other trimmings. Talk about ruining the carbon cycle...

A very important thing to keep in mind is that municipal water supplies can be hellishly high in pH. When I was a kid in San Diego in the '60s and '70s, my sister and I would pour glasses of water from the faucet and watch the calcium flakes precipitate out of it. Our municipal water here in the Keys is advertised as 9.3, though I haven't personally tested it yet. I get chlorosis and other such nastiness on potted plants growing in almost pure peat, and I'm certain it's because of the pH of the water from the hose-pipe. If you irrigate at all without running it through an acid bath first, you are destined for ruin while trying to raise non-tolerant plants. Time for a rain-catchment system!

[Mauna Kea Cloudforest]

This is a great bump. Tyrone, you gave such valuable information in that one post. I have found myself in this limestone situation now for the past four years or so down here in the islands, and my own lessons learned are just to avoid any large-growing/foundation plants that are not highly tolerant of an elevated-pH environment. You can amend and amend and hope and hope, and the chlorosis and striping and frizzle-top are bound to return. Luckily there are so many wonderful palms and other plants that seem to thrive on this coral rock. But I do work to maintain some of my finicky heliconias and other things that I am wont to keep around me. And in an effort to create a nice hammock-like environment with a much richer substrate, I do keep every dead leaf, twig and any other vegetable matter here on the property...not a scrap is allowed to go to the trash-bins, unlike the majority of people down here, who have endless cans lining the streets, filled with coconut fronds and other trimmings. Talk about ruining the carbon cycle...

A very important thing to keep in mind is that municipal water supplies can be hellishly high in pH. When I was a kid in San Diego in the '60s and '70s, my sister and I would pour glasses of water from the faucet and watch the calcium flakes precipitate out of it. Our municipal water here in the Keys is advertised as 9.3, though I haven't personally tested it yet. I get chlorosis and other such nastiness on potted plants growing in almost pure peat, and I'm certain it's because of the pH of the water from the hose-pipe. If you irrigate at all without running it through an acid bath first, you are destined for ruin while trying to raise non-tolerant plants. Time for a rain-catchment system!

Why don't you invest in a rain catchment? Stored rainwater would be a much better source of water with much lower pH.

[Capnrey]

What methods are you guys all using to test soil PH??

Edited August 14, 2014 by Mantarey

[JT in Japan]

What methods are you guys all using to test soil PH??

I'm using this tool I insert in the soil. It has dual functionality. Not sure exactly how accurate it is, but this morning I tested my drinking water (tap water), and it gave me a reading of 7.0. Then I started adding pure lemon juice and the reading gradually changed to 5.5 then 5.0 before I got bored. Seems to work.

Jt

[Capnrey]

Interesting . . .$25 and two reviews on Amazon that are not in agreement. But looks worthy of trying out.