Clay Soil Amendments

[Dartolution]

Hi everyone, 

I just wanted to know how many of us here have had to deal with dense clay soil.

How do you treat it when planting palms, and what amendments have you used to help break it up?

This spring I plan on planting a mule palm, sabal blackburniana and a queen palm and will need to amend the soil around them heavily. 

 

Any advice is great! 

Please share your experiences as well. 

[Ben in Norcal]

1 minute ago, Dartolution said:

Hi everyone, 

I just wanted to know how many of us here have had to deal with dense clay soil.

How do you treat it when planting palms, and what amendments have you used to help break it up?

This spring I plan on planting a mule palm, sabal blackburniana and a queen palm and will need to amend the soil around them heavily. 

 

Any advice is great! 

Please share your experiences as well. 

I plant all of these species in dense clay soil and they do wonderfully.  Clay is some of the highest nutrient soil you can get, and all of these plants don't mind high water content.

I top dress but don't really believe in amending soil for species such as these...they'll all grow in basically anything.  And, clay is some of the best soil you can get for these plants.

[Chris Chance]

I believe your palms will do great if you just add some amendment mixed into the soil when you dig the hole. Just like stared above it's not all that bad and palms like queens love water and don't mind that heavy soil at all. Add a good layer of mulch and you would be surprised how rich it gets in a few years. If you plant a healed dypsis or something like that it's best to amend and mound.

[Chester B]

I like to top dress with some nice light soil/compost, during planting.  Other than that lots and lots of mulch, 3 years in and I'm seeing inches of nice chocolate cake soil.  I'm expecting it to only get better with time.  I am also seeing so many worms where I had areas where there were none.

[Dartolution]

I typically use cyprus mulch in the yard. Is there one mulch or another you guys have found that is better?

[Chester B]

I think mulch is geographically dependent. Out here the mulch is from fir. 
 

The best mulch you can get for free usually. It’s the shredded material from landscape companies or the city. It has fresh green material in it too and breaks down nicely but not the most aesthetically pleasing. 

[OC2Texaspalmlvr]

I have had alot of trouble with root rot from our gumbo clay out here so I started using the mound technique. My raised planter palms have faired much better then the normal technique of palm plantings. Adding sand to your native soil would help with drainage too. 

[Tyrone]

The problem with clay soils is the fact that they can be low in oxygen content. Roots need oxygen to live. If you can deep rip and mix in large amounts of compost and organic matter you will improve the soil. Once microbes and worms get into the mix then it will come to life. Clay holds large amounts of water and nutrients but it also holds onto them stronger than a sandy soil would. Adding mulch and organics is the only practical thing that can be done. If you have a dispersing clay you can add gypsum which will help the clay clod up and drain better. Non dispersing clays don’t respond to gypsum. In heavy clay soils I would plant on mounds and use heaps of organics. Adding sand doesn’t really work unless you add 3 or 4 times the amount of clay with sand. Anything less than that makes sandy concrete.

[Silas_Sancona]

1 hour ago, Tyrone said:

The problem with clay soils is the fact that they can be low in oxygen content. Roots need oxygen to live. If you can deep rip and mix in large amounts of compost and organic matter you will improve the soil. Once microbes and worms get into the mix then it will come to life. Clay holds large amounts of water and nutrients but it also holds onto them stronger than a sandy soil would. Adding mulch and organics is the only practical thing that can be done. If you have a dispersing clay you can add gypsum which will help the clay clod up and drain better. Non dispersing clays don’t respond to gypsum. In heavy clay soils I would plant on mounds and use heaps of organics. Adding sand doesn’t really work unless you add 3 or 4 times the amount of clay with sand. Anything less than that makes sandy concrete.

Having spent time taking landscape certification courses sometime ago, learning the ins and outs of various soil types as part of the overall courses taken, let alone studying soil types extensively on my own.. Agree with @Tyrone  The benefits.. or negatives  of Clay based soils vary depending on region and composition.

Back in San Jose, you'd do almost anything to make the local, heavier clay soil there better.. can imagine that would be the case in other parts of the country where the Clay content of the soil is quite dense. In such cases, yes.. incorporating just some extra Sand can make things worse.. Here, while largely clay based, the soil in my yard is quite nice.. containing plenty of sand/ finer grit that it doesn't hold onto too much moisture for too long. Actually wish it retained more, particularly during the summer.  While not as easy to dig as sand, digging holes isn't difficult either.

Regardless, stuff grows pretty well without much input other than leaving what debris accumulates from the Mesquites above on it.  I might rake to clean up areas of the yard where i have rock mulch laid down, but usually leave much more organic material that has accumulated than what is removed ..or placed elsewhere. That said, a few years of heavy composting/ planting cover crops creates a nearly perfect, loamy / sandy substrate that everything thrives in.. or is what i have observed here.. 

On the other end of the spectrum, the Desert Southwest is well known for Caliche.. a dense, nearly impenetrable, & highly alkaline or salty type of soil / soil layer that can require the use of explosives to break through. While some plants thrive in it, certainly wouldn't be ideal for many other things..

[Really full garden]

When I lived in Houston my soil was a heavy clay that locally was known as gumbo.

I used rice hulls to help amend this clay and it took years! 

[Chester B]

I also do like to plant up higher as i add a top dressing and thick mulch layer so all of my gardens are at a higher elevation then when i first started.  I do also leave leaf and organic litter to break down.  I hope that once this starts to degrade that it will attract worms and increase their population so that they will help to mix into the clay.

[OC2Texaspalmlvr]

4 hours ago, Tyrone said:

Non dispersing clays don’t respond to gypsum. In heavy clay soils I would plant on mounds and use heaps of organics. Adding sand doesn’t really work unless you add 3 or 4 times the amount of clay with sand. Anything less than that makes sandy concrete

That is definitely good to know, cause adding sand was gonna be my next step to try and amend the soil some. I did get some Turface that I use for germination and potting soil. I'm sure that would help with clay amendment too =) 

 

2 hours ago, Really full garden said:

When I lived in Houston my soil was a heavy clay that locally was known as gumbo.

I used rice hulls to help amend this clay and it took years! 

You sure upgraded your garden setting !!! 

[Jeff985]

6 minutes ago, OC2Texaspalmlvr said:

That is definitely good to know, cause adding sand was gonna be my next step to try and amend the soil some. I did get some Turface that I use for germination and potting soil. I'm sure that would help with clay amendment too =) 

 

You sure upgraded your garden setting !!! 

Guatemala an upgrade from Houston... Can’t argue with that. 

[Dartolution]

The clay here is a deep red and very very dense/heavy. It WILL create a bowl in the ground if it is dug and left to fill with rainwater. When this stuff hardens it is as hard as concrete; taking a great amount of effort to break it apart. 

I believe It would be best to try and amend it with the use of a drill auger and perhaps gypsum or bark chips? 

My concern is it being too alkaline. Does gypsum alter the pH of the soil?

[Steve in Florida]

You don't want to add gypsum to acidic clay soils.  It is best for alkaline soils.  Try adding organic humus, pinefines, and leaf litter. 

[Allen]

Soil conditioner at Lowes is your friend during planting for mixing with soil to make it workable.  As is planting high or mound or raised bed.  Mulch heavy with mulch.

[RaleighNC]

I have spots in my yard where the clay is so hard and dense that barely any tree roots grow into it.  I try to dig deep and wide and add lots of organic matter of a range of sizes.  I mix in plenty of compost, commercial soil conditioner made from pine bark, as well as some larger chunks of pine bark mulch. If I only add compost, the soil is hard again in a couple of years. My aim with the larger pine bark pieces is to leave voids for drainage, diffusion of oxygen, and root growth even if the clay becomes compacted around it in the long term.  I also like Permatill as a more permanent amendment, but is more costly if you need to amend large volumes of soil.

[sonoranfans]

I think the term "clay soil" is not very definitive.  If your clay has a drainage problem, you will need to ammend and not just with organics.  Organics are digested and basically disappear over time making your soil return to its dense self.  Sand doesnt go away and pearlite(magic bullet for drainage) doesnt either.  They will prevent clumping of the soil.  ALso add 1/4-1/3 organic depending on whether mulch actually penetrates teh ground when you apply it.  If the mulch blows away or dries out before it goes into the ground it wont be ammending the soil unless you mix it in to the top 4" periodically.  In arizona the clay was tough, didnt drain well in some spots so I used big bags of pearlite, sand and organics and made a well with a radius of 2' for say a 15 gallon palm.  Root rot does hit some species harder than others and this you should realize when you place the palm and look at your drainage easement/low spots.  For washie filifera I'd put lots of pearlite in(1/5?) to make sure the soil breathes and I might plant it a few inches high with a paver border.  Some palms will take it and some will rot in soil that doesnt dry cycle deeply.  If you live in 9B or 9a you already cant grow 90-95% of palm species, letting your soil be continually wet will substantially cut down what is left for you to grow.  And a palm like washingtonia filifera will certainly have better cold tolerance when the roots dry cycle properly.  

[Dartolution]

Anyone have any advice for digging it up besides a good old shovel and pick axe? 

[Allen]

16 minutes ago, Dartolution said:

Anyone have any advice for digging it up besides a good old shovel and pick axe? 

If it's wet it will dig easily with a good shovel.  I do a ton of gardening and the best thing I ever did was buy a real shovel from Wolverine with solid all steel.  You can get one of those weasel type tillers if you want to mix in stuff but for small jobs not needed.   Mine is actually electric and it really works stuff over.  I just take the shovel and chop the clay into smaller pieces when the water consistency of it it right and add in soil conditioner and whatever else I want to make it manageable.

[Dartolution]

@Allen Im thinking that may be a better option. Digging it dry is impossible I know. 

[sonoranfans]

I would wet the area down slowly(a trickle) and dig a small hole.  Water wil fill the hole and penetrate down, refill till the area is good and wet.  When its wet it will dig with a pick axe and shovel.  that is what I did.  Dig to 3' depth or more to ammend.

[Dartolution]

Got out in the yard today since the weather has been nice, and starting digging a spot for a sabal I have that is in desperate need of planting (literally busted out of its pot). 

I took the advice here and got some gypsum, and soil conditioner from lowes and have been HEAVILY applying the gypsum and working it in best I can. 

Here is what I am working with:

This stuff is YUCK! Its hard dense red clay. The only reason I am able to dig into it as deep as I have is because we have had a very wet winter so far. 

Other than digging deeper down and amending it with soil conditioner and gypsum, what is do you guys think I could do to get this stuff broken up enough to plant a sabal and a mule palm in it?

 

 

[AZPalms]

Okay this is my two cents. We have different types of clay. I don’t have experience with red. I’d personally dig a nice deep and wide hole, amend with organic matter, perlite or something similar for drainage. Invest in a digging bar if needed. I’d also mulch/topsoil heavily. 

Here in AZ the soil is like rock. Heavy calcified clay/ hard pan. I was able to transform the native soil with mulch, compost, pine bark, worms, gypsum etc. now I have a nice grass lawn on what was concrete. Took about 3-4in of good topsoil and the rest tilled into the ground plus time and water. Now I can dig down and see healthy grass roots about a foot down into the soil. 

Mules, queens and Sabals aren’t too picky as long as it drains. I used the native soil lightly amended here when I planted. 

Edited February 10, 2020 by AZPalms

[Silas_Sancona]

8 minutes ago, AZPalms said:

Okay this is my two cents. We have different types of clay. I don’t have experience with red. I’d personally dig a nice deep and wide hole, amend with organic matter, perlite or something similar for drainage. Invest in a digging bar if needed. I’d also mulch/topsoil heavily. 

Here in AZ the soil is like rock. Heavy calcified clay/ hard pan. I was able to transform the native soil with mulch, compost, pine bark, worms, gypsum etc. now I have a nice grass lawn on what was concrete. Took about 3-4in of good topsoil and the rest tilled into the ground plus time and water. Now I can dig down and see healthy grass roots about a foot down into the soil. 

Mules, queens and Sabals aren’t too picky as long as it drains. I used the native soil lightly amended here when I planted. 

Mine is nearly the opposite.. Tougher to dig when dry but rarely too difficult. Very sandy but pretty good clay content. Almost reminds me of eroded Sandstone.  Drains well, too well when you want moisture to stay in the soil in Summer. Pretty sure this area of town was worked extensively in the past though which is probably a big reason my soil isn't as bad as it can be in other parts of town / the valley..  From what long time residents have told me, everything across the street from me / around the Hospital was Agricultural before being developed. There's also one remaining decent-sized parcel of land behind the neighborhood where Alfalfa is still grown. Were two until they built the apartment / hotel? complex that's almost completed. 

Far cry from the horrible, dense rock filled soil i grew up dealing with back in California. That stuff is even worse to deal with when really dense, less rocky clay is pulled up during construction and had been compacted by heavy equipment, especially if the layer is really thick.

[akamu]

Digging bars and pick axes help alot .  I removed a 50 ft pine tree and the soil was solid rock and clay around the stump it was very hard to dig so I went to the pawn shop and bought a small hilti jackhammer  with a shovel blade and it worked really good  as long as I didn't go to deep and get the shovel lodged into the ground. 

[Silas_Sancona]

Best hand tool ever :  solid steel Cap Rock Shovel, flat blade.. Not cheap, but well worth the investment.

[Butch]

I put in about 2' of commercial planters mix over the top of the clay in a raised planter... 20-25 CU YDs, if I remember correctly... It has performed well...

I also removed all of the clay for a depth of 5' to build a 5'W X 22'L planter in my front yard... I then put in this same planters mix... 22 CU Yds... Again, it did well...

Kind of extreme, but it worked for me... I have replenished this with more of the mix as it has broken down.... Lottsa work for an old 72 yr old man, to wheelbarrow this stuff from my driveway (Where the trucks dumped it) to the respective planters...

[Fusca]

16 hours ago, Dartolution said:

Got out in the yard today since the weather has been nice, and starting digging a spot for a sabal I have that is in desperate need of planting (literally busted out of its pot). 

I took the advice here and got some gypsum, and soil conditioner from lowes and have been HEAVILY applying the gypsum and working it in best I can. 

Here is what I am working with:

This stuff is YUCK! Its hard dense red clay. The only reason I am able to dig into it as deep as I have is because we have had a very wet winter so far. 

Other than digging deeper down and amending it with soil conditioner and gypsum, what is do you guys think I could do to get this stuff broken up enough to plant a sabal and a mule palm in it?

 

 

I feel your pain - this reminds me of my yard back in Georgia.  After a rain you probably spend as much time cleaning off the shovel as you do digging!    Then your tan colored carpet mysteriously turns red...

[RJ]

1 hour ago, Fusca said:

I feel your pain - this reminds me of my yard back in Georgia.  After a rain you probably spend as much time cleaning off the shovel as you do digging!    Then your tan colored carpet mysteriously turns red...

That is nasty red clay. When I lived in upstate SC I had that stuff. It sticks to everything and is nearly impossible to get off. Fortunately down here in the transition zone from the Piedmont to the coastal plain it's not nearly as bad. Our soil is more tan and rocky (quartz of all things).  The next town over from me is nothing but sand for the most part.    

 

I would be mound planting in that. Build a raised bed. 

Edited February 10, 2020 by RJ

[Dartolution]

6 hours ago, Fusca said:

I feel your pain - this reminds me of my yard back in Georgia.  After a rain you probably spend as much time cleaning off the shovel as you do digging!    Then your tan colored carpet mysteriously turns red...

 Well, I have bamboo hardwood flooring, but its just as bad haha. 

Alabama is currently under severe flood advisories from the store system moving through. The hole I dug (about a foot deep) is completely filled in water. 

The good thing however is, that I was able to take my garden drill auger and drill down another 1.5 ft in several spots... in the mud... the red thick mud... haha 

Still no drainage. 

Its basically a bowl of water in the ground.

[Dartolution]

23 hours ago, AZPalms said:

Okay this is my two cents. We have different types of clay. I don’t have experience with red. I’d personally dig a nice deep and wide hole, amend with organic matter, perlite or something similar for drainage. Invest in a digging bar if needed. I’d also mulch/topsoil heavily. 

Here in AZ the soil is like rock. Heavy calcified clay/ hard pan. I was able to transform the native soil with mulch, compost, pine bark, worms, gypsum etc. now I have a nice grass lawn on what was concrete. Took about 3-4in of good topsoil and the rest tilled into the ground plus time and water. Now I can dig down and see healthy grass roots about a foot down into the soil. 

Mules, queens and Sabals aren’t too picky as long as it drains. I used the native soil lightly amended here when I planted. 

Ill have to amend. It does not drain. Well, it does, but it takes forever... 

We have rain for the next several days and flooding... Ill be interested to see how quickly this crap drains ager the monsoon passes. haha

 

@Butch you're property looks great! I wish that was an option here, I certainly would do just that. However I fear that it will come down to me, a shovel, a pick axe, and time.

 

 

What I can say is that once it is water logged it DOES turn into red silty mud. I don't know if thats a good sign or not? What do you guys think?

Also, does anyone know if you can add too much gypsum? Because at this point Im not above pouring the entire 20 lb bag into this hole and tilling it up.

[Silas_Sancona]

20 minutes ago, Dartolution said:

What I can say is that once it is water logged it DOES turn into red silty mud. I don't know if thats a good sign or not? What do you guys think?

Also, does anyone know if you can add too much gypsum? Because at this point Im not above pouring the entire 20 lb bag into this hole and tilling it up.

If it turns to essentially a really fine muddy silt when waterlogged, that's definitely not great.. Means there is little to no pore space between clay particles as it settles / compacts. May stay too wet and not allow enough Oxygen to penetrate through it.  You've got a lot of adding organics ( compost, etc ), maybe something like paver base/ decomposed granite fines, ( or whatever is available there ) and Gypsum ahead.

Keep in mind the benefits of adding Gypsum take time, and you have to add more, over a 2-3 year period, for it to really help correct clay soil like yours..  

[Brad Mondel]

My soil is exactly like this and I am having issues with drainage and flooding. I have planted everything a little high and put several inches of mulch on top.  Hopefully this will be good enough for the palms.

[joe_OC]

On 2/10/2020 at 8:30 AM, Butch said:

I put in about 2' of commercial planters mix over the top of the clay in a raised planter... 20-25 CU YDs, if I remember correctly... It has performed well...

I also removed all of the clay for a depth of 5' to build a 5'W X 22'L planter in my front yard... I then put in this same planters mix... 22 CU Yds... Again, it did well...

Kind of extreme, but it worked for me... I have replenished this with more of the mix as it has broken down.... Lottsa work for an old 72 yr old man, to wheelbarrow this stuff from my driveway (Where the trucks dumped it) to the respective planters...

Good looking garden, Butch!  You put me to shame...No more excuses.  Time to place that 7 cubic yard of mulch!

[Tyrone]

There's probably good minerals in that red clay. Just got to break it up and get some air into the mix. If you can get worms into it and some organics then roots can get in there too.

Soil is quite a complex thing and I doubt we fully understand it. Although when putting organics into clay soils some of the organics will disappear over time, not all of it will. The microbes and organisms promote better soil structure which at the end of the day is what you want. You kind of want to create a friable loam to make a good soil. That is the aim whether you start with beach sand or solid clay.

[Phoenikakias]

On 2/10/2020 at 4:05 AM, Dartolution said:

Got out in the yard today since the weather has been nice, and starting digging a spot for a sabal I have that is in desperate need of planting (literally busted out of its pot). 

I took the advice here and got some gypsum, and soil conditioner from lowes and have been HEAVILY applying the gypsum and working it in best I can. 

Here is what I am working with:

This stuff is YUCK! Its hard dense red clay. The only reason I am able to dig into it as deep as I have is because we have had a very wet winter so far. 

Other than digging deeper down and amending it with soil conditioner and gypsum, what is do you guys think I could do to get this stuff broken up enough to plant a sabal and a mule palm in it?

 

 

Keep us apprised if the Sabal remains alive after two years!

[DoomsDave]

@Dartolution:

The great news is that clay is fertile. But as @Tyrone explains ably, it needs to be worked. Based on pictures you've provided you have clay much like I used to have. Like Janet Jackson used to say: "Nasty!"

The good news is you can improve it. The bad news, as you already know, is that it's going to be some labor.

I dug my place down two feet over a few thousand square feet, all by hand. That was nearly 20 years ago. It's so worth the trouble.

You can get a bobcat, or something like it, but the problem with those is they can pack the dirt down even worse. That said, with some planning a bobcat can work, especially if you or a good friend, is reasonably good at using it. (Avoid, say, denting a car, or knocking a hole in a wall.) Not like me.

My clay was nasty enough to make bricks with, and I went totally bananas and dug down 2 feet or so. Made a deep pit about 3 feet across by about 10 feet long, piled all that dirt to one side. After a while you get a system.

The key thing is to get as much cheap organic stuff as possible and mix it in. Dead leaves, chips from a chipper shredder, bad veggies from the fridge, nasty hay with manure in it, pine needles, twigs, bags of grass clippings, anything that is reasonably small that will decay fast. It takes a lot, and if you've never done it before, it will seem crazy, but remember this stuff will rot down to about a tenth its original volume.

I'd fill the pit with whatever stuff is handy (maybe a little fresh cow or horse manure, if possible); then toss in about half the dirt you dug out, then add more, and toss on the rest of the dug dirt. You'll end up with this layer cake mound that looks like a grave.

Repeat the process with as many pits as you can stand to do.

This is the perfect time, since the gym is closed, you can get your workout this way. Oh yeah.

Water if needed and wait. As the organic stuff rots, the dirt will sink. Sometimes it gets hot, and it's a good idea to get out there and turn it a bit. Over time those funky graves will settle a lot and you'll have dirt that plants will do much better in.

Essentially, the way I look at is that soil is kind of a crop, too. It's the result of biological action on all that stuff you already have and add. A lot of work. But, I promise you grow your soil, you will have a great garden.

There are faster ways, but the method described works best in the long run.

 

[Cluster]

What would you guys suggest for some volcanic clay soil with these rules: It already has stuff growing there, like bananas, washies, CIDP, King and Queens palms and it has a lawn covering  nearly everything (that is to stay). 

First question I searched and searched and it seemed to me, top dressing with compost was a good solution as it would not look bad on top of the grass, I heard it would take many years till the effect is noticeable though, but will it work over the years? 

Second question, for new plants, would it be worth to mix something inside the hole? I ask this because, image you get better drainage in the hole area, would that not become like a swimming pool seeing as the clay surrounding the hole would act like some sort of wall? 

Why is the soil a problem? Well bananas that would usually grow and fruit in one year take more than twice as much, a lot of things and palms grow there but they sometimes look a bit sad. 

What I can say is that compost made a difference right away on how the grass responded, one month after and it was deep green full o vigor, hopefully with more top dressing (and if you guys recommend something for new plants) all these plants will be able to thrive better without having to dig them out (well many of them are too big for that already). 

 

Thanks in advance.

[GottmitAlex]

Can't reccomend anything for question 1. If it ain't broken, don't fix it. Right?

 

For question #2: I'd add azomite and mycorrhizae.

I know, for many these are good as snake oil. But it wouldn't hurt.

 

 

Edited May 1, 2020 by GottmitAlex