Drainage vs Permeability. Whats the difference?

[MC Silver]

According to the USDA, I have Hallandale Series soil here in SE Florida. It says its poorly to very poorly drained soil but further down it says its permeability is rapid. Whats the difference? And how will my well-drainage loving palms react? 

[Looking Glass]

I wouldn’t worry too much about it, but rather, look at the soil in your yard and what base you run into when digging holes.  The soils of south Florida are highly variable due to major development over many decades.  You might be sitting on rich, black dredged swamp muck, or sterile sand, or amended soil, or construction debris, over a limestone ridge or a deep loose base, depending on the history of the property and specific location.   

I sit mostly on a raised coral shelf neighborhood with a base of pure sand on top of fossilized coral somewhere deeper below.  It drains crazy fast, like 36 inches per hour, and holds little water or nutrients.  For that, they recommend pounds of composed manure and soil additives per square foot if you want to grow things.  

You can also find mucky, poor draining, low spots where the marl was dredged up for construction, leaving behind the canal systems for drainage.  

As you head south toward Miami and beyond, a limestone base comes up shallower and shallower depending on your specific location, until it’s almost like a layer of porous concrete right below the surface   Near the ocean… more sandy,  out west.. more mucky and marly. 

[Kennythes]

I ran into this with my potted palms—stuff like perlite made the mix drain fast, but I still needed coarse chunks so water wouldn’t sit at the bottom and rot the roots.

[sonoranfans]

On 7/12/2025 at 1:41 PM, MC Silver said:

According to the USDA, I have Hallandale Series soil here in SE Florida. It says its poorly to very poorly drained soil but further down it says its permeability is rapid. Whats the difference? And how will my well-drainage loving palms react? 

I visited a 5 acre garden in that area and also Ken Johnsons farm in homestead.  The surface soil had lots of limestone which drains poorly and impacts soil pH as well.  The water lovers that like alkaline pH looked fantastic!  Cuban copernicias( bailey, fallaensis, hospita), Chambeyronia's and satakentias looked stunning!  Seeing this I put down dolomite for mine and I make sure the soil is moist.   Bismarckias didnt look so good in that soil, skinny trunks, smaller crowns than mine and they wobbled(moved) when I pushed on the trunk.  the surface of the soil was wet and ken told me his farm is almost always wet on the surface and 25''.  Ken had to use a jackhammer like t6ool for digging to plant palms.  I am going to guess that your soil is ideal for the aforementioned wet loving, alkaline preferring palms, and not so good for those that grow the deep roots.  But some areas in the yard may be different than others.  Some may have different permeability.  I do recall talking with Ken who related that Archontophoenix sp. don't do well down there and he suspected it was a soil pH thing.  The gardens I visited were gorgeous, plenty of palms to choose from.  I would talk to the locals to see what to avoid.    There is also the construction related modification of soil, they don't put slabs on sand, they like to put clays or rocky clays around the foundation to stabilize it.  The only way to tell is to dig the site and take a look.  I had one area where I had to dig through almost 3' of rocky clay to get to the sand in my yard.  My most recently dug hole for a satakentia shows the rocky clay with sand at about a foot deep.  Its a good site, I have planted two other satakentias in similar soil 6-7 years ago and they are growing like gangbusters, very happy.  Here is the  latest site I dug showing rocky clay on top and grey sand underneath.  

[Silas_Sancona]

3 hours ago, sonoranfans said:

I visited a 5 acre garden in that area and also Ken Johnsons farm in homestead.  The surface soil had lots of limestone which drains poorly and impacts soil pH as well.  The water lovers that like alkaline pH looked fantastic!  Cuban copernicias( bailey, fallaensis, hospita), Chambeyronia's and satakentias looked stunning!  Seeing this I put down dolomite for mine and I make sure the soil is moist.   Bismarckias didnt look so good in that soil, skinny trunks, smaller crowns than mine and they wobbled(moved) when I pushed on the trunk.  the surface of the soil was wet and ken told me his farm is almost always wet on the surface and 25''.  Ken had to use a jackhammer like t6ool for digging to plant palms.  I am going to guess that your soil is ideal for the aforementioned wet loving, alkaline preferring palms, and not so good for those that grow the deep roots.  But some areas in the yard may be different than others.  Some may have different permeability.  I do recall talking with Ken who related that Archontophoenix sp. don't do well down there and he suspected it was a soil pH thing.  The gardens I visited were gorgeous, plenty of palms to choose from.  I would talk to the locals to see what to avoid.    There is also the construction related modification of soil, they don't put slabs on sand, they like to put clays or rocky clays around the foundation to stabilize it.  The only way to tell is to dig the site and take a look.  I had one area where I had to dig through almost 3' of rocky clay to get to the sand in my yard.  My most recently dug hole for a satakentia shows the rocky clay with sand at about a foot deep.  Its a good site, I have planted two other satakentias in similar soil 6-7 years ago and they are growing like gangbusters, very happy.  Here is the  latest site I dug showing rocky clay on top and grey sand underneath.  

This ^ ...

Highlighted thoughts in particular:

Aside from the puzzle piece of climate,   Success ..or failure...  of a plant to adapt where planted  can be strongly tied to the prevailing soil chemistry in X or Y region, or even 200ft apart. = Much more important puzzle pieces.

Limestone derived soils = high levels of Calcium Carbonate and/or other stuff like Gypsum   ..are weathered by water pretty easily,   and often retain a lot of moisture after being moistened, esp. during cooler times of the year.   

Limestone- rich deposits can drain well if the chunkier / less weathered layer of Limestone / Oolite / Coraline Rock is deep enough ( Think a surface layer / jumbled outcrop of Oolite / Limestone Karst. ) that water can move down to a deeper depth where the finer, more moisture retentive stuff is situated. 

Soils weathered from other sedimentary types of rock like Sandstone can act in a similar fashion, though the reason(s) they can be moisture retentive may be different than why Carbon rich soils can ( retain moisture ).


Volcanics ( Lava, Rhyolite, Granite, etc ) = Typically, completely different chemistry profile,  often ( but not always ) more resistant to rapid weathering, thus  water will permeate deeper, faster through a deep deposit of relatively chunky, -but weathered- granite " soil "

Still, in some cases,  if you dig deep enough through that kind of stuff, you may still find water flowing in a dry wash weeks after any rain has fallen.. 


Clay itself is the finest sized particulate deposited in X, Y, or Z location after eons of direst or chemical weathering.. It and Silt are two different things ( Silt being larger is particle size than Clay,  ...but smaller than Sand )





Agree 100%,  Unless the property owner lucked out,   one might have to dig 2ft down past whatever the base material brought in for the home's foundation might be ( if different )  to access your actual " native " soil / get accurate readings of your soil that reflect it's natural chemistry profile.  Taking that sample from only a few inches / foot down?   ..may not cut it / be an accurate reading. 


From there, ..it's all about picking the right plant options, for the right place..  

....Unless one wants to spend all / a majority  of their energy constantly complaining about why Z or B plant isn't thriving / having ABC issue(s) with... Even though the climate seems to be a " perfect "  < Perfect =  No such thing / Doesn't exist >  fit. 

..Instead of having a thriving landscape w/ the least amount of trouble / constant time and $$$ to correct said problems / minimal ( at best ) complaints..

🤔

...Like the complain - free option myself.  


 

[TropicsEnjoyer]

On 7/12/2025 at 7:38 PM, Looking Glass said:

As you head south toward Miami and beyond, a limestone base comes up shallower and shallower depending on your specific location, until it’s almost like a layer of porous concrete right below the surface

lol when i lived in miami i couldn’t dig down a foot without hitting rocks 😂 it was so annoying having to get a pickaxe just to make any type of hole.

[JohnAndSancho]

This what I think of when y'all say Dolemite. 

 

But I've learned that when I plant stuff out, I add some garden soil to it even though my soil seems to be very fertile up until the layer of clay about 6-8" down. And we seem to have a relatively high water table based on how everything looks when we get a good rain. I try to go deep and break everything up since most of this land has been growing nothing but grass for decades.

As I plant out more, I'll learn more. This is an ongoing process. 

[flplantguy]

My soil is highly permeable sand, so it drains fast no matter what unless you get to the water table, where it can't drain further.  I would guess if you pile it up it drains out completely, but the water table prevents drainage at the normal location of the soil. Advice above is spot on too of course.

[Kennythes]

I had a similar issue with confusing fast-draining soil and actual permeability around my yard. Turned out the water was draining quickly from the surface but pooling underneath, messing with some of my palms. I ended up reworking the soil layers and reached out to emersonproservices.com—they helped figure out how to improve both things without overcomplicating it. Sometimes it’s just how the soil is packed below that makes a difference.