Ammending clay soil

[DALION]

It is not a secret, if you've seen my past posts about my soil, that I have 80-90% clay if not more in my whole yard. I have dug down as far as 3 feet in two different areas and only found clay so it's safe to say my yard is a solid mass of clay. In the next couple months i will post pictures of the large and expensive landscaping project I have undertaken to take care of my cycads (since they hate cold wet roots) and my palms as well but this thread is about ammending clay soil so here goes:

If organic material decomposes over time, does it then mean that all the ammended soil will over time then only be slightly less clayey but still just predominately clay soil? And, if you bury tons of organic material into the soil to ammend and improve it , are you then in danger of trapping the gases that are released through decomposition and risk killing the plants you place there? I have dug holes in the yard were previous owners have buried organic material and that soil has a blue hue and smells rotten. It seems that since clay soil is so small that it can trap gases (or air) and the result would be anaerobic decomposition and a build up of methane gas. I'm no scientist and building raised planting beds are common among cycad collectors but I was wondering if palm people have had problems with ammending clay soil.

Leo

[MattyB]

Yes, Leo, that smell! Ahhhkkkk. I've encountered that at my old place, where old dead tree roots were burried deep in the clay and rotting. Smells awful. In my experience (and I'm no scientist) once you mix/til in organic matter, you've aerated the soil so that gas buildup isn't a problem. I'd speculate that if you mixed in organic matter and then let the site compact and decompose all of the organics without adding more on top as a mulch, then you'd be back at solid clay again after several years. But since you're a gardener I assume that you'll continue to add mulch throughout the years and that aerated and preammended soil will now accept all of the nutrients now filtering down through it, and it'll only get better and better as the years go on. If you're not doing it already, along with the organics, I'd add some different size/shape aggregates to your ammending, like coarse sand, pea gravel, etc. and definately add gypsum, it really helps.

[tinman10101]

Leo

I have clay in my whole garden when i moved in 3 years ago. I have amended with just mixing 50/50 of Kellog's Amend and my clay soil and it seems to be fine. Of course I dug down 3 feet and amended all my beds. I believe a lot of people are afraid of clay soil but I embrace it. Since I have clay, I water only every four to five days through drip. Even when its 110F and 15% humidity. I believe the rotten smell you are smelling in the soil is probably because the previous owner watered too frequently therefore allowing the stagnant water to pool up in the clay soil for way too long which will rot the soil. I am not scientist but that is what i think is happening.

I love my clay soil and my palms love it too. My water bill averages to about 35-40 dollars a month. I believe with clay soil, one should focus on the watering frequency much more. I do mulch every year as well and now when i drop in new plantings, the soil is very rich in my planters because of the amending and mulching.

Cheers!

Tin

[MattyB]

You're right about clay being a good thing, in moderation. Drip IS the only way to water on clay and I love that you're only watering every 4-5 days in that extreme heat! If you're truely saturated 2-3 feet down then no matter how hot it gets, it's not gonna dry out in a week, just ain't gonna happen. The tree roots are gonna dry out your soil more than transpiration through the surface.

[DALION]

Matt,

Me a "gardener?" I barely know how to cut the grass. I do know about mulch and the continuous process that mulching requires when dealing with clay. I can't wait for next month when I start trucking in soil to fill in my raised beds and get my plants in the gound. The gratification will not be too instantaneous but I do have many large palms and cycads that I'm hoping will make an immediate impact.

Tin,

I sure I'm not alone in saying this but Iwould love to see some pictures of the yard.

Leo

Fellow Non-Scientist Palm Lover

[Gonzer]

Clay actually holds more nutrients than either loam or sand. They're just not readily available due to the particulate size. Digging in copious amounts of humic materials will eventually cause the clay particles to flocculate (form individual clumps) after 2-3 years. It's by no means an overnight process. If you want to use Gypsum try using the coarse size, not the powder or the pelletized form. Organic humus and plenty of it, that's the ticket.

[BigFrond]

Hmmm... I believe you have the same soil as mine. It is like playdoe and you sink into the soil anytime there is rain. Mine was full of the bluish crap everywhere that I dug and it smells. If I dig a hole and fill it with water, the water will still be half full the next day. I hired landscapers to rotortilled the soil with admendments. It helped out a lot. However, it is still not great six inches down. What I should have done is to remove at least 1 to 2 feet of soil, then rotortilled and admend it and then layer good topsoil/compost on the top. My brother-in-law did it this way and it saves him lots of $$ in the long run and extra work everytime he planted anything.

I on the other hand will have to remove a few inches of soil to the side and then remove some of the crappy soil below, admend the soil before I plant anything. Then I'm left with extra crappy soil to remove or dump somewhere.

[DoomsDave]

Clay can be amended.

I had parts of my garden that were literally bricklayer's clay that hadn't been fired yet.

I dug down 2 = 3 feet and buried lots of organics and kept the area moist. The stuff rotted in a couple of months.

The catch is: (1) it's hard assed labor; and (2) you need LOTS of organics.

Simply breaking up the clay will help some, but it tends to meld back together again unless you put organics, plus gypsum (including old wallboard) or gypsite to help keep it broken up.

I can get away with a lot of plants in a small place because the soil is very nutrient rich, but they do suck up the water a lot . . .

[Gonzer]

The catch is: (1) it's hard assed labor; and (2) you need LOTS of organics.

The Man has Spoken the Truth..."So it is written, so it shall be done!"

(besides, Dave can get away with cussin' on the Forum, I can't)

[DoomsDave]

The catch is: (1) it's hard assed labor; and (2) you need LOTS of organics.

The Man has Spoken the Truth..."So it is written, so it shall be done!"

(besides, Dave can get away with cussin' on the Forum, I can't)

Hard-a$$ed labor . . .

[BS Man about Palms]

Search some old threads.. but time and nature are best. I Mulched heavily and mound plant.. when your palm wants more nutrients or moisture, it will send roots down to get it.

[Jastin]

I've seen many gardens with clay that look great. Brett from Mission Viejo has clay that after 12 years of mulching you can put a hose too and it drains fast, he has one of the best gardens i've ever seen. Think of soil as a home for all those beneficial insects. you have layers, the top being the best. your top layer is your "O" layer where all your air and organics are. then you have your "A" layer. This is your topsoil. Then you have your "E" layer. These are your most important layers. A lot of times in cities when the build houses they have to level and grade the land which screws up the soil, you've got heavy machines compacting the soil and on top of that they are scraping away those great layers that took many many years to get that way.

Ideally you don't want to disturb those insects and the soil. You have to be carful about adding sand to clay cause you'll end up with something worse than clay...plus you would have to add way too much sand to make a difference. My soil is sandy loam - 60% sand and 40% silt. Sounds good? Not at my place. I live on a slope and they had to cut 6 feet of soil just to make my place level so you can fill a hole with water and it wont drain...ever. I guess it would be good if I wanted to make a pond.

I would do what Dave did, dig down and mulch/compost. Then add raised planters everywhere. I've done that at my house and after 3 years i'm really starting to see a difference. My soil science professor ( i'm a hort major ) used to always say if you have ANY problems with your soil - add organic matter!

[MattyB]

I remember a discussion about growing a cover crop of deep rooting perennials or some disposable trees to penetrate into clay soils

[buffy]

I'd like to add another point. We have a lot of clay soil around here. If you also have lots of trees, be careful about tilling to amend the soil. Most of the tree roots are in the first two feet of soil. If you start digging a large area underneath some trees, you just killed most of your trees. It will take two years to discover that, but they're dead. I highly recommend top amending clay soils with mulches and composts. Plant material a little high. That's it. In time, consistent mulching will give you the soil you want. But don't kill your trees with the tiller.