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Too much organic material...

Posted by rkjones1953 10 (My Page) on
Mon, Dec 16, 13 at 16:13

I appologize if this is the wrong area to post but...
I made the mistake of building 16" raised cinderblock beds that contain approxiamately 60 to 70% organic matter. Worse garden ever. In the high desert I have water that will not drain and a swamp 12 inches below. I am thinging about adding another 8" of cinderblock and adding that 8 inches of sand to my organic matter. Anybody know if that might work. I did a tilth test and 90% organic floated on top. Any suggestions on a fix?


Follow-Up Postings:

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RE: Too much organic material...

How about some real soil added?


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RE: Too much organic material...

You mean locally purchased soil and not bulk planter's mix?
My intention is to mix this with the organic mix I already have and this would give me 24" of workable garden soil.


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RE: Too much organic material...

It will probably work, what zone are you in and what winter temps are you having? Im thinking that if you add a bit of granular nitrogen and keep your garden damp by april all that organic matter should decomposed, if you mix it with your existing soil Ill bet you will have a better garden this year, The sand wont hurt anything it will add volume and drainage and if I was a betting man youll have a great garden in a couple of years.

Merry Christmas


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RE: Too much organic material...

What you have probably is not all ORGANIC matter. OM will retain water but will never get soggy. OM is a cure for soggy/clay soil. Another thing, in a raised bed , 16" deep, it is very unusual to have water logged condition. UNLESS it is is raining constantly.
JMO


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RE: Too much organic material...

Optimal levels of organic matter in soil is in the 6 to 8 percent range, so I doubt that adding 8 inches of sand would be enough but it is worth a shot. You may want to look for a mix of the mineral components of soil that includes some clay and little to no organic matter, however, since the sand particles do need other, smaller, minerals to help the organic matter.


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RE: Too much organic material...

I appreciate everybody’s help.
I'm in zone 9a (92392 zip code/3,000’ elevation) one or two nights a year it gets down to 23 degrees. The norm is 30+ degrees F at night and 60+ degrees F during the day. Late July through August the temperature is 90+ degrees through triple digits. I live on the tip of the Mojave Desert next to freeway 15 after the Cajon Pass but before Barstow. We have dry winds that come from all directions because of the Cajon Pass and local mountains that surround our valley.
I have 5 beds. These are built out of 8"X16" cinder block. I used landscaping cloth on top of sandy/clay soil. I do not water during the winter so the soil does get bone dry for 6 months of the year and start my garden in May. (Not watering during our dry winters may be part of the problem.)
The bottoms of my raised beds get soggy because the water pours between the cinder block and organic material as I water. I get the top moist and as it begins to form puddles I move to another bed and then return to add more water. When water finally soaks in the top 3" I stop. The top 3" are dry the next afternoon but the bottom 6" is a swamp. Heat + Water + Organic Matter =swamp. I'm thinking about poking holes in the landscape material to see if it eliminates the smelly swamp.
Watering my beds, adding 8 inches of soil, and nitrogen to counter act the nitrogen depletion due to all my organic matter should get me in the right direction.


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RE: Too much organic material...

You've added landscaping cloth and blocked off your native soil-- why?

Yes, at the very least poke holes in it, and even better get rid of the landscaping cloth altogether and mix your native soil in with the stuff you have on top of it.

There is often no mineral content in bagged "soil" -- it may just be composted forest products, so buying "soil" may not do you any good. The mineral content is in your native soil. If it is hard as a rock, then water it, dig with a fork as deep as you can (maybe only a quarter inch) then water again, dig again, etc, until you can mix it in with all that organic matter you brought in.

If you don't mix with your native soil, then I'd suggest you treat your raised beds as if they are containers, and seek advice for container gardening.


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RE: Too much organic material...

The landscape barrier is to keep roots from very invasive bushes and trees out of the planter bed.
I was attempting to create a sandy loam soil but became organic matter greedy along the way and attempted to make loamy soil. The mixture should have been 20% regular soil clay, 50% organic matter, and 30% sand. The sand would provide the drainage; the soil/clay would be a reservoir of minerals, bind with the peat and sawdust, and help hold the moisture. The organic material is way to fine and overtime the course material has separated to the top leaving a thick layer of peat moss that acts as a water barrier until it becomes saturated. When the organic matter swells it decreases aeration.
Based on my readings and the suggestions offered, I need to add sand for drainage and clay for holding in minerals. Replace nitrogen because the organic matter depletes it although Nitrogen needs to be usable for plants. The peat and saw dust will bind with the soil/clay and probably provide more even moisture.

This post was edited by rkjones1953 on Tue, Dec 17, 13 at 15:13


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RE: Too much organic material...

If you used finished compost, it won't deplete nitrogen, but if it was compostable organics, it could depending upon the mix of greens and browns and resulting CN ratio. Which was it?

The level in the bed will almost certainly decrease as it continues to decompose, even if it was 'finished' compost.

Clay underneath could certainly explain the swampy effect - water pours right through the organic layer and sits on top of the native soil.

If you can get some local topsoil, bulk or bagged, or any soil with a reasonable sand/silt/clay distribution, and mix it in to all that compost, you'll have good stuff. It doesn't have to be a quality organic topsoil or garden soil, since you already have an abundance of nutrients and OM.

The comment above about bagged soils not having mineral content (soil) in them is *sometimes* true, and the opposite can also be true of cheap bagged compost products. Always investigate what's in the bag. Some composts I have tested have come in at <10% organic matter, indicating they were nothing but topsoil.


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RE: Too much organic material...

I believe you need to get your organic (biological) activity going and for that you'll need to make sure it is watered but not soggy. You don't want it saturated or you'll probably get destructive anaerobic fungus growing. Do a search for something like "break down the tough fibers in roots" and you should find some products that promote the biological activities for even the toughest organic matter. I agree with 6c-zr1 that some granular nitrogen will help because it feeds the biology. I also agree with elisa_Z5 about getting rid of the landscaping cloth and mixing native soil with the compost. A big problem with compost is that the bacteria and whatnot that are in the compost use all their energy on breaking the compost down and that robs energy from their relationship with plants so your garden suffers until the organic debris is digested. But once it is broken down it is your gardens best friend.


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RE: Too much organic material...

Building super-high beds and filling with bought materials so often seems to have this result.

If you have the room take way the blocks, rake the fill off the fabric and pull it out of there, and then dig the bought material into the native soil as best you can.


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RE: Too much organic material...

I'm quite concerned about the tree roots that you mentioned which you think will rob the nutrient under the bed you made. How far away you bed is from all the nearby trees? If the distance is not far enough(like less than 10 meters) then you will still have the tree roots to deal with after the problems of the bed were solved. Trees are like the enemy of vegetable gardeners. It is a real challenge to grow successful vegetables near any tree.


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RE: Too much organic material...

Actually I often get pole beans to grow up fruit trees.


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RE: Too much organic material...

I would rather have tree roots, than an unproductive garden. I am with pnbrown that fruit trees are not the obstacle. Here in the High Desert of California, they provide the partial shade needed to not burn your vegetable plants. I have bushes and tree roots that grow under a 4' retaining wall and travel more that 30 feet to get to a water source.


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RE: Too much organic material...

You might want to give a water penetrating agent a shot. It will help drive the tree roots down further in the soil where they are not competing so much with the rest of the garden.


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RE: Too much organic material...

GrdnGreen, please explain what that is. I have major tree root problems in my garden to the extent that I'm currently moving the beds, but it's only a matter of time until the tree roots reach them again.

The type of tree also makes a difference. Silver maples have a very shallow and fibrous root structure that's aggressive, whereas more deep-rooted ones don't get into your beds as much. So I hear - I have silver maples. :-\


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RE: Too much organic material...

I'm currently moving the beds, but it's only a matter of time until the tree roots reach them again.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
toxcrusader,
There are ways to deal with surface tree roots invading your garden. It depends on how close your garden is to the subject trees canopy. But , lets say the trees or on east side of your garden.
-- Dig a trench on the east side of your garden(South to north direction).
-- cut the roots you encounter and possibly pull them out as much as you can. Once the roots are cut off from the mother tree, they will die.. And don't worry, the tree will live.


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RE: Too much organic material...

Oh, I can dig and cut and dig and cut, but they do grow back. :-]


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RE: Too much organic material...

In soil such as clay where water has a hard time penetrating it you can use a water penetrating agent which instead of changing the nature of the soil, it changes the surface tension of the water. This allows the water too get deeper into the soil and so the tree roots don't have to work to come to the surface for water. Your local nursery should be able to help you with specific products.


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RE: Too much organic material...

In clay soils that do not allow water to move very freely you could use a "water penetrating agent" which is basically soap that helps reduce the surface tension of water so it flows easier. That does not fix the problem and is only a temporary solution. That, however, will not keep tree roots from coming near the soil surface. Trees send roots out into the top 6 inches of soil for many reasons that may have little to do with soil moisture.
Organic matter, up to a point, is always a good addition to any soil but in excess it can create problems related to water retention. One reason why potting "soils" have vermiculite or perlite added to them, to provide drainage.
Many years ago, while on the local fire department on of the members came back from a training seminar and convinced us we needed to spend $45.00 for a 5 gallon pail of this stuff that would help water penetrate to the seat of a fire better, Then we found out that a $1.98 bottle of dish soap from the local grocers would do the same thing.


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RE: Too much organic material...

$2 per quart is almost the same as $45 per 5 gallons.


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RE: Too much organic material...

Maybe the suds would help smother the fire...ya.


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RE: Too much organic material...

Interesting idea, but we've got limestone derived clay from the surface down to bedrock, 10-20 ft. in most areas. Most of it is tan, but there are seams of gray stuff you could make a pot from. I don't know how much of this stuff it would take to treat several thousand yards of clay, or whether it would actually work. I work in environmental remediation around Missouri, and one problem we run into when trying to treat contaminants in the subsurface is actually *delivering* treatment chemicals into the clay. On a humorous note, the best way might be to wait till summer when it cracks open wide enough to lose small pets into, and just dump the stuff in. :-]


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RE: Too much organic material...

Personally if the beds were mine Id get rid of the landscape cloth, then take out a couple of blocks to get a roto tiller in there and work the organic matter in with clay and ill bet if you keep adding organic matter every fall youll end up with nice raised beds, you probably will only have to roto till just one year if theres no traffic on the beds.

In your climate sprinkle a little high nitrogen fertilizer in and take out you hose and your garden will self compost real fast.

just my opinion.


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RE: Too much organic material...

"I do not water during the winter so the soil does get bone dry for 6 months of the year and start my garden in May. (Not watering during our dry winters may be part of the problem.) "

Not watering for months may be a larger part of the problem than you realize. I had problem getting new compost wet but water ran through similar to your discription. The good folks here enlightened me to the fact compost becomes hyper____ somthing or other if it gets super dry. Weird but after you get it damp and don't alow it to get overly dry again,it is much easier to wet.


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