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clay alkaline

Posted by Clemmielover 5 (My Page) on
Sat, Jul 27, 13 at 10:08

I need advice on how to break up my clay soil.
So far I used a lot of mushroom compost and regular manure with small gravel but it's not enough for a proper drainage.
The water sits in the hole for about 20 mins before draining.

I'll have a basic soil sample taken next week but have already found out we have alkaline clay and I would like to keep this very simple.
We built a compost bin but have not started to produce any compost yet and I have to have all the roses, and I suspect the rest of the perennials dug up and re planted again by this coming Friday.
Thank you

Follow-Up Postings:

RE: clay alkaline

  • Posted by TXEB 9a (My Page) on
    Sat, Jul 27, 13 at 10:49

If you have alkaline clay, high in calcium, the best way to "break it up" is the addition of organic matter. Adding sand or gravel won't help much unles you add enough that the sand or gravel makes up a greater volume fraction than the base clay.

Adding organic matter (OM) has it's limits. In a cooler zone than mine, you might be able to hold as much as 10% by weight / 20% by volume IF you keep it well covered with a decomposing organic mulch. A couple of issues for permanent or perennial plantings are (1) soil stability, and (2) surrounding drainage.

If you overload the soil with OM (e.g. compost), then as it continues to decompose the soil will subside due to loss of the OM. In a permanent planting the only practical way to maintain the soil OM is via top dressing or mulching. So you are basically limited to how much you can maintain. Probably 16-20% by volume (up to 2" on top mixed into a 10" depth) would be the upper limit..

The surrounding drainage issue is the "bathtub effect". If you dig a hole or a deep bed in poorly draining clay, amend it well with OM or anything else to improve drainage, you just created a bucket of sorts in the ground - it will fill easily and drain poorly. Anything planted in that hole or bed will, be subject to the periodic filling of the hole, and the attendant slow drainage.

The overall preferred solution is to build up a raised bed with well draining soil on top of the native underlying clay . When water percolates through that it will hit the clay and any excess will move outwards along the interface. It doesn't have to be as deep as the planting -- 4-6 inches will generally do fine but you can go as high as you wish, so long as you keep the soil OM to stable levels and then maintain it with regular mulching. When you plant keep the top or crown higher than the raised grade by a few inches, then mound up the soil to taper to the surrounding bed surface. The bottom of the hole should extend into native soil by about as much as it sits above the interface.

In all of this, choose plants that grow well in your native soil.

This post was edited by TXEB on Sat, Jul 27, 13 at 13:06

RE: clay alkaline

Consider using raised beds.

RE: clay alkaline

Very informative but I'm afraid a bit over my head.
The raised bed will the project for the fall but meanwhile I just picked up about 3 cubic feet of composted horse manure.
I got 4 bags of pine mulch and am about to empty out every bed.
My thought was one bag of pine mulch for say 4 gallon of manure and the rest preexisting dirt. ?
I don't have much of a plan , just mix the composted manure (real dark, heavy from last nites rain and lots of straw breaking down already) with the existing soil and pine mulch. I'm striving for the gritty mix the roses arrived in.
I couln't find alfalfa anywhere but am planning on going to a feed store tomorrow.
Do I need to concern myself with afalfa mixed in to the planting dirt or can I just top dress with it this year?
I just finished prepping and digging 20 shrubs this week and theyr'e all coming right back up with every other perennial in the beds to assure even drainage.
I'm not likely to put off this task until I can find the alfalfa.. Does it matter much?
Have in mind that I'm such a newbie that I can barely keep up with lingo of you pro's. :)
Thanks for all the help!

RE: clay alkaline

Oh vey, I just found out what causes the new holes to sag like that, I had a closer look at the bags of manure I had my partner pick up on his way home, the bags are unfamiliar to me and when I read on the back it says composted manure and PEAT. This must be what causes the non existent drainage?
I can't believe it, I have peat everywhere! (I never mastered gardening with peat and now dread digging up the rest of my clemmies, I already counted two casualties).

RE: clay alkaline

  • Posted by ericwi Dane County WI (My Page) on
    Sat, Jul 27, 13 at 15:53

Peat can be described as "organic matter," and it will help alkaline clay soils drain better, if it is thoroughly mixed in with the clay. We also have high clay soil, here in Madison, Wisconsin. However, it is not pure clay, and it does drain to some extent. I am using native soil amended with peat moss to grow blueberries, successfully. With blueberries I have to be careful not to put down too much nitrogen fertilizer, and they must be kept watered during the summer drought season.

RE: clay alkaline

  • Posted by glib 5.5 (My Page) on
    Sat, Jul 27, 13 at 16:16

Peat is fine, and counteract the alkalinity. IMHO, a deep initial tilling of lots of uncomposted organic matter, whole leaves, kitchen scraps, etc., will give best results. Then mulch, or start beds.

RE: clay alkaline

  • Posted by TXEB 9a (My Page) on
    Sat, Jul 27, 13 at 16:54

Nothing wrong with peat. Given everything you say you're putting into the soil my concern would be that you may be going overboard on the OM. But since it is not clear at all how much of what you're adding, and how that's being added, it's simply a SWAG. Also be aware that manures can be potent stuff, and can bring with them substantial salt levels, even when composted.

RE: clay alkaline

Hi guys, I was hoping to hear back from you as I'm working outside. Sorry about being vague, I mixed 2 cubic feet of pine mulch with the dirt that now has peat in it, I lifted about 2 cubic feet and added only a 10 gallon tub with horsemanure.
I was going back and forward over whether or not to put the horse manure in the bottom of the holes as I keep coming across conflicting info about it. I'm pretty sure it is properly composted as it has no smell what so ever to it.
The hay I can find is still solid but really kind of broken down at the same time.
That's why I decided to add annother 2 cubic feet of pine mulch to my mix, hoping to err on the safe side...
I decided to hold back on the grass clippings for topdressing and it seems like the alfalfa is best spread on top as a ring around the plant.
It's clay alright but I'm not sure it's straight up clay, as I'm digging up my plants I notice the dirt is kind of crumbly so dumping all that down a few years ago must have helped somewhat. It's mostly 2 feet down it gets heavy going.
I have a old watermelon I haven't tossed yet and a few bananas, I mos def will put it down in the hole!
I been trying to go as deep as possible whenever amending and these rose holes are easy 3 x 3 ft.
I realize this is not half bad, despite all the double digging, I had a few plants I wanted to move and now I get to re arrange the constellation in my main bed, it's over cast and rather cool here for a few days and I'm counting my blessings.
I should mention most my DA's are grafted on Dr. Huey who's reportedly better quipped to break trough the clay and reach nutrients but I also have a whole lot more clemmies with a more fickle attitude towards clay.
Thank you for steering me right!

RE: clay alkaline

Where in the United States are you? That will tell us much more then the USDA Plant Hardiness Zone which covers a very wide range of soil types as well as growing conditions.

You need to get about 6 to 8 percent organic matter in that soil, not 2 cubic feet of a mulch which is not meant to amend a soil. Peat moss, expensive and a non renewable resource, can be used but needs to be in very large quantities. Never mix organic matter just into the planting hole since that can create an impervious pot from which water will not easily drain. However, 20 minutes is not a very long time for water to take to drain from a hole, a couple of hours might indicate a problem.

Here is a link that might be useful: The bathtub effect

RE: clay alkaline

I'm a hour west of Chicago.
I have to say I'm getting bit dis encouraged. I spent last night lifting three DA's and using the dirt amended with pine mulch,
I added that much in the hopes of assuring proper drainage, at least in the immediate area around the roots.

When I was filling the hole it took by far the longest to get up past the first 3 inches but when it was draining it took the longest to drain the lowest 2-3 inches. I find this bit of information somewhat contrary but it is beyond me what it really means.
Is there any significance to this ?
It actually took more like 45 mins for it to completely empty out;

Sorry, I don't have any way of determining 6-8 % of anything unfortunately.
Since I don't have any home made compost to add to the mix and it already had peat mixed in with the store bought manure I added some finely cut water melon rinds and a few banana peels before putting the plant in on the advice of a gwebber.

I'm so confused by the following : " Never mix organic matter just in to the planting hole since that can create an impervious pot from which water will not drain.

I can't even begin to wrap my head around what a
"impervious pot " is.
In this case the organic matter would be the rinds, bananas and horse manure?
Do I have to lift the roses AGAIN?

Let me ask this, am I in over my head here? I never did garden with roses and feel very much out of my depth, Most of the DA's are grafted on Dr. Huey who's supposedly well equipped to handle the clay...?
I think I need to stop fretting and leave them be, it's all so new I don't wanna go add alfalfa pellets or myrcozzial whatever it's called treatments without having a clue of what I'm doing.

Ideally, I get them to grow this year, I don't car much about their appearance as long as theyre healthy and doing their thing until spring comes around.

RE: clay alkaline

Perhaps these simple soil tests might be of some help.
1) Soil test for organic matter. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. Added note. You are most interested in what is on the top after allowing this to settle. That is the amount of organic matter in the soil.

2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains’ too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.

4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell.

5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

RE: clay alkaline

Maybe the info from Cornell linked below will be of some help. The first test kimm noted above is a good one for soil texture. Note the link within the Cornell article on "Using organic matter in the garden".

Here is a link that might be useful: Cornell - Soil Basics

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