1
point
How can I amend heavy clay soil for vegetables

General   

My husband has pulled up part of the back lawn at our new house to make way for a vegetable garden. Unfortunately we have a heavy clay soil and water just pools on it when it rains making big sticky puddles. With the strange weather this year this seems to happening a lot and the soil is getting very compacted. Is there any hope for a fall vegetable garden or should I wait until next year at this stage? How can I begin amending the clay to make it more habitable for plants? What are the best things to add? Unfortunately we haven't gotten around to a compost pile yet as I know that would be good.


Posted by: Megan Long (3 points) Megan Long
Posted: August 15, 2013




Answers

3
points
Try some permaculture techniques.

1. Mulch! Get free mulch from tree trimmers and pile it on. Mulch immediately improves the drainage. I use as much as 6-12 inches, but only 4 inches under the canopy of a tree. The soil under the mulch will be much easier to work in the spring. Linda Chalker-Scott has a good writeup about the benefits of mulch.
http://puyallup.wsu.edu/~linda%20chal...

2. Lasagna gardening. Start creating layers of any organic matter you can find in your prospective garden area. Free coffee grounds from coffee shops, bags of leaves that you or your neighbors have raked up, straw from halloween decorations, etc. If you want to plant this fall, and if you are able to build up at least a foot, then you can plant in pockets of potting soil or compost.

3. Hugelkultur. If what you have are tree branches and prunings, you can make a hugelkultur bed. Pile logs and twigs loosely a few feet high, and cover with layers of organic material. Depending on your climate, you may be able to plant in it this fall, or you can wait until spring when much of it will have broken down.

4. Plant deep-rooted pioneer plants or cover crops. If you can plant at all, something like daikon will help break up the soil and create channels for water. Or plant something that will create a lot of biomass to feed the soil. For a cover crop, try a grass (rye, wheat, etc.) and a legume (fava beans, vetch, etc.). Grasses create lots of root mass and break up the soil, and legumes add nitrogen to the soil (if you cut them back before they set seed).

I have clay soil in my community garden beds. I never till. When I first got the garden 10 years ago, I dug around to get weeds out. Since then, I've added compost and other organics to the surface, as well as mulch. As far as I'm concerned, clay soil is great soil and is easiest to work with if you mostly leave it alone. I've established permanent garden beds and I never walk on the soil in my garden beds. I create an environment where worms can thrive, and I let them do the work of creating good soil structure. I never ruin the soil structure by tilling or needless digging. I dig only to add a plant. I also let the plant roots do the work of breaking up the soil. In addition, I never leave my soil uncovered. I help it hold moisture in the dry season by covering it with mulch (or plants) at all times.


Posted by: Tanya in the Garden (128 points) Tanya in the Garden
Posted: August 16, 2013


Megan Long commented,
Wow, thanks for the info Tanya!
over 7 years ago.



2
points
Working with clay can be an uphill battle. Even if you replaced the garden bed contents with sand and mulch, your bed would still be saturated with water after a good rain because they're still surrounded by clay. Dig a hole the size of a shovel blade and fill it with water, see how slowly it drains. That's your garden bed, but larger: a lot of sand and compost in a bathtub full of water.

For the quickest results, build a few raised beds. You'll have to import some clean topsoil (inspect it closely and make sure what you're buying isn't the same stuff you're already dealing with at home). Personally, I would take a quart jar (like a clean mayo jar or mason jar) with a lid, and ask for two cups of soil, please. 8-)

Take it home, mostly fill with water and shake continuously for a few minutes, then set it where it won't be disturbed, like a windowsill. The sand will settle to the bottom almost immediately because it's the heaviest. The silt will take about 5 minutes or more. The clay is the smallest and finest, and it could take a day or two to settle, and some won't settle at all. Anything floating up on the top is organic material like compost. The "ideal" type of soil contains about 40% sand, 40% clay, and 20% silt. (I've never had it myself -- I think it's just a rumor!)

Now you know how to do it, do the same with some of your own soil (take out the rocks and roots and other debris) and compare the results.

If the soil that you're thinking of buying is way off in any direction, it could be a problem -- esp if it looks like the soil you've got in your yard. Unless your 2-cup sample is short on clay... just add some of your own and mix it in. Don't let anyone talk you into something like a big load of spent mushroom compost*, you want real soil, maybe with some compost mixed in. Basically, look at it carefully and make sure see it looks better than what you've got at home.

*Some people swear by mushroom compost. This was usually a mix of straw, livestock manure, sometimes leaves, sometimes stuff like ground corncobs, and gypsum (for calcium). They compost it all together, then steam it and kill all the good micro-organisms, and grow mushrooms on it, usually with chemical fertilizers and sometimes fungicides and sometimes pesticides, and it tends to be high in salts; then they steam it again and sell it. If you want to add some to your beds next year, fine, but just add some to it, don't fill the beds full of mushroom compost.

And get your compost pile going so you'll have good stuff to add to your beds next spring.




Posted by: FussyOldHen (16 points) FussyOldHen
Posted: August 17, 2013




1
point
Consider all the work you've done as having made your garden foundation. Now add soil and compost 1/2 and 1/2. Get the garden soil and compost from the city or township where you live or landscaping business, etc... Just mix it together and if you live near a farm, ask the farmer for some aged manure. A local farmer (organic) near me gave it to me for free; I buy my eggs and milk from him. It will be fine for next year if you mix it in with the garden soil and compost. You don't need much... no more than 1/2 the amount of the compost (or soil). e.g. 2 wheel barrows garden soil + 2 wheelbarrows compost + 1 wheelbarrow of manure.

Aim for 6-8 inch of raised garden on top of the nice foundation you already made. You may need to double or triple, etc... the amounts depending on the size of your garden. Enjoy your garden next year. You can cover it with leaves that people collect in the Fall. Have fun! and enjoy all the vegies that will grow next year. Caution: plant only 2 zuccini and pick when 9 inches long. In the spring rake rows by mounding the soil, and you are set to plant.


Posted by: Joan Ribbons (4 points) Joan Ribbons
Posted: August 19, 2013




0
points
Clay's really good but the answer is money and loads of hard work. You need to turn the soil. Use a fork to dig up big clumps and leave in the sun to dry up. Then hit with a rake to break it up. Over time it will become easier to work with. Add horticulture sand - you don't need loads it's just to change its structure. Then add organic matter (loads) and dig this in... another way would be to build raised beds and top up with compost.


Posted by: Joseph rudwick (1 point) Joseph rudwick
Posted: August 15, 2013




0
points
take the fall off from gardening and work in lots of straw or sawdust and manure to compensate for the nitrogen loss. Clay is a poor base to start a garden in, you might find raised beds much easier to amend. Don't add sand unless you're able to replace at least 40% of the existing soil or want a future making bricks


Posted by: J.D. Archer (31 points) J.D. Archer
Posted: August 16, 2013


Lindsay McMenemy commented,
I could swear I read somewhere not to add sawdust as it takes a long time to break down. I will try and find the article I was reading recently, agree with you about taking the fall off and spending some time working on the soil though.
over 7 years ago.

J.D. Archer commented,
because of it's relatively high ratio of surface area to mass, sawdust and wood shavings will break down within a couple years. But a semi-durable organic is what will keep the soil aerated enough to give the roots space to breath and grow. The biggest problem with using so much of a carbon type organic is the loss of nitrogen due to bacteria that break down the wood
.

over 7 years ago.

J.D. Archer commented,
Just came back from having breakfast at my local diner. Had an interesting conversation with an old school farmer and he told me that using gypsum would loosen up your heavy clay. So I poked around and found confirmation on the net. Worth reading the article before you try it: http://puyallup.wsu.edu/~linda%20chal...
over 7 years ago.

Lindsay McMenemy commented,
great information there!
over 7 years ago.



0
points
My soil is heavy compacted clay at least six feet deep and we have heavy tropical rain most days (evenings and at night mostly). When we started planting, 100% of the seeds, seedlings and purchased plants died due to anaerobic fungi and bacteria.

I avoid digging but saw no choice to get started so we covered the ground with a 4 inch layer of rice hulls and coconut coir then dug it into the top 12 inches of soil. Both take a long time to rot down so they aerate the soil. I hope that by the time they rot down the good bacteria, fungi and worms will be taking over.


Posted by: Frank Woolf (1 point) Frank Woolf
Posted: September 1, 2013




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