You only need to double-dig once.

If that.

So if double-digging is detrimental to the soil, how would one add amendments? Just pour them on top, maybe scratch them into the surface?

Strangely, for millions of years there were no gardeners to double-dig, and plants managed to thrive and evolve. Man can never do as good as job as Nature does in opening and aerating the soil with her microbes, worms, beetles, and myriad other creatures.

Turning the soil exposes new weed seeds, exposes subterranean organic matter (where it then starts decomposing and is lost), promotes soil erosion, and simply is an exercise for the impatient who require something to do all the time.

Now given that...it could be very useful to expose bermuda roots to winter temperatures if done during the hardest parts of winter.

Once the soil is built up into a good healthy soil and has an active Soil Food Web they will move any nutrients you put on the soil into the soil. Double digging is a lot of work, often unnecessary, and can move the aerobic Soil Food Web down below where they can survive.
Where soils are walked and driven on and get packed down tilling might be necessary, but if the planting beds are constructed in a way that no walking or driving on is done tilling is not necessary, providing adequate amounts of organic matter are in the soil.

This post was edited by kimmsr on Wed, Aug 27, 14 at 11:32

I read something about that rocking fork method in Mother Earth news a million years ago. In fact I think Jevons had a regular column in that mag, or else they did a big story on his methods.

Yep, the microherd will do the tilling for you, once you get some amendments down there initially. If you have heavy soil (clay), which I do, it's best to leave the porosity in place that is created by worms and insects boring through - 'secondary porosity'. When you dig this is all destroyed. I've got my beds raised up about 4-6" after 20 yrs of amendments, and I don't dig much except for tree roots. When planting individual plants like tomatoes, I just dig a hole and amend that, and mulch with compost and organic matter. The micro herd then incorporates that into the soil. When planting seeds by the square foot (or sq yard) I'll dig in compost very shallow, rake and smooth the bed and plant.

Thanks for the great responses here.

>I would then till the mixture once more,Renais1, what's the difference between the tilling you do and double digging?

So the recommended course of action would be to spread amendments over the top of the soil and let it be? And the microorganisms will do the work, even the heavy lifting like breaking up the large clumps of tomato roots in the soil? This sounds too easy. :)

By next spring, you won't be able to find those tomato roots (at least if they're under the soil).

The process is like a chicken laying an egg, looking under the chicken every five minutes, will not hasten the process and in fact may result in a broken or bloody egg.

I tilled the soil when I first prepared it so that I could kill the existing cover plants, and to begin to incorporate some of the organics into the soil so that soil critters would have an easier time getting to them. I used an 8 hp tiller so the tilling took very little time or effort compared to double digging. By tilling twice, separated by some time, I helped to insure that the old growth had been mostly killed.
Renais

Dead plant roots will decompose in place, leaving a network of tiny pipelines in the soil.

I don't mean to suggest you have to be a stickler about NEVER digging. Actually my experience was a gradual reduction in digging over time as the soil improved. And possibly as I learned about the importance of secondary porosity in clay soil. I have double dug my beds several times since I started 20 years ago, but won't do it anymore, except to get big tree roots out.

Double digging is tilling. Not all tilling involves double digging, though.

Read One Straw Revolution.
He calls it lazy man's gardening.

I do utilize using a potato fork some to hasten drying in the spring to less amended areas. Yes, you dig in 7 inches and rock or lift a bit. This can be VERY helpful when adding amendments or even rotted manure. It lets some of the added things trickle down lower.

Just today I used a tiller to better prepare a plot for seeding tillage radishes.

from this

to this, if you have easy access to organic matter, no till is the best, garden was watered once at planting.

Double digging involves bringing the subsoil up and mixing it with the topsoil, which is undesirable. You want all the fine particles that washed down into the subsoil to stay there, and to not be bringing them back up to the upper level where they then make it less aerated.

I thought that double digging does not mix the two.

I have seen some really lush weeds where there was some mixing by tiling.

Right now I'm very frustrated with double-digging. it's taking me too long. Even the areas that were worked last year are full of johnson grass stolons, bermuda grass stolons and field bind weed. The worst of the worst, right? And they go down more than 2 feet.

I'm giving up on digging it all, but will refrain to the planting areas and those areas will be pretty wide. When the other areas have become crowded at the surface, I will destroy that are by digging a few inches, but that's it. I can't do this anymore. I cover everything with hay that works like the back to eden gardening, but know that even a foot of hay won't stop these ! It will just take time. Some of my plants might be stunted from the undergrowth, but I don't have a choice?

UGH and a big UGH.

I have a Bermuda problem and I decided years ago I can't kill it by digging it up if the roots live a foot or more down in heavy clay. Control is the best I could do. I found a product last year, Bayer Bermuda Grass Control that is supposed to eliminate it after multiple applications w/o harming other turf grasses. I tried it on a patch of lawn last summer and it works. I will find out this spring whether it has detrimental effects on garden plants like strawberries and rhubarb, because it's all up in those perennials.

I, thankfully, live outside of Bermuda grass country, but we've got bind weed, brome grass, and Johnson grass, each presenting their own challenges. A heavy mulch - I use compost, grass clippings, and pine bark, and an occasional, judicious use of Roundup on the bits that make it through the mulch - makes my life a lot easier.

Hey, thanks. I hadn't considered roundup because I'm geared toward veggies, but I could paint some directly on the johnson grass. I just might do that. I get so frustrated because I get so close, but cannot get it all.

Keep in mind that the world Health Organization as well as the National Institute for Health have recently reported that Glyphosate products are carcinogens.

http://www.ncbi.nlm.nih.gov/pubmed/23756170

kimmq is kimmsr

That's overstating things a bit. The phrase used was 'probable' human carcinogen. So are a lot of other things we use, for better or for worse. I certainly limit my use of all chemicals (from pesticides to cleaning products) but sometimes proper use of a chemical is a good solution to a problem.

In my fairly extensive flower beds, I've been fighting bind weed and brome grass for years. I'll never get rid of it all, but I can get it to the point you have to go looking for it. The weeds have to struggle to get up through the mulch, so they have long, convoluted stems - expose that, spot-spray it 'pfft' and they die back to the ground. After a few goes, they die.

In the veggie garden, I just pull and cover whats left with mulch. This is also known as the "coffee / beer" method of control. Morning: grab a cup of coffee, go out and pull bind weed. Evening: grab a beer, go out and pull bind weed.

My sister rented a place on a small ranch in NM that had goats. A goat ranch. Her garden was next to the goat pen, so she would toss loads of bindweed over the fence. The goats would practically jump on it. I'm sure if she let them in the garden they would eat the entire garden, so she was reduced to tossing it over the fence. The goats converted it to fertilizer should could put back in the garden later. :-D