Double Digging, The Gardener’s Workout
Ah, spring! The warmer temperatures and longer days will soon lead to…bikini season. Not what you expected me to say, was it! This is garden season, and there’s no time for the gym! Let me introduce you to the fabulous workout that will get you ready for both garden and bikini seasons. Double digging!
What is Double Digging?
Double digging is a technique for preparing garden beds for planting. It is one part of the method known as French-intensive gardening. Intensive gardening was first practiced by Parisian gardeners growing for market in the 1800’s, bringing together horticultural practices of the Greek, Chinese and Roman cultures. Through intensive gardening, these Parisian market gardeners could grow 100 pounds of produce annually for each person in the city! Intensive gardening techniques were introduced to the United States by Alan Chadwick in the 1930’s, and further popularized by John Jeavons (author of How To Grow More Vegetables and The Sustainable Vegetable Garden) and others.
What Are The Benefits of Double Digging?
The double digging technique has the most impact on perennial flowers and vegetables, because perennials are more deeply rooted than annuals. Double digging is especially beneficial to rocky or compacted soil. However the benefits are many for any plant, in any soil.
Double digging loosens both subsoil and topsoil. This aerates the soil allowing water, oxygen, and essential nutrients easily enter the soil, which results in much healthier and stronger plants that are resistant to various diseases. The loose, uncompacted soil also allows roots to grow and spread unrestricted. Deeply rooted plants are better able to handle periods of drought.
Here are summary of the benefits of double digging.
- makes the soil more fertile
- makes the soil to absorb more water easily
- allows more air into the soil
- keep the soil fertile for a considerable longer duration
- allows plant to grow deeper into the soil
- keeps the soil light and soft for longer duration
- dig once then do not have to dig again for about three to four years.
And let’s not forget, double digging gives you a good physical workout!
Before You Begin
There are a couple of situations in which double digging might not be for you. First, if you have back problems or other health problems that prohibit strenuous activity, don’t undertake double digging. No doubt about it, double digging is physically taxing. That’s not to say you can’t hire someone to do the hard part, while you supervise from under a shade tree sipping lemonade! Second, if you don’t have access to adequate organic material – compost or manure – then wait on the double digging until you do have these materials at hand. Otherwise all of that hard work will be in vain!
Take the time to stretch out as you would before any type of exercise. And expect to tackle this project over the course of several days. Don’t try to do the whole garden at once.
Do your double digging at the beginning of the growing season. Leaving the new beds sit naked over the winter will invite erosion and compaction.
One of the beauties of double digging is that no power tools are needed! You will need a wheelbarrow or garden cart, and a square spade. Be sure to get a long-handled spade if you’re over 6 feet tall to ease back strain. A pointed spade will work, but a square spade makes a more uniform trench. You’ll also want a board or plank to stand on, so as not to compress the soil.
Double Digging Technique
To begin, dig a 12″ wide by 12″ deep trench the length of the garden bed. Pile the topsoil you remove at the edge of the garden, or place it in your wheelbarrow or garden cart.
Once the top 12″ of topsoil are removed, start back at the beginning of the trench. Dig down and remove a spade’s width of the next 12″ of subsoil and set it aside for the moment. Now you have a spade’s width, 24″ deep section in the trench. Put a 2″ to 3″ layer of compost in this section of trench you’ve just excavated. You can use post hole digger.
Next move another spade’s width over in the trench. Dig out the next 12″ of subsoil there and shift it to the previous section, placing it on top of the compost you added there. Add a layer of compost to this second section. Repeat this dig-shift-compost step until you get to the end of the trench. At the end of the trench, add compost to the final section and cover with the first spade of subsoil you set aside at the beginning of the trench.
One variation on this method is to simply loosen the subsoil instead of removing it from the trench. Then, instead of applying compost in a layer on top of the subsoil, mix the compost into the loosened subsoil with a spading fork.
Either way, once you reach the end of the trench go back and add another 2″ to 3″ layer of compost over the subsoil along the entire length of the trench.
At this point there are a couple more variations. If you’re doing one trench at a time you’ll retrieve the topsoil you first took off the bed and place it back in the trench, on top of the second layer of compost. If you’re going to start a second trench, you’ll spade the topsoil off the second trench and place it on top of the first trench. Hold aside the topsoil from the first trench until you do your last trench, and then use it there to cover the second layer of compost in the last trench.
In either case, add a third and final 2″ to 3″ layer of compost on top of the bed after replacing the topsoil. Adding these layers of compost over each layer of soil will have the effect of raising your beds about 6″ above where they were originally.
Scrape soil off the end of the spade occasionally, and sharpen as needed.
When the bed is finished, rake the top of it flat and gently slope the sides. Plant immediately, if possible, otherwise mulch well. Plant intensively, in a diagonal pattern, so that all plants are spaced an equal distance from each other. The spacing should be such that when the plants are mature their leaves touch. This will cover the soil quickly, suppress weeds, and help retain moisture.
Some sources say double digging need only be done once. Others say it should be done every three to four years. But the only real year-to-year maintenance is simply to not walk on the beds. At the beginning of the next season, loosen the top soil and mix in compost as needed for whatever crop is to be grown there next in your rotation.
There you have it! A surefire workout plan that will get you – and your garden – in shape!