\u2022 It aerates the soil deeply and so increases the\nactivity of soil life and the subsequent release of nutrients.<\/p>\n\n\n\n
\u2022 It allows you to enrich the soil to a much greater\ndepth than normal (effectively making the topsoil deeper). This means you can\ngrow plants closer together, thus obtaining higher yields from a given area.\nThis is one of the keys to intensive cultivation.<\/p>\n\n\n\n
\u2022 It improves drainage\nand hastens the warming of the soil.<\/p>\n\n\n\n
\u2022 It is the most\neffective way to deal with compacted soil layers.<\/p>\n\n\n\n
\u2022 It enables you to\nmaximize inputs of fertility for the most highly intensive food production\npossible.<\/p>\n\n\n\n
The annual cultivation puts extra air into the soil and so\nstimulates the growth of decomposing organisms in the soil. These make\nadditional nutrients available from organic matter. <\/strong><\/p>\n\n\n\n Disadvantages<\/strong><\/p>\n\n\n\n Double digging can be hard on the soil in\nthat the repeated disturbance damages soil structure, destroying the tunnels\ncreated by worms and often inverting soil. Earthworms don\u2019t like it, as it\ndisturbs and may physically injure them. <\/p>\n\n\n\n The additional air in the soil speeds up the\ndecomposition of organic matter, so you must add more annually to prevent this\nbecoming a problem. <\/p>\n\n\n\n \u2022 Creating\nthe beds can be hard on your body and if you are not careful it can result in\nsome medical bills<\/p>\n\n\n\n Is it worthwhile?<\/strong><\/p>\n\n\n\n There is\nsome debate as to whether double digging is really worth the effort. Some\npeople point out that in a rich soil, most of a plants feeder roots will be in\nthe top 6 – 12\u201d of soil and say that it isn\u2019t really necessary to dig any\ndeeper than that. However research has shown a definite increase in yields\nafter double digging, an effect that lasted for several years. This is mainly\nbecause roots were able to penetrate more deeply in search of water in times of\ndrought (double digging is of great value in dry areas). The increased oxygenation may also increase\nmineralization and so make plant nutrients more available.<\/p>\n\n\n\n Whether it is worthwhile to double dig largely depends upon you and\nyour soil. It is most valuable on heavy or compacted soils (those that are\nhardest to dig), as it opens them up and allows you to get organic matter down\ndeep. Light soils can also benefit in that it allows you to incorporate organic\nmatter deeply, but they are usually already well aerated. <\/p>\n\n\n\n Though your vegetable garden might benefit from an initial double\ndigging, you don\u2019t usually need to do it routinely. It would not only be a\nwaste of time and energy, but may even have some negative effects on earthworms\nand other important soil organisms. I haven\u2019t double dug a garden for years\nbecause the topsoil in my present garden is loose, very deep and fertile.<\/p>\n\n\n\n If you are unsure about\nwhether double digging is really necessary, you could try an experiment.\nPrepare one bed by double digging and another by your favored alternative and\nplant the same crop at the same end of both beds. Then watch how they perform over the growing season.\nThis will give you a better idea as to whether it is worthwhile than anything I\ncould say. <\/p>\n\n\n\n H<\/strong>ow to double dig<\/strong><\/p>\n\n\n\n The tools for the job<\/strong><\/p>\n\n\n\n Double digging is hard enough without trying to do it without the right\ntools, so make sure you have a good sharp digging spade and a strong garden\nfork with handles that are long enough to be comfortable. In heavy soils you\nmight use the fork for double digging in preference to a spade (ideally a flat\ntined spading fork). See Tools<\/strong> for more on these).<\/p>\n\n\n\n Doing it<\/strong><\/p>\n\n\n\n In\ndifficult soils, double digging a large area can seem like a monumental task.\nExpect to take four hours to dig a bed 4 feet x 25 feet, though you could do it\nin half that time (or less) if you are strong and experienced.<\/p>\n\n\n\n 1) Start double digging by\ndigging a trench 10 – 12\u02dd deep by 18 -24\u02dd, wide and the breadth of your bed. If\nyou are only digging one bed put the soil from this trench into a wheelbarrow\nand take it to the other end of the bed (you will use it to fill in the last\ntrench). If you are digging more than one bed simply put it to one side and use\nit to fill in the last trench on the next bed (start that one from the opposite\nend). Remove any roots, large rocks and perennial weeds as you go (be thorough\nas this is important).<\/p>\n\n\n\n Some people double dig from\nthe side to avoid compacting the soil, or they stand on a digging board (a\npiece of \u00be\u02dd plywood 2\u02dd x 4\u02dd). You can also just stand on the bed, as it\u2019s going\nto be dug anyway.<\/p>\n\n\n\n 2) Put a layer of organic\nmatter (fresh or aged strawy manure, compost, inverted sod or surface\nskimmings) in the bottom of the trench. This is a good place to use immature\ncompost, or manure with lots of weed seeds, as it will be buried too deeply to\npresent a problem. Put some rock powders in there too (especially colloidal\nphosphate).<\/p>\n\n\n\n 3) Next use your fork to\nloosen the soil in the bottom of the trench. Make deep cracks 10 – 12\u02dd deep every\n3 – 4\u02dd all the way across the trench. Don\u2019t pulverize the soil to a fine tilth,\nor it may compact again more quickly. <\/p>\n\n\n\n 4) Start the next trench\nalongside the first, by sliding spades full of earth across to fill in the\nfirst trench. Try to keep these fairly intact, you don\u2019t want them to fall\napart. Also take care not to invert them, as subsoil is much inferior to topsoil\nfor plant growth. This can be a little tricky initially, but you will soon\nlearn how to slide, lever and flip the soil from one section to the next. In\nsandy soils the spades full of soil tend to break apart, unless they are quite\nmoist. In heavy clay soils you may have to break up the large clods with the\nside of the spade, otherwise they may dry out into hard lumps. The addition of\nlots of organic matter will eventually alleviate both of these problems. <\/p>\n\n\n\n If you invert the soil,\nputting topsoil underneath and subsoil on top, you are \u201cBastard Trenching\u201d,\npresumably done to make the topsoil deeper?<\/p>\n\n\n\n 5) Repeat these operations\non down the bed. When you get to the end of the bed, fill it in with the soil\nfrom the wheelbarrow (or from first trench of the adjacent bed).<\/p>\n\n\n\n Keep the edges of the bed\nstraight, otherwise plants at the edge of the bed may end up growing into\ncompacted soil. Compensate for any unevenness in the bed as you dig, by moving\nextra soil around as necessary, filling in low spots or cutting down high ones.\nIf you do this well the bed should be quite level when you finish, and should\nhave a fairly fine tilth that needs little further work. If the bed is very\nuneven you should rake soil from high spots to fill in the low ones (use a\nwheelbarrow if there\u2019s a lot to move).<\/p>\n\n\n\n When you finish digging, skim loose topsoil from the paths (leave the subsoil) and throw it onto the beds. If the beds are already high enough then don\u2019t bother with this.<\/p>\n\n\n\n Making digging easier<\/strong><\/p>\n\n\n\n The initial establishment of\na raised bed garden is quite a lot of work, especially if you intend to double\ndig many beds. In difficult soils, double digging a large area can seem like a\nmonumental task. Expect to take four hours to dig a bed 4 feet x 25 feet,\nthough you could do it in half that time (or less) if you are strong and\nexperienced. Fortunately there are ways to reduce the work (and the stress on\nyour body) to manageable proportions.<\/p>\n\n\n\n \u2022 Don\u2019t exert yourself\nany more than you would in your everyday life, or try to do too much at once.\nThis is especially important in spring when your muscles have weakened from\nwinter inactivity (this is the commonest time of year for injury). If you have\nany medical problems I suggest you avoid double digging altogether, as it is\nstrenuous. <\/p>\n\n\n\n \u2022 Double digging is hard\nwork, but it can be enjoyable if you work slowly and carefully. Dig only a\nsmall section at a time (perhaps 30 minutes a day), resting as necessary. I am\nfairly fit and strong and I find the repetitive hard labor of double digging\nquite therapeutic in small doses. More like a combined exercise and meditation\nthan an unpleasant chore. <\/p>\n\n\n\n \u2022 Break yourself in slowly and you will soon be able\nto double dig from dawn to dusk (or even dusk to dawn if you are particularly\ngung ho). <\/p>\n\n\n\n \u2022 Don\u2019t strain yourself by picking up more soil on\nyour spade than you can comfortably lift. Two small loads are a lot less\nstressful than one big one. You should also understand how your body works,\neven the strongest people can injure themselves through poor body mechanics.\nBend your knees when lifting, rather than bending from the waist (I admit this\nis one I have never quite got the hang of). Use your strongest hand to hold the\nbottom of the spade (where the weight is) and use your weakest arm to\ncounterbalance and maneuver it around. <\/p>\n\n\n\n \u2022 Dig efficiently. Jump on to the spade and use the\nweight of your body to push it into the ground, rather than trying to use your\narms and back. Use your heel or the middle of your foot to press down on the\nspade. Learn to lever and slide the spades full of soil into position rather\nthan lifting them (they break up less and it greatly reduces back strain). Push\nyour spade (or fork in heavy soil) into the ground vertically for deepest\npenetration. <\/p>\n\n\n\n \u2022 You don\u2019t have to dig\ndown the full 24\u02dd the first time. If it\u2019s a lot easier to only go down 15 – 20\u02dd\nthat\u2019s fine. You can go deeper next time, when the soil is looser and the\ndigging is easier. <\/p>\n\n\n\n \u2022 If you have enough\ntime you could plant deep rooted cover crops for a season to loosen the soil\nbefore digging (see below). This is a good argument for establishing the garden\nincrementally, over several years. <\/p>\n\n\n\n If you are not very strong and fit, you may want to spread this\ndigging over several years, doing 1 or 2 beds each year.<\/p>\n","protected":false},"excerpt":{"rendered":"![\"\"](\"https:\/\/greenmanpublishing.com\/wp-content\/uploads\/2020\/04\/doubledigall2-364x1024.jpg\")
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