Let’s talk Dirt(y)!
What is soil?
Soil is a mix of eroded rock and organic matter. Over millions of years rock breaks down to tiny bits and may mix with decayed organic matter. Organic in this sense refers to anything that was once alive. Very low organic levels result in sand or gravel, at the other end of the spectrum, high levels of organic matter and low mineral content result in peat, or compressed organic matter with very little mineral content. Neither extreme is very good for growing vegetables. Fortunately for us, most gardeners’ native soil falls somewhere between the two. According to Wikipedia, “On a volume basis a good quality soil is one that is 45% minerals, 25% water, 25% air, and 5% organic material, both live and dead.” Notice the inclusion of air and water. I think it is easy to overlook these as intrinsic components of soil.
It’s a living thing
Healthy soil is a living thing (cue the Electric Light Orchestra!). Full of microbes, bacteria, tiny insects, and worms, healthy soil is teeming with life. It not only physically supports your plants providing stability, it also supports your plants nutritionally with the micronutrients and trace elements your plants need for good health.
Drainage – neither too wet nor too dry
Drainage is important to good soil. It keeps plants from standing in water – a situation that can rapidly lead to root rot and plant death. You can improve the drainage of your soil by adding organic material, and by adding vermiculite/perlite. The organic material will “loosen up” the soil and the vermiculite will help retain moisture, releasing it as the surrounding soils dries out.
Improving on Nature
People can spend a small fortune and/or spend years trying to improve their garden soil. It is possible. Improving garden soil usually involves the addition of amendments. Here are the most common ones.
Compost
If you have time, you may add compost, leaf mulch or other decayed organic material to your planting beds over the course of several years. In time, you’ll have rich organic soil for your vegetables to thrive in. A single truckload of compost dumped into your beds will improve them, but the real benefits won’t be felt for several years of continued improvement.
Most people I know are impatient and don’t want to wait several years, let alone one growing season; especially when just getting started. I recommend jump starting your garden with purchased compost and simultaneously starting a compost pile. 
Whole books are devoted to compost, as the joys of composting are many and include reducing the amount of waste going into landfills, improvement of garden soil, fantastic results in garden production. Good plant based compost is a great addition to your garden’s soil.
I’ll cover composting further in a future article.
Aged Manure
Animal dung is great for your garden in moderation. Often you can get fresh manure free for the asking if there is a small stable or farm with animals nearby. They have to get rid of it or it just piles up.
There are two warnings regarding manure.
Fresh manure is too “hot” to apply directly to your vegetable beds. What does this mean? It means there is too much fresh nitrogen and it can damage or kill your crops. (There is one exception that I know of – rabbit dung – which can be directly applied to your garden beds.) Thankfully the solution is easy.
Use old poo.
Old manure has had the time for beneficial bacteria to break down the nitrates into nitrites that plants can use. Make sure the manure you use has been aging for at least 6 months or until it is dark and crumbly and not identifiable as manure. Alternatively, purchase your bags of manure from the gardening center. This manure has gone through the aging process so it is less likely to burn your plants.
Last year I added some horse manure that I thought had sufficiently composted. It stunted and “burnt” some basil plants early in the season. As the summer wore on, and more rain fell, this problem resolved itself, and the basil grew strong and healthy.
Be aware, composted manure is high in salts and over time, the salts can build up and be detrimental to plant growth. Be judicious in the use of manures.
Peat
For many years, people used peat as a soil amendment or conditioner to loosen up clay, or clumpy soil, or to add moisture and air retaining properties to garden soil. Peat is decomposed, compressed sphagnum moss. Peat is readily available and very effective as a soil conditioner. But there is a problem. Peat takes a long time to form, making it a resource that while renewable, may not be sustainable in the long term. It’s estimated two-thirds of all peat consumed is by amateur gardeners! Recently there has been more awareness of this and suppliers are working on alternatives. Coir or the husk fibers from coconuts hold promise as a sphagnum peat replacement, but as yet have not achieved wide spread use. It is however, what I will be using in the future.
Coarse Sand
Add coarse sand (.5mm- 1mm) to heavy clay to improve drainage. This works by adding open spaces, allowing air and water to flow more freely.
DIY or “make your own soil”
Some people will choose to amend the soil they have on site by adding amendments, that is manure, compost or coarse sand as mentioned above. In a boxed raised bed, if you choose, you can create your own soil!
Mel’s Mix™
Squarefoot Gardening instructs you to mix 1/3 by volume each peat moss, vermiculite, and manure. This is known as “Mel’s Mix.”™ Use care when choosing your manure as discussed above. Mel suggests you use five different kinds! This might be possible but I had a bit of difficulty finding five different kinds of manure. I used three with good result. I suggest letting this mix be a starting point, especially for beginners because it does work, and takes the guesswork out of ratios.
As I continue, I suspect the composition of the soil in my beds will tilt towards homemade compost and coir “peat”. I do have some coarse vermiculite left so that may go in as well. I also have access to horse stall muck, as well as chicken coop muck.
Testing
If you want to be sure about your garden soil and the nutrients it holds (remember plants drink, so water soluble minerals and micronutrients are sucked up along water in the soil) you can test it. I have never tested my soil and have had good results. That is not to say testing your soil is not worthwhile. Knowledge is power and if through testing, you find that your soil is grossly lacking in proper plant nutrition, then you can, (ahem), make amends.
There are two basic ways to test. One is to buy a kit and test it yourself. The other would be to send in soil samples to your local university agricultural extension for testing.
Kits
I’ve seen kits at the local growing centers and in the gardening aisles of the big box stores. A little on-line research will give you some idea of their usefulness.
Local university extension
You can of course take and send samples off to your university agricultural extension they will test it either for free or for a nominal cost.
Stay tuned, in the interest of science I’ll compare results between at least two soil “testers” and the results I get back from the local university.
Conclusion
Soil is the basis of a productive garden. Fortunately you can improve on what nature gave you or even create your own from scratch! Take care of this basic and most important element and you’ll be greatly rewarded!
Until Next Time, Keep Digging and Eat Well!
January 13, 2012
What informative and well written articles, David! Bravo!
The past few years I’ve been the “buy a yard of composted manure” type of gardener, but now that I’ll be home into the early winter months I will be able to rescue bag after bag of leaves that my neighbor sets out for the garbage collector! I may even be able to talk her into letting me run the mower into her back yard to chop and mix those fallen leaves with fresh grass clippings. In the past (when I had my own maple tree in the back yard) I would put a good layer of chopped leaves/grass on top of my garden, then cover it with a layer of manure and let it set all winter. I’d dig it under in the early spring, and my soil was lovely.
January 13, 2012
Hi Granny! Thanks… I’m surprised there are not commercial leaf compost products. If there are, I don’t know of them. I look forward to watching your “permanant” installation. BTW, I’ve read about using rabbit (alfalfa) feed as an activator for fall leaves. It sounds like and easy method and one I may try.
January 13, 2012
David, I always use rabbit feed (alfalfa pellets) as a slow release nitrogen source in my lettuce bed. It’s pretty cheap at about $10 for a 50 pound bag at the feed store. When I was doing the leaf and manure sandwich, I used a very light sprinkling of lawn fertilizer, which was probably straight nitrogen between the layers. I haven’t used lawn fertilizer in years though, as we now mulch our clippings and find no need for it, and would now hesitate to use a non-organic source for the nitrogen. A sprinkling of pellets would be a great idea, although probably much slower acting.
Warning…do not put alfalfa pellets in your indoor growing medium. I thought it would be great to add it to my potting mix for starting seedlings, It stinks to high heavens as it rots/ferments!
January 14, 2012
Thanks for the tip!
January 13, 2012
I’m very much in favour of home-made compost, though it does take time to establish a good “production line” for it. I have three plastic bins in use – one for leaf-mould and the other two used in rotation for general compost. I still have to buy compost for my containers though, and I use the home-made stuff as a booster for the raised beds.
January 13, 2012
Mark, do you work the home-made stuff into the beds or do a top dressing or both?
January 14, 2012
Thanks, David. This is a great post! This year, I think I’lll give Mel’s Mix, or as your suggest, a variant, for my containers. Many years ago, Grandpa had a farmer friend who suppled him with all the manure he needed. We boys absolutely hated “manure weekend” and would do our best to make ourselves scarce when we saw Grandpa getting things prepared. It never worked. Where is a 12, 13, or 14 year old boy going to hide, especially when all of the adults knew you’d be “called into service” Saturday morning? 🙂
January 14, 2012
Great story John! Funny how things change. My mother had a small garden and I hated to go go out and weed. As a child I wanted no part of gardening. And now!?
January 15, 2012
Hi David,
Many thanks again for leaving such a kind comment on my new blog site. I am fascinated by yours-really, really informative and I shall look forward to following it.
I lived in Wisconsin for a year-about two and half hours north from Chicago- and still visit now and again so well remember the cold, all that snow and then the heat in the Summer… The delicious produce from the garden though, was abundant and varied-happy memories!
January 16, 2012
Thanks for coming by Green Dragonette. Were you near Madison? You’re right the extremes can be well, extreme!
January 15, 2012
I was interested in hearing that many types of manure should be used. I will try to remember that when I am getting manure this spring.
As kids we hated weeding as well and we really hated rock picking but I still loved gardening even then.
I remember an very old lady I used to visit telling me about how they had kept putting leaves in the garden until they had good soil. I hope it works with mine.
January 16, 2012
I was too Becky and I’m not sure it is necessary, but in a way it makes sense, diversity is a good thing, especially when iot comes to gardens and ecosystems. If you were to use only one type of manure an d there were something off… well it would impact the whole garden. I agree the leaves would over time improve the soil.
January 16, 2012
Hi Dave, great post about soil. So important. After becoming an Extension Master Gardner I highly recommend the Extension soil testing. (see the bias?) Another very important reason to use matured poo is disease. In our time of e.coli break outs it is recommended to let manure mature 4 to 6 months before veggies or fruits are picked around it. So if you use it for side-dressing it is very important to wait 5 months. All the wait times are based around temperature and climate, if its cold you need to wait much longer. There is easy access to articles about the typical N-P-K levels in different animals poo as well, it might be helpful if you are trying to amend your soil. I am a composter, but a lazy one and I have the space and time to be lazy So I don’t mix to much. Thanks for another great post.
January 16, 2012
Hi Spencer, thanks! I didn;t know you were a Master Gardener! Cool! I’ve thought asbout it buyt don;t have thge time to commit just yet though I suspect inthe future this will be on the agenda. I too am a lazy composter! I’ll be covering compost further in a future post.
January 17, 2012
Excellent post, so many people I talk to find it hard to grasp the living aspect of good compost. I treat it a bit like making yogurt, when I make a new batch I use a part of the old one as a starter because it has so much life going on in it and will give a head start to the new batch.
I’d like to invite you to add your garden to Folia the (free) gardening website. It lets you log plants, gardens, milestone events like budding, flowering, changing colour, harvesting and many more. You can journal your garden, or even individual plants and keep tabs on your seed stash. There are wishlists, seed swaps, gardening groups (including foodie groups) and much more and you can view who else is growing the same plant around the world.
It’d would be great to see you there. Here is a link to it: http://www.myfolia.com/gardener/CDfolia/invite and my own gardening page (tracking 800+ plantings) is under member name CDfolia if you want to get a feel for the scope of it.
January 18, 2012
Hi Cally, Thanks for the tip about using some finished compost to incoculate the new batch! Great idea!
January 17, 2012
From what I’ve heard, sandy loam soil is a great, if not the best, growing medium. It is because of the oxygen exchange ratio, organic matter, and moisture holding capacity. I got this info from “the garden master”. What is your take?
January 18, 2012
Howard, great question. Sandy loam is considered one of the most desirable soils for gardening and planting; so the short answer to your question is yes, yes, yes, and yes. Sandy soil (coarse sand, not fine beach sand) while having excellent drainage and air space properties, lacks the organic nutrients to be very fertile. Loam soil is defined as having equal parts sand, silt (organic matter) and clay. If you add coarse sand ( or are blessed to have this naturally) to loam the you’ll end up with soil with good air pockets, high organic matter and excellent drainage. As with any soil, compaction is the enemy, once you get your beds how you want them don’t walk in them !