The pile on the left consists of aged wood chips — all that’s left of the great Northern Red Oak that once grew in my backyard. The pile on the right is a load of mushroom compost that was delivered about three weeks ago. Both sit on thick black plastic (tarps work too) to prevent plant roots from invading my supply of soil-improving goodness.
I can tell by the search strings bringing folks to this blog that many new gardeners are hoping to grow vegetables this year. Hurray, I say! And welcome to the sisterhood/brotherhood of folks who grow at least a bit of their own food. It’s clear you have many questions, and today, I wish to address one of the key factors that separates successful growers from black thumbs — soil.
Clay soil challenges
In the southeastern Piedmont region of the US, our native soils are mostly clay. Here in North Carolina, we call it Carolina Red Clay, although I hear folks in Georgia put their state’s name in front of the Red Clay portion of the moniker. Contrary to common belief, clay is not low in soil nutrients. If it were, our Piedmont native forests and fields would not be so lush.
But clay is not ideal when you want to grow vegetables. Veggies prefer loamy soils rich in organic material. The organic material improves drainage and the moisture-holding capacity of the soil. It also provides a home for the zillions of beneficial soil organisms that facilitate the transformation of soil nutrients into forms accessible to the root systems of veggies and other plants. Soil organisms range from visible participants, such as earthworms (You can’t have too many!) to beneficial fungi and bacteria. Healthy soil is jam-packed with life.
Invest in raised beds
In my decades of experience, the only reliable way to create rich, healthy garden soil from red clay is to add as much organic material as you can. To make this practical, you must create raised beds. Yes, this is hard work in the beginning, but once created, you will reap tasty rewards for decades to come. Trust me on this. Raised beds improve drainage and help you build deep, rich soils suitable for growing root crops like beets and carrots.
The raised beds in my garden don’t look very raised, because they aren’t enclosed by boards or stone. Wonder Spouse and I created them by digging out the paths between beds, adding that soil to the beds to make them higher. We fill the paths back up to their original levels with wood chips. The chips suppress weeds and act as a moisture reservoir from which plants in the beds can draw as needed.
I am an organic gardener. I think chemical fertilizers are always a bad idea, because too much of what is applied — especially to lawns — washes downhill and into our streams and water reservoirs. Most of what washes is excess nitrogen, which creates massive disruptions in the ecology of our streams and lakes. The resulting pollution requires considerable expensive treatment before that water is safe to drink.
Because I’ve been adding compost to my beds for twenty years, the soil is quite healthy and contains many nutrients. But vegetable production is nutrient-intensive, so I do add organic fertilizers to my veggie beds. For members of the Solanaceae family (tomatoes, peppers, eggplants, potatoes), I use a mix specially formulated for them. It seems to kick flower production into high gear, and since you can’t have tomatoes and peppers without flowers, I give these plants a boost.
For squashes, beans, and spring greens, I rely on a balanced organic fertilizer with a relatively low nutrient load. I’m looking for balance here, and just a bit of a boost to the soil already there.
Root crops — in my case, beets and carrots — seem to require a trace nutrient or two that my soil is low on. When I use an organic fertilizer specially formulated for these crops, I get much larger beets and carrots.
Follow instructions for these fertilizers. More is NOT better.
I do make my own, but it is never enough, not by a long shot. Resources abound with instructions for making compost. Your favorite search engine will tell you all you need to know.
Although I never make enough compost for my needs, a number of nearby suppliers offer excellent compost options. They will deliver partial truckloads, or if you have a pick-up truck (or a friend with one), they’ll load it for you. If you have neighbors, consider sharing a truckload.
The compost above is used by local organic mushroom growers. They mix a variety of organic components together for growing their mushrooms, but they discard it after one crop to prevent disease issues — much the way I rotate my crops annually, only they discard their growing medium. This year’s batch seems a bit more fibrous than last year’s, so I’ve decided to use it to mulch my veggies. It’s fibrous enough to suppress weeds, while it retains moisture and slowly allows nutrients to seep into the soil.
I’ll use these wood chips to mulch ornamental beds that aren’t close to my house (termites love wood chips), and to top off any paths in the veggie garden that have low spots. In my yard, wood chips usually last about three years before they break down into soil.
Soil for container-growing and seed-starting
I am of the opinion that potting soil offered in bags at home improvement stores and many garden centers is lousy. Now such merchants are pushing potting soil that already contains fertilizer to “save you time.” Please, I beg you, do not be fooled. First, these fertilizers are not organic, second, one size does not fit all when it comes to fertilizer, and third, while you may get initial rapid growth, the poor quality of the actual soil provided will eventually cause your plants to suffer.
If you are trying to grow veggies in containers on your patio, I recommend that you make your own soil by purchasing top-quality topsoil and compost from a local provider. Find such a person through recommendations from seasoned gardeners. All providers are not created equal.
If you are hard-core and have the time, you can create your own seed starting mix by baking good soil you created yourself in an oven to sterilize it. Personally, I don’t have the time, and I think it’s probably hard to ensure you kill all potential contaminators. I rely on a professional-grade soil mix that I’ve been buying for years from a local garden store. They are going out of business, alas. So next year, I’ll pay the extra cost of having it shipped in. It will totally be worth it.
The Metro-Mix soil blends are ideal for seed germination. I am certain they are the reason I achieve almost 100% germination from every flat I plant. These mixes contain no added nutrients. You don’t want fertilizers in the soil when you sow seeds. Seeds contain all the nutrients they need to germinate and initiate plant growth. After a week or two, I start adding a dilute mixture of fish emulsion/seaweed when I water them. This is all the seedlings need to flourish until it’s time to transplant them to the garden.
This blog entry grows long, so I’ll stop for now. I hope this helps all you garden newbies out there. I can’t emphasize enough the critical importance of excellent soil. If you’ve put in the time and resources to create good soil, almost any plant you grow will flourish, whether you grew it from seed yourself or bought a flat of seedlings from a local garden center. But if your soil isn’t healthy, your plants will not thrive.
So get out there, and get dirty, people! 🙂