Hold off on no-dig and lasagna gardening
With paper and cardboard shortages already happening and predicted to worsen, now is not the time to take them out of the recycle chain to put into gardens.
Cardboard is needed at almost every point in the supply chains of everything we buy from stores. Without packaging and shipping cartons, production and supply slow down. Shortages also raise prices and the price increases are always passed on consumers and small businesses, many whom are already struggling to make ends meet.
Without layers of cardboard, we’re back to the double digging method of establishing new in-ground beds for ornamentals and edibles.
Double digging is extreme tilling, done only when the soil requires heavy addition of organic matter. If your soil lacks organic matter or nutrients, is too compacted or has too much clay or sand, this one-time amendment process is necessary to produce healthy plants.
Although double digging goes against the recent science supporting no-till gardening, the exception is when we are starting with soil that isn’t adequate for healthy plant growth. A suburban yard is not farmland. Plus, a suburban gardener often tries to squeeze a lot of production out of a small area. Flowers, fruits and vegetables are heavy feeders that only do well if their roots can grow freely and gather plenty of nutrients.
Normally, tilling is not advised because it can destroy the soil structure needed for good habitat for the microorganism’s living in the soil. However, if your soil lacks organic matter, the structure is already unfavorable and there won’t be many organisms to disturb. Amending the soil will eventually enable plants to grow well, adding more oxygen to the environment and removing carbon.
Tilling is also criticized for aerating the soil, increasing biological activity, resulting in rapid decomposition of soil organic matter. In already healthy soils, tilling might result in loss of organic matter. However, the point of double digging is to add organic matter. You also want the aeration to increase microorganism activity and reproduction.
Double digging in the fall gives the soil several months to recover before spring planting. When a large amount of organic material is added to the soil, microorganisms multiply rapidly. Since they construct their bodies from the same nutrients that plants use, soil nutrients can be relatively unavailable until the organic material is broken down and nutrients are released. The sooner you start, the more time your soil will have to regain its health.
- Start in late summer, by deciding what you want to grow and see if there is a spot that these plants might thrive in. Plants need what they need, it is futile trying to cheat them. Flowers, fruits and vegetables mostly need at least part sun. There are many wonderful ornamental plants for shade, but few edibles. Tree roots are a common issue and it is not advisable to try to combat them. They will take over your new bed and outcompete whatever you try to grow there (there are some exceptions). If you will be happy with a little or short-lived success, then go for it.
- Next, test the soil in that area. DIY kits from hardware stores are not very thorough. The most common way to get a good soil test done is to contact the Cooperative Extension of your state college. For New Jersey, it is the Rutgers University Cooperative Extension. https://njaes.rutgers.edu/soil-testing-lab/. This may take several weeks, so aim to do it a month before you dig.
With COVID-19 issues, getting a soil test kit had been challenging, so perseverance is required. Fall is a much slower time for the soil testing lab than spring, so you might get it done more easily then. - Get the amendments that your test results recommend. I find that the local Agway store very helpful for both supplies and advice. The essential tools are good gloves and a sturdy garden spade and fork. If you have a lot of rocks or tree roots to deal with, research specialty spades that make the work easier. A wheelbarrow is very helpful, but not essential. This is going to be a workout, so get a comfy chair and beverage ready for lots of breaks.
Very often, the recommendation is to add organic material. If you have a big pile of compost, leaves (another reason fall is a good time to amend) or untreated sawdust, go ahead and use those. Gardeners with the space and means might order a truck load of compost. If that’s not possible for you, consider buying bales of peat moss or coir. Coir costs more and is a renewable resource, unlike the harvesting of peat. These are easier to manage if you plan to complete the dig over several days or weekends. However, they do not contain the nutrients that compost provides, so nutrients will need to be added.
How much organic matter do you need? It depends on how heavy or hard your present soil is. If it’s solid clay, you will need to mix in at least 50% organic material. This gets tricky, because you will have twice as much material as what was in the ground. Mounding it up is fine only if it’s not going to run off. If it is, you will need to find somewhere to put half of the clay that you dig up.
Since people take in information differently, I find that it helps to view more than one approach to the same task. Here are a few links to excellent tutorials on double digging by Green Thumb Gardening Secrets (credit main photo), Milkwood and Fine Gardening.
To be safe, consider checking if there are buried pipes or wires where you plan to dig. What you hit may not be a rock. In New Jersey, there is a Call Before You Dig service.