In my previous two articles, I explained that I break garden soil fertility management into three stages. We stepped back and looked at the important roles air and water play in these three stages, too.
Now we’re going to look at the final two stages of garden soil fertility management:
- Forming and finishing garden beds
- Seasonally recreating gardens for succession planting
Stage Two: Forming Permabeds
Stage two of garden soil fertility management occurs in sync with the second phase of garden transition—namely, forming Permabeds from scratch.
In this phase, the garden plot is organized into raised garden beds that have a specific width and height for your scale of operation. Up until now the plot has been in cover cropped land with an application of composted manure (stage one).
Mow the Cover Crop
Now is the time to flail mow the cover crop. You can use a BCS tractor with a flail mower or larger tractor with a flail mower, depending on your scale. The flail mower will chop the cover crop into small pieces that are easily integrated into the soil to decompose.
This will add organic matter to your garden soil.
Forming the Beds
Now, you can form your beds with a bed former and power harrow. The beds will be raised up roughly at first, but before you do a second pass with a power harrow, you can apply more compost to the bed top.
A typical compost mix will work fine, and you can source what is available in your area. Mine is made from a mix of composted manure, rotten hay and straw bales, and some decomposed hardwood tree mulch, all mixed with a local sand to lighten it up. (Most of our local soils are clay based.)
Apply this compost to the bed top, 1 to 3 inches thick depending on budget and how much you want to loosen and improve your soil. Then power harrow this into the top 3 inches of the soil.
Essentially, you are enriching the top of the garden bed to form a new garden top soil. In science terms, this is your “A horizon.” The A horizon of most soil is higher in organic matter, with a darker, richer and more crumbly soil color and texture.
This makes soil more stable against erosion and compaction. It also provides overall better soil-to-seed contact in those top inches for best germination of fine seeds like carrots, arugula and lettuce.
Stage two is about building your garden beds and making a soil that is layered like a natural ecosystem. But you’ll also gain garden quality nutrient availability for years of better crop growth.
The final stage of garden soil fertility management mirrors the third phase of garden formation—namely, the period of continuous garden fertility management through the annual crop cycle. In this period there are three main fertility management techniques I apply.
1. Reapply Compost
First, I reapply the compost from stage two onto the bed tops. I do this every one to three years for the first decade of gardening. In stage three, though, I only apply 1 inch of compost.
Here’s my schedule for applying compost during that decade:
- I apply it each year for three years,
- once again at the six-year mark
- and again at the nine-year mark.
At the end of this decade, you’re left with a Permabed of upmost quality. And it’s not hard—the compost spreader from my two-wheel tractor does a great job at this.
You can also apply compost by hand with shovels and a wheel barrow, or by shoveling out of a compact tractor’s bucket.
2. Plant Cover Crops
Secondly, I use cover crops to help fix, store and cycle nutrients back into the soil. Cover crops are used in rotation with the vegetables. And I select certain cover crops to help fix certain nutrients:
- Clovers fix nitrogen
- Buckwheat sequesters phosphorous
- Winter rye builds copious organic matter
Each cover crop has its own season as well. Winter rye will overwinter and hold soil against erosion. Buckwheat germinates and grows best in summer. And clovers need a good 18 inches to establish properly.
I grow cover crops in the beds after flail mowing the vegetables. I also grow some cover crops, like white clovers and annual rye grass, in the paths—for instance, between beds of kale and cabbage.
3. Side-dress Heavy-feeder Crops
Thirdly, I side-dress (apply nutrients close to the roots of) heavy-feeder crops, like melons, tomatoes, peppers and broccoli. For this, I use micro-nutrient blends and soluble plant fertilizers.
For years, I have favored blends made by Neptune’s Harvest. Their nutrients are readily available, and different blends can achieve different results, for instance:
- encourage root development in spring and fall for perennials
- enhance green-leafy growth for greens and tomatoes in spring
- enhance flowering and fruiting in summer
I apply these with a backpack sprayer calibrated to the right ratio, and I walk and spray the soil along a line of the crop row. You can also do foliar sprays, but I like to feed the soil, as this encourages healthy soil life, too.
Side-dressing could also include granular fertilizers like blood and bone meal, kelp meal and rock minerals. You could also set up some seeders to side-dress granular nutrients. Many older Farmall tractors allow you to side-mount a fertilizer attachment.
Side-dressing gives heavy-feeding crops an extra boost to improve seasonal yield. Ultimately, side-dressing will be of greater benefit in the early years, when the soil is still finding and balance.
After a decade of following these practices in stages one, two and three, your Permabed will be in great shape.