It’s planting season in hardiness zones 6 and lower. But before you plant your small kitchen garden, it’s important to prepare the soil. Approaches to soil-preparation vary considerably, but they all have a few things in common:
Benefits of loosening soil include:
- Improved air circulation to roots of plants.
- Faster penetration of water into soil… and better drainage
- Better environment for earthworms that improve soil quality by breaking down organic solids.
- Eased raking, hoeing, planting, and weeding
- Improved penetration of soil additives applied on the surface during the growing season.
Reasons to add humus include:
- Mixed into soil, humus helps keep the soil loose.
- Humus retains water, releasing it gradually for plant roots.
- Humus provides nutrition for plants; it reduces or eliminates the need for chemical fertilizers.
- Humus feeds—and may even provide—microbes that are beneficial to your plants
Controlling your soil’s acid content can improve the production of vegetable plants. Unfortunately, some vegetables prefer acid soil, while others prefer neutral or even alkaline soil. For simplicity’s sake, I encourage you to work toward neutral PH in a vegetable bed; most crops will do fine, and you can make adjustments locally when you plant something that prefers higher or lower PH.
A slightly raised 16-foot-square bed needs the same treatment as a traditional in-ground planting bed: Add humus, turn the soil, rake it, mark planting areas, and cut trenches or dig holes.
To learn about manipulating your small kitchen garden’s PH level, find a Cooperative Extension office in your county, obtain a soil test kit from them, and submit the required soil sample(s) and paperwork. The analysis they provide for a fee should include guidelines for adjusting the PH; if it doesn’t, ask someone in the Extension office to provide you with guidance.
Absolutely get the soil tested if you’ve just created a planting bed, or if you’re about to plant in an existing bed where you’ve never planted. After making amendments according to the results of your soil analysis, you really shouldn’t need to test the soil again—people grew vegetables for thousands of years without getting the soil tested.
However, if you have problems growing some types of vegetables—especially if the problems recur from year-to-year, a new soil test is in order; you may discover the PH needs further tweaking to assure healthy crops.
Traditional In-Ground Planting Beds
Months ago, I defined a traditional in-ground planting bed as one that is simply a soil patch in which you garden. The patch is large enough that you need to walk in it to till, plant, weed, and harvest. Here are the steps to prepare a traditional planting bed as we prepared the family vegetable garden on my parent’s farm when I was a kid:
1. Remove any large items that you might not have removed in the fall—rocks, tomato stakes, plant cages, trellises, tools…
2. Cover the entire garden bed with six inches of raw horse manure. Alternatively, use raw cow manure. Ideally, use mushroom soil or mature compost.
If you’re hand-raking your garden, I hope it’s no larger than about 14 square feet. Alternatively, use a low-till approach as I’ll explain in my next post.
3. Plow and disc the garden bed. Our kitchen garden was large enough that plowing made sense, and the neighbor farmer generously stopped by each spring with his tractor to do the job. Your small kitchen garden probably won’t accommodate a tractor, so you might resort to a power tiller—or even a shovel—and finish by raking. In either case, you may need to use a thinner layer of organic dressing than I suggested in step 2; one goal of tilling is to work the horse manure into the soil, and it’s hard to work six inches of manure into the soil by hand. Many gardeners recommend three inches of organic matter, and that’s a good amount if you aren’t using machinery.
4. Pick weeds and rocks out of the loose soil.
5. Mark the rows where you intend to plant.
6. If your garden bed tends to collect rain water, mound soil from between the rows onto the rows, creating six-to-nine-inch berms. By mounding the soil you turn each row into a raised bed that will reduce the chance of excess moisture damaging your crops.
If your garden is on high ground that drains quickly, don’t mound the soil; step 7 will result in depressed planting rows that catch and hold rain water; an advantage especially in a dry year.
7. For seeds, hoe the rows into trenches to receive the seeds. For seedlings, dig slightly-larger-than-root-ball-sized holes in which to set the plants. The dimensions of trenches and holes vary depending on the types of vegetables you’re planting and—for seedlings—on the condition they’re in. Consequently, step seven is where planting instructions begin in upcoming posts.
Upcoming posts will discuss other ways to add humus to your soil. We’ll also talk a bit more about adjusting PH for specific types of plants.