Spring is just around the corner and with it comes your last opportunity to make major improvements to your garden soil before planting vegetable plants and flower seeds. Actually, improving garden soil should be an ongoing process throughout the year. Everything you do in the garden should be with a mindfulness of how it will affect the health of your soil and, therefore, your plants. Everything you do will either add to the health of your soil or deplete it.
An example is the nitrogen level in your garden. If you plant corn in your garden, you will deplete the nitrogen because corn is a heavy consumer of nitrogen. If you plant peas or other legumes, you will add nitrogen because legumes can fix the nitrogen on their roots. So, when planning this year’s garden, you might want to plant the corn in the bed that had peas or beans last year, or peas and beans where the corn was last year. It is a matter of supply and demand. Your job as a gardener is to keep the balance.
Start the process of improving the soil about four weeks before you will start planting. Evaluate the soil as it currently is. Clay soil is hard, won’t absorb water or nutrients easily and will be difficult to grow root crops. Sandy soil drains water and nutrients quickly and will easily dry out. Both soil conditions can be corrected by amending the soil. Your goal is rich, healthy soil with a good balance of nutrients available for your growing plants and lots of earthworms.
Many gardeners today are embracing the “no-till” method of gardening.
While this has many benefits, this is one time you may want to bring out the rototiller or be prepared to manually dig deeply into the soil. In both cases, the solution is to add lots of organic material and ideally mix it in to achieve a depth of about 18 inches. The organic material will absorb water and nutrients and hold them in the sandy soil for the plant roots to access. In clay soil, the organic material will break up the clay and give the roots the ability to penetrate the soil and access nutrients.
This is a quick way to address a more extreme soil condition. An alternative is to convert your garden to raised beds and fill the boxes with healthy, clean soil. This comes with the expanse of materials to build the boxes and purchasing soil to fill them. The biggest problem is finding good soil that has not been contaminated with herbicides like Roundup. Herbicides can remain effective in the soil for years, and it will not discriminate between weeds and seedlings.
If your soil is in good condition, there are still steps to take each year to keep your garden healthy and productive.
1. Clean up
Remove any leftover plant material from last year’s garden. If any weeds have survived the winter, remove them while they are small. Remove any branches, rocks that have surfaced or dead leaves.
2. Purchase a soil test
A soil test will measure the levels of nitrogen, phosphorus and potassium (potash) in the soil. Nitrogen is essential for leaf growth and green color. Phosphorus helps with plant growth, seed and fruit production and disease resistance.
Potassium contributes to great root production. Soil test kits are available for use by the home gardener and will tell you in minutes if you need to amend your soil with any of these nutrients.
3. Start composting
Hopefully, you have a compost bin or are making your own compost. It is a great way to return organic material to the soil in a usable form–and it’s free. A bin or barrel composter will keep everything neat and tidy, but you can make compost by just piling up the material.
Just alternate layers of dry material like fall leaves, shredded paper or straw with green material like fresh grass clippings, carrot greens and potato peels.
Keep the pile slightly moist and turn it to let air in. In a few short weeks, you will have compost. If you have a supply of compost, spread a layer over the entire garden before you plant. If the amount of compost is limited, side dress the seedlings with compost.
4. Consider using manure
Manure is used to add nutrients and organic matter to the soil. In addition, manure contains microbes that contribute to soil health. If you are adding manure to your garden in spring, you need to be very sure that the manure is well composted. Manure should sit for at least a year before it is added to the garden.
Some gardeners add the manure in the fall to be sure it is safe. One exception to this rule is rabbit manure. Rabbit manure is considered “cold” manure and is safe to use fresh as it will not burn the plants.
5. Cover Crops
Cover crops are typically planted in the fall and added to the soil in the spring, but they can be planted in the spring if you have the garden space to spare. There are a number of different crops to use for cover, including clover, radish and buckwheat. The choice is based on the type of soil you have and the grow zone your garden is in.
When the cover crop has grown, mow it with a mulching mower. After it is mowed, mix it into the soil. The smaller pieces will compost in the soil faster. Additional benefits of cover crops are for weed suppression in the summer and soil erosion in the winter.
6. Lay down mulch
The primary purpose of mulch is to hold the moisture in the soil and prevent it from evaporating in the sun. It also is important for weed suppression. Finally, as it breaks down, it provides more organic matter for the soil.
7. Use amendments
Based on your soil test results, there are amendments you will add to bring the levels of each nutrient to optimal levels. These include things like fish emulsions, bone meal and calcium.
If you have healthy soil, your plants will be healthy also. Healthy plants are more disease- and pest-resistant and produce the bounty we all strive for in our gardens.