Whenever you want to establish any type of garden or planting area, the first and most important issue is to determine if the soil/location will support whatever you want to plant in it. Several critical factors will affect your planting success—solar exposure, moisture levels, nutrient needs, and pH levels. Solar exposure is the easiest and most obvious to determine and take into account. In many instances, it will be something you can’t control, so you either need to select the type of plant you will grow based on the amount of direct sunlight your planting location receives or you will have to select a different planting location to satisfy the solar needs of the plant.
Moisture levels will depend on drainage, seasonal rainfall patterns, and water table levels. If you dig into your soil and the hole fills with water, you have a high-water table. That may be a seasonal (periodic) issue or a year-round issue, which you will have to know from experience or determine. If you want to put a planting bed in an area where sycamore, cedar, or willow trees grow, or you see wetland vegetation growing, you can expect the water table to be high most all of the time. Again, you will probably have to choose your plantings or garden location to fit the ambient water table levels. However, if your soil is occasionally dry, you may want to use commercial gel crystals when planting to help store the water you apply at planting so that the early roots will have access to the water they need to get started. If stormwater drainage is an issue, you may need to elevate your bed or dig an alternative drainage swale to protect your plants. At least you have some measure of control over that issue that you may lack with regard to the water table.
Nutrient needs can be addressed through some form of fertilizer supplement (which are available at many stores) or through rotational plantings—in the case of a vegetable garden. Usually, the packages of the seeds you purchase will give you general nutrient requirements for the plant. We have been rotating the crops we plant in our vegetable garden to allow the plants to regulate soil nutrient levels and minimize our fertilization costs. The roots of certain plants will increase nitrogen levels in the soil and others will diminish it. Learning how each plant impacts the soil will allow you to decide which plants to rotate from season to season to manage nutrient levels naturally. You can also use composted food waste to manage nutrient levels conveniently wherever you may decide (from your plant’s health) that enrichment is needed.
Perhaps the most difficult soil preparation issue you need to consider is pH levels. Not only is it more difficult to measure, it is also very critical to your planting success. Soil can be highly acidic (with a very low pH level ranging from 0-6) or very alkaline or basic (with a very high pH level ranging from 8-14). A pH level of 7 is considered neutral. Many people collect soil samples and send them to a commercial lab to analyze soil pH levels. Once the analysis is completed, you will receive a bewildering report of soil data that is often hard to interpret or to understand what you need to do to correct it. However, we have learned a time-honored, simple, convenient, and affordable way to analyze relative pH levels yourself using common household chemicals. We used this technique to determine how to amend our own vegetable garden soil to support the needs of the crops we plant. This is one of those times that our kitchen is called upon to serve as our Peeper Pond Farm laboratory. Please don’t report us to the Health Department for doing this; they’ll only have a conniption fit. If that doesn’t cause you fear, here’s how you do it.
First decide where you need to collect samples, depending on the size of your planting area. If you are planting a tree or bush, one sampling location may be all you need to test. If you are planting a garden, you may need to collect samples from several locations to ensure that each planting plot has the best relative pH level for the crop you intend to plant. For each location you wish to test, collect two samples of soil in separate cups (or divide one sample into two cups for testing). One of the samples will be used to test for acidic soil and the other will be used to test for alkaline soil.
The chemicals you will need to test soil pH levels are vinegar and baking soda, both of which are standard household cooking products. Vinegar is very acidic, so it will be used to determine if the soil is alkaline. Baking soda is very alkaline, so it will be used to determine if the soil is acidic. Many children have learned that mixing baking soda and vinegar will produce a strong reaction because they are on opposing ends of the pH scale. During my childhood, I used them as fuel for the simple bottle rockets I made.
However, before baking soda can be used to test your soil, it must be dissolved in water. Since water can be slightly acidic (depending on the source you use) you need to be sure that the water will not react with the baking soda you will use, or it will give you a false test result. Simply place a few tablespoons of baking soda in the water and watch for it to produce bubbles. If it does, the baking soda is reacting to acid in the water, which will contaminate your test. Whatever water you do use to test your soil for acidity must not react with baking soda.
When you have established that your water is not acidic, stir it well to dissolve the baking soda and pour the solution into one of your two soil sample cups. Make sure there is enough solution in the cup to make the soil thoroughly wet and stir it well to release any air that may be in the soil. Once it has been mixed, let it sit and watch for active bubbles to percolate through the wet soil and burst on the surface. Active bubbling in the sample indicates that the baking soda is reacting with acid in the soil, thereby indicating that the soil has a low pH level and is acidic. The relative ferocity of the reaction is an indication of how low the soil pH level is. A strong reaction means the soil is very acidic, where a light reaction means it is lightly acidic. This observation indicates relatively how much soil amendment you need to add to reduce the acidity to the levels you desire. If there is no reaction to the baking soda solution, your soil is either neutral or alkaline. You now need to test the second soil sample to determine which it is.
Take the second soil sample and add enough vinegar to it to thoroughly saturate the soil. As you did with the baking soda test, stir the sample well to completely saturate it, then let it sit. If the sample produces bubbles, it is evidence that the acidic vinegar is reacting to alkaline soil. Again, the relative ferocity of the reaction indicates whether the soil is highly or lightly alkaline. If there is little or no reaction to either the vinegar and baking soda, the soil is neutral with a pH of about 7.
Once you understand the relative pH level of your soil, you can amend it, which will adjust the pH level to satisfy your planting needs. Our own Peeper Pond Farm garden soil tested slightly acidic, so we applied wood and pellet stove ashes to the garden plots where we will plant vegetables that need more neutral soil—such as carrots, beans, and peas. This allowed us to make practical use of the ashes our cook stove and pellet stove produced during the winter. Otherwise, we would need to purchase some commercial lime to elevate the pH levels in those planting areas. You should be aware that soils tend to be more acidic east of the Rocky Mountains and less acidic to the west, but that is just a general observation.
If your test results show that your soil is too alkaline for your plants, then you will need to lower the relative pH level by applying an acidic amendment, such as coffee grounds (another typical household waste—especially in Seattle) or commercial sphagnum peat moss. Some commercial coffee shops will allow you to collect their used coffee grounds for this purpose. These are the most affordable amendments you can use to adjust the ambient soil pH levels of your planting sites.
These are the most simple and self-reliant techniques you can use to decide the best places to grow your plants or to adjust the conditions of your desired planting location to best suit your plant’s needs. Old-time gardeners and farmers know and use these practices, as they are all based in common knowledge and “horse sense.” We just wanted to share them with you as our way of preserving and promoting these traditional lifestyle skills.