Vegetable growers spend a lot of time thinking about conditions that affect the successful growth of plants, such as rainfall, sun, and temperature. But they often neglect the soil, which is where plants get the nutrients they need to grow. Soil pH determines the availability of these nutrients; Therefore, for plants to thrive, you need soil with an appropriate pH value for the plants you are growing.
Fortunately, you can change the pH value of your soil, naturally, for healthy plants and a productive garden.
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What are the soil pH values?
By nature, soil can be acidic or alkaline. You can determine what type of soil you have by measuring the pH value. There are several ways to test soil pH. For example, you can take a soil sample and send it to a lab for analysis, use a store-bought test kit, or create a soil pH test yourself.
It must be emphasized that the results obtained from a DIY test will not be as accurate as a laboratory test, but it will certainly give you some clues as to whether your soil is acidic or alkaline. Learn more about methods for testing soil pH.
Providing the correct pH value for your soil is the best thing you can do for your plants.
Most soils have a pH value somewhere between 3.5 and 10. In areas that get a lot of rain, soil pH values usually range from 5 to 7, while in drier areas, pH values usually range from 6.5 to 9.
Here is a quick reference for soil classification according to pH value:
- 7.6 and above: alkaline
- 6.5 to 7.5: neutral
- 6.5 and below: acidic
- Less than 5.5: very acidic
According to experts from the University of Nebraska – LincolnAnd Most vegetables do best at a lower acidity or acidity level The neutral range is 6.5 to 7.
However, some plants grow best in slightly acidic soil, in the range of 6.1 to 6.5. why is that? Such plants need higher levels of certain nutrients whose uptake is improved by having more acid in the soil. This group includes carrots, broccoli, celery, cucumbers, garlic, bell peppers, squash, squash, and tomatoes.
Furthermore, some plants do better at a pH closer to neutral. These plants include sweet peas, kale, lettuce, green beans, cabbage, Brussels sprouts, broccoli, asparagus, and radishes. On the other hand, potatoes do best in soils that are significantly more acidic, with a maximum of 6.0.
How to naturally change soil pH
One of the best ways to improve vegetable growing conditions is adding organic matter, or in this particular case, adjusting the pH value of the soil.
Natural amendments are usually added to improve soil structure, as well as to increase organic content and improve moisture retention. Keep in mind that the richer the soil in the amendments, the healthier the plant’s roots will be. In healthy soils with appropriate natural supplements, adjusting the pH level will not be necessary as plants develop a tolerance to acidic or alkaline conditions.
Raising the pH of alkaline soils
One of the most common ways to raise soil pH is adding limestone. Since adding limestone isn’t a quick fix, it’s best done in the fall, at the end of the growing season, well before seeding or transplanting seedlings.
Ideally, you could use a fertilizer spreader to evenly distribute the limestone. But if you don’t have one, you can use a shovel to spread the lime evenly over the surface of the soil. Once you’ve spread them, dig the soil to incorporate the lime as deeply as your plants’ root system. Then water well. The amount of limestone you use depends on your soil needs, but here are some rough numbers.
- Sandy soil needs about 2 pounds of limestone per 100 square feet.
- Clay soil needs about 3.5 pounds of limestone per 100 square feet.
- Clay soil needs about 5 pounds of limestone per 100 square feet.
Learn more about applying limestone.
2. Wood ash
Using wood ash is one of the easiest ways to change soil pH naturally but it is not long lasting. All you need to do is spread about half an inch of wood ash evenly over the surface of the soil to be treated, preferably on moist soil so that the wind does not blow it away. Then use a turner, shovel, or rake to work the soil. Avoid using chemically treated wood ash at all costs to avoid contaminating the soil.
3. Baking soda
Using baking soda is a cost-effective, quick, and easy way to increase the pH of your soil. All you have to do is mix a tablespoon of baking soda in a gallon of water and water your plants well. You will get the best results if you repeat the procedure every few months.
Lower the pH of acidic soils
1. Elemental sulfur
Did you know that soil bacteria convert sulfur into sulfuric acid, which lowers the soil’s pH? It is very important to stress that sulfur can increase plant resistance to disease.
For best results, apply sulfur before planting and then to a depth of 6 inches. This helps speed up the pH adjustment. However, if you are applying it to the soil where it is already planted, you will need to add elemental sulfur little by little whenever possible. Rake gently to mix it into the soil without disturbing the plantings.
For example, if you want to grow blueberries that need a pH of 5.5 but your soil has a pH of 7.4, feel free to use about 1 1/3 to 2 lbs. (2 3/4 to 4 cups) elemental sulfur per plant. To avoid burning the roots of the plant, this must be done before planting blueberries.
If the plant is already established, use 1/6 pound (1/3 cup) of elemental sulfur per plant. Repeat the process for the next month until your soil reaches the desired pH level.
2. Peat moss
Peat moss is an excellent soil amendment for acid-loving plants and can also help retain moisture in the soil. Note that the procedure is very slow and there is a possibility that it will not be effective in causing significant changes in soil pH. If you go this route, we recommend adding a 1-inch to 2-inch layer of peat moss and incorporating it into the top 6 to 12 inches of soil before planting. Unfortunately, harvesting algae destroys ecologically beneficial wetlands and releases carbon dioxide, a major contributor to climate change. Therefore, we recommend alternative solutions to lower soil pH.
To lower the soil pH with vinegar, you need to create a dilute vinegar solution. Mix 1 cup of vinegar per 1 gallon of water and water your plants using a watering can or inject it into your irrigation system. This is quite enough to get started, test the soil regularly and if no changes appear or the changes are very small, feel free to use one of the previously mentioned methods.
Gardening begins with the soil
It is well known that success in gardening begins with the soil. It is the foundation of your entire garden. Accordingly, an appropriate pH value is of great importance as it determines the availability of almost all essential phytonutrients.
You cannot have healthy and productive plants without good, well-balanced soil. This is where natural amendments, which have the ability to improve general soil condition as well as deliver nutrients directly to your plants, come to the rescue.
Finally, don’t be discouraged if everything doesn’t work out the first time. While it may take some time to determine which procedures will produce the best results, it is possible to make the most of the garden soil you have available.
This article was originally published on September 13, 2022.
About the author
Tony Manhart is the founder and editor-in-chief of Gardening Dream. Tony’s enthusiasm and rich experience in all things plant growing has led him to share his knowledge with gardening enthusiasts all over the world. When he’s not working in his garden, Tony spends his time writing tips and tricks on various topics related to plant cultivation and soil maintenance.