Adding garden lime to acidic soil is the most common way to raise pH levels and help sweeten it. However, some limestone treatments are too harsh for some plants and may cause further complications in the soil later on—not to mention the questionable sustainability of the limestone mining industry. For these reasons, you might wish to avoid using lime to sweeten your soil, yet what else can you do?
Here are six tips for how to sweeten soil without lime:
- Test soil before applying treatment and regularly afterward.
- Consider the crops or plants that will grow in the soil.
- Use wood ashes as a lime substitute.
- Apply a baking soda solution to make the soil more alkaline.
- Add animal manure to the soil to lower acidity.
- Avoid using acidic fertilizers or peat moss.
If you’ve been searching for a lime alternative for your soil, this post is for you. Keep reading to learn more about how to sweeten soil without lime.
1. Test Soil Before Applying Treatment and Regularly Afterward
Before you do anything to alter your soil, you must determine its current pH balance. A soil’s pH level—more specifically, the level of aluminum—is the reason for whether the soil is sweet, sour, or neutral.
Notably, aluminum benefits some plants and organisms living in the soil, yet it is toxic to others.
When someone describes soil as sour, they mean it is acidic, with a pH below 7 (the neutral range). Likewise, sweet soil is alkaline, with a pH above 7.
How To Test pH Levels
If your soil is sour and needs sweetening, it may be possible for you to determine this simply by a smell test. Often, highly acidic soil can have a foul-smelling odor to it.
Otherwise, you can choose from a variety of different pH test kits available for purchase online or at gardening supply stores. We recommend the Saysummer Soil pH Test Strips (available on Amazon.com).
Just mix equal parts soil and water in a glass, and soak the strip for 30 minutes. The premium filter paper strips won’t bleed, and the results are clearly displayed on the pads and easily interpreted with the color chart on the packaging.
Alternatively, you can conduct a DIY pH test at home using vinegar and baking soda. For this method:
- Obtain two soil samples from the same place in your garden or lawn.
- Stir each sample into its own glass of distilled water, adding a tablespoon of vinegar to one sample and a tablespoon of baking soda to the other.
- Look out for bubbling or fizzing. Vinegar is acidic, with most ranging between 2 and 5 pH while baking soda is alkaline, typically with a pH of 8 or slightly higher. So, if the glass you add vinegar to begins to bubble and fizz, the soil is alkaline. If the glass with baking soda bubbles and fizzes, your soil is acidic.
2. Consider the Crops or Plants That Will Grow in the Soil
While every plant is unique and has unique pH preferences, most grow optimally in neutral soil. Generally, an ideal soil pH ranges around the neutral zone, between a somewhat acidic 6 and a mildly alkaline 7.5.
Once the pH levels move outside this optimal range and are too sour (acidic) or too sweet (alkaline), some plants may struggle to take in the nutrients needed for proper growth. In such cases, plants will fail to grow correctly or even die. Still, others may thrive. Notably, most lawn grasses grow best in alkaline soils.
Additionally, some plants might alter their appearance. For example, many gardeners purposefully increase acidity in the soil so that pink hydrangeas will appear blue instead.
All the same, some plants prefer more acidic soil with a pH of 6 or lower for optimal growth and health.
Some examples include:
Thus, it’s essential to consider the plants, flowers, trees, or crops you have or will grow in the soil to determine the best action for sweetening the soil. Some options may not provide the other essential nutrients your plants require. Moreover, this may result in adverse or otherwise unwanted consequences.
3. Use Wood Ashes as a Lime Substitute
Wood ash is the next best thing to lime as an organic way of reducing soil acidity. As the preferred lime substitute for many farmers and home gardeners, wood ash contains as much as 70% calcium carbonate, which is enough to help raise pH levels in acidic soil.
It also has potassium, which helps to stimulate flowering and strengthen plant stems, and provides soils and plants with magnesium, phosphorus, and other trace nutrients such as copper and zinc.
The only notable drawback is how long it can take before you see significant results. While you should apply most limestone products to the soil about three months before planting, wood ash typically requires a year or more to do its job before the soil reaches the desired pH level.
Thus, you should only choose this option if you have the time and patience. Notwithstanding, you may achieve sweet soil when you apply wood ash properly over time.
When using wood ashes in your garden, it’s essential to be mindful of the source. Some woods have certain chemicals that remain in the ashes after the wood is burned, which may harm your lawn or garden.
Caution: Wood ash should be used sparingly in the application. Impose a limit of 1 pound per 50 square feet (16 ounces per 4.65 square meters) and apply it once every two years. Also, consider wearing eye protection and a mask when handling and applying wood ash, especially on a breezy day, to prevent it from blowing into your eyes or mouth.
4. Apply a Baking Soda Solution To Make Soil More Alkaline
Not only can you use baking soda to test for acidic soil, but you can also use it to sweeten the soil.
To do this, follow these simple steps:
- Add one tablespoon to a gallon of water and stir to dissolve.
- Apply the solution to the affected soil
- Test the soil regularly starting the next day to monitor the pH levels.
5. Add Animal Manure to Soil To Lower Acidity
This option is an easy and effective way to sweeten your soil if you have access to animal manure. Researchers have concluded that the manure from some farm animals can significantly increase pH and reduce acidity. For this study, they used the dung of five different animals, as follows:
To learn more, you could check out my other article on whether horse manure raises or lowers soil pH: Does Horse Manure Raise or Lower pH?
6. Avoid Adding Acidic Fertilizers or Peat Moss
Peat moss has a somewhat acidic pH and is best used to increase acidity in your soil. It’s an effective organic substance for correcting a high alkaline level, which is why many fertilizers contain peat moss as a primary active ingredient.
Due to this, you should avoid using peat moss or other acid-based fertilizers when trying to sweeten your soil. Regardless of your chosen method, adding such acidic substances will also affect pH—but in the opposite direction. Ultimately, this will leave you waiting much longer than needed for the soil to reach a neutral pH level.
If you’re growing acid-loving plants or crops, group them in an area separate from the soil you’re trying to sweeten. This separation will help to ensure any fertilizers they require won’t hinder the landscape you’re treating.
While adding some form of lime is considered the most effective way to sweeten acidic soil, wood ashes make for a great alternative. Just be sure to keep the following in mind before using any amendments:
- Test the pH level of your soil before and after treatment.
- Consider the plants you intend to grow and their nutritional needs.
- Avoid acidic fertilizers or peat moss when trying to maintain sweet soil.
If you still feel unsure how to sweeten your particular soil, contact experts to discuss the pH levels. They can help you to determine the ideal solution for your lawn.