Should You Add Lime to Your Soil?
How To Improve Plant Health Through Soil Amendments
All dirt is not created equal.
Some soil needs a little help. Amendments are a great way to boost your soil’s health, which can in turn lead to healthier plants.
Unlike fertilizers, which add nutrients into the soil, amendments actually modify and improve the overall soil quality. From allowing easier root penetration to improving water-holding capacity, amendments can make growing a healthy garden much easier.
While the exact amendment required depends on the specific problem your soil faces, a common issue faced by many gardeners surrounds soil acidity.
This is where lime comes into play.
What is Lime?
No, we’re not asking about the green citrus fruit–we’re explaining the soil amendment made from ground limestone–a naturally occurring rock that is high in calcium. Along with supplying soil with calcium, it’s main purpose is to raise pH (making soil less acidic).
Why Does Soil pH Matter?
Soil pH, which is a measurement of the acidity or alkalinity of soil, is crucial because it determines how easily plants can absorb nutrients from the ground. When soil is too acidic (generally below 6.0 pH), crucial macronutrients such as phosphorus, potassium, and nitrogen cannot properly dissolve.
Once you know the pH of your soil, you can make the necessary adjustments. If you find that your soil is more acidic than you’d like (especially with a pH below 6.0), lime might be just the thing you need.While most plants can live in soil with pH between 6.0 and 7.5, the best thing you can do to ensure your garden has the optimum pH for your plants is to test your soil! It’s the only sure-fire way to check if your soil is healthy.
How Does Lime Reduce Soil Acidity?
Lime can remedy high acidity levels by catalyzing a chemical reaction within soil, subsequently raising the pH (high pH = less acidic). Because the majority of plant nutrients in soil become readily available for plant uptake at a neutral (7.0) or near-neutral pH, a boost in pH may increase the uptake of nutrients. The benefits of applying lime do not stop there, however. The high calcium content in lime can also support healthy plant growth and development.
When You Should Lime Your Soil:
The optimal time to add lime your soil is during the fall, allowing for several months of lime dissolution before spring plantings. Lime must fully dissolve to have maximum impact. While you will begin to see a measurable difference in soil pH around a month after adding lime, it can take up to 12 months for lime to completely dissolve into soil.
How to Apply Lime to Soil:
Before adding lime to your soil, you must first prepare the area by digging to a depth of 8 to 12 inches. Spread the lime evenly over the soil, then rake it into the ground.
The amount of lime your soil requires two key pieces of information:
How do you find these things out? You guessed it–you test for it!
Estimating the correct amount of lime (or any amendment) without a test is just a guess. While soil amendments are intended to improve your soil quality, unnecessary applications can cause more problems than they solve. In fact, too much lime can cause the same problem as acidic soil: the inability of plants to take up nutrients. Regularly testing your soil is the only guaranteed way to make informed decisions and get the results you want.
If you have any questions regarding soil health, take a look at our growing blog series–The Dirt on Soil. If you’re unable to find what you’re looking for, just send us a message at firstname.lastname@example.org and we’d be happy to help!