Gypsum is a good way to raise ph. Typically low ph is correlated with low calcium, though not always. If so, calcium heavy gypsum is a good way to raise ph. Potash and wood ash are also good ways to raise ph.
Sulfur is the best way to lower soil pH. Peat moss added to soil also helps, but that only works when it is mixed in the soil before planting.
Another popular amendment is wood ash. If you have an outdoor fire pit, this may be a more cost-effective amendment for you. Just regularly take the ashes from the fire pit and spread them on your garden soil. As with lime, you'll need to test frequently to make sure the proper adjustments have been made.
Signs You Need to Apply Lime
You have sandy or clay soil. Both of these are naturally acidic. Weeds or moss have grown in your yard. The fertilizer you're using doesn't appear to be working.
There is no substitute for lime. The calcium or magnesium in agricultural lime are not what is responsible for its liming action.
To increase the pH of soil, a component that contains calcium and/or magnesium is used. The most common practice is to add a material that contains lime, however other methods such as using baking soda or eggshells will also increase the pH in soil.
Contrary to popular belief, it's a myth that coffee grounds are acidic and will lower the pH of the soil. After brewing, the grounds are close to pH neutral, between 6.5 and 6.8. Research shows that whatever change coffee grounds bring to the soil is short-lived, Brewer said.
Soil pH can be reduced most effectively by adding elemental sulfur, aluminum sulfate or sulfuric acid. The choice of which material to use depends on how fast you hope the pH will change and the type/size of plant experiencing the deficiency.
Some people say Epsom salt will make soil more acidic because of its sulfur content, but field tests usually show it has miniscule to no effect on pH.
Sphagnum peat moss is often suggested as a soil amendment to decrease soil pH. However, most peat moss found in garden centers is neutral or slightly acidic. Only Canadian sphagnum peat moss has a low pH of 3.0 to 4.5 and will effectively reduce soil pH.
If the soil is too acidic then farmers treat it with quick lime or slaked lime to neutralise the effect and make the soil neutral so that plants can grow properly.
🍋🥤 Here's the lowdown: it can lower soil pH and add nutrients, but overdo it, and you might damage the roots. A good mix is 1 tsp lemon juice in 1 liter of water. Store it in the fridge and apply only every 2 weeks.
Too much lime will raise the pH of your soil so much that many plants won't grow well and will start to show signs of nutrient deficiencies. Too much lime will also lead to high levels of calcium in your soil, which will prevent plants from absorbing magnesium (an essential part of chlorophyll).
Baking soda also does not last as long as lime (similar to the ashes) but can produce results in just a few days. Baking soda is fairly gentle on both the soil and the plants, so you won't have to worry about harming your plants. Mix a tablespoon of baking soda into a gallon of water.
Watering with vinegar is not a recommended method for lowering soil pH for a couple of reasons. First, you would need a large amount of vinegar to move the pH of a large garden bed from 7.5 to 7.0 and because you would not want to apply vinegar to the soil without diluting with water, this could take a while.
Increase Blooms with Baking Soda
Why Effective: By adjusting soil pH, it may help alkaline-loving plants absorb nutrients more effectively, leading to more vibrant blooms. Downside: Many plants prefer slightly acidic soil.
For most acid soils, the most practical management option is to add lime to maintain the current soil pH status or increase surface soil pH. For a better chance at successfully growing acid-sensitive species, consider liming once the pH drops below pHCa 5.0.
Check your plants for these signs to see if your soil is too acidic: Yellowing, browning, and dying leaves.