How does the soil become acidic or basic

Lower pH: 7 home remedies for acidic soil | Make the soil acidic

Plants depend on the right soil for healthy growth. But not every soil is naturally optimal, and the demands of the plants can also differ significantly from one another. The pH value has an important function here. Many plants thrive only or best in soils with an acidic pH. But what if this value is too high?


Need to acidify the soil

The pH value of the soil provides information on whether the soil reaction is acidic, neutral or basic (calcareous). An unfavorable or incorrect value can lead to poor growth and deficiency symptoms in the plants. It is all the more important, depending on the type of planting, to lower a value that is too high.

  • Many plants prefer slightly acidic to neutral soil
  • The pH of such soils is between six and seven
  • Some plants need a more acidic soil
  • The value of acidic soils is between 4 and 5.5
  • They hardly contain lime and a lot of humus
  • So-called bog plants in particular thrive here
  • Including rhododendron, camellia, azalea, laurel rose, heather and rosemary heather
  • Or crops such as blueberries, lingonberries or cranberries and kiwi
  • They can only absorb nutrients in appropriately acidic soils

In most gardens in Germany, the soils are normal or only slightly acidic. Naturally acidic soils are found almost only in untouched nature reserves. In the garden you usually have to help to make the soil acidic. Before you can take appropriate measures, it is advisable to determine the actual pH value by means of a soil sample.

Soil analysis creates certainty

A soil analysis provides information about the pH value, the type of soil and the nutrient content of the tested soil. It should generally take place every three to five years.

  • The best time to pick in late autumn or early spring
  • The easiest and most uncomplicated test is to use special test strips
  • Available in hardware stores, garden centers and pharmacies
  • Appropriate test strips, a small mason jar and distilled water are required
  • Tap water is rather unsuitable for this
  • Calcareous water would significantly influence the measurement result
  • For the test, add 100 g of a soil sample and 100 ml of distilled water to the glass
  • Close the jar and shake vigorously
  • Then let it stand for about ten minutes
  • Now dip the test strip into the liquid

The pH value can be read from the discoloration of the test strip. In addition to these test strips, there are other ways to test the pH value of the soil, but these are a bit more complex and tedious. If the test shows a pH value that is too high, you can lower it with various home remedies and make the soil acidic.

Home remedies to lower the pH

There are numerous ways to make the garden soil acidic. For the sake of the environment, however, you should avoid peat and chemicals. Sensitive peat bogs and thus important habitats can be protected in this way. It is best to use suitable home remedies, some of which can be found in the household but also in nature.

Patience is required for a sustainable and natural lowering of the pH value. This process is relatively difficult and can only be done slowly and over a long period of time. As a support, you should avoid calcareous fertilizers and calcareous irrigation water. Organic components have an acidic effect when they are worked into the soil and they decompose there. Home remedies that can be used to acidify the soil are coffee grounds, grape residues, coniferous soil, various compost mixtures or mulch.

Waste products from winemaking

If you live near a winemaker, you can use grape residues to acidify the soil. These waste products are created when wine is pressed. The fermentation substances and pure grape acids contained therein are responsible for lowering the pH value. Unfortunately, these waste products can only be obtained through a winemaker. Similar to coffee grounds, they also have a fertilizing effect. Therefore, you should not apply them in any large quantities to avoid over-fertilization.

Certain plants

Some plants can also influence the soil quality or lower the pH value of the soil. They have a certain tolerance towards alkaline or basic soils and usually prefer them. These include some evergreen shrubs such as boxwood or Californian lilac, deciduous plants such as forsythia, lilac and prairie squash, and some perennial shrubs such as hellebore (Helleborus).

However, these plants can only develop their effect if, after they have died, the dead plant material remains on the ground and it is returned to it in this way. What follows is a very slow lowering of the pH.

Tip:This method is probably the most tedious way to acidify the soil. If organic substances are involved, patience is generally required.

Coffee grounds

A home remedy found in almost every household can increase the acidic properties of a soil and thus lower the pH value in a completely natural way.

  • Coffee grounds can be used pure
  • Or as a mixture with shredded softwood or leaves
  • Coffee grounds contain many important nutrients
  • It is a valuable fertilizer, especially for bog plants
  • The set mainly contains potassium, phosphorus and nitrogen in significant quantities
  • Work the dried substance into the surface of the soil
Tip: Coffee grounds should definitely be dried before spreading, because damp grounds tend to go moldy.


Mulch not only protects against unloved weed growth and the soil from drying out, it also has an impact on the nature of the soil, as it can lower the pH value. This can be a two to three centimeter thick layer of the chopped wood of various conifers including needles or oak leaves as well as bark mulch, sawdust or lawn clippings. Lawn clippings should be slightly withered before application. The mulch layer has to be renewed after about two years.

Coniferous earth

If you need acidic soil, then coniferous soil is the right choice. The earth directly under conifers is called coniferous earth. It can be removed and placed in the soil at the desired location, where it then gradually makes it acidic. The removed soil can be refilled with normal garden soil. This method is particularly suitable for long-term results, because the decomposition process of organic materials takes a lot of time. For larger areas, the introduction of acidic humus from chopped conifers is more recommended.

Tip: Coniferous soil should always come from conifers in your own garden. Extraction from forests is prohibited.

Pure oak leaf compost

If you have a large oak in your garden, you have another useful helper to make the soil acidic. Pure oak leaves are a good alternative to special compost. It is very acidic by nature, which increases during the decomposition process. However, the composting process takes about two years. The finished compost is then worked flat into the soil.

Tip:Oak leaves on busy roads should not be used. It usually has a high level of pollutants.

Special compost

Another inexpensive and environmentally friendly way to make the garden soil acidic with home remedies is to prepare a special compost mixture. For this you need different organic components, which together have a strong acidic effect. You mix the bark, needles and sawdust of coniferous wood with the leaves of chestnut, walnut and oak as well as horn shavings and coffee powder. This special compost is also a very good fertilizer.

The pH value of the garden soil can determine whether plants will thrive or spoil. It should be neither too high nor too low and it should suit the needs of the respective plants. This is the only way to achieve healthy growth. Otherwise, it can be improved accordingly with various home remedies, which, however, can take some time.