Make the soil more acidic: lower the pH value without peat

An acidic soil is important for many plants in order to enable species-appropriate site conditions that improve growth and maintain the health of the crop. Many of the soils in Germany are normal or slightly acidic, but only a few soils are really acidic, most of which are in unused nature reserves. Therefore, the gardener has to help out by himself and lower the pH value. Those who do without peat can benefit from other methods.

Acidify the soil

Why acidify the soil?

Every plant needs a different shape of the earth in which it feels comfortable. This is mainly defined by the natural distribution of the species that owns the soils found there. There are therefore a large number of flowers and fruit-bearing plants that prefer an acidic soil, which is difficult to find in Germany and Central Europe in general. Lime is one of the main culprits here, as lime raises the pH value of the soil and thus provides ideal conditions for local fruit and vegetable varieties. However, some plants in particular, including bog plants, depend on a pH value below 5.5, including the following.

• rhododendron
• Blueberry
• Heather
• Cranberry
• cranberry
• Camellias
• Kiwi fruit
• Japanese azalea
• Rosemary heather
• Broad-leaved Bay rose

This form of soil is particularly necessary when growing blueberries in your own garden. An acidic site is typically achieved by adding peat, but more and more gardeners are foregoing the use of this organic sediment because it is ecologically questionable. For this reason, there are numerous alternatives and methods to lower the soil's pH value and not have to rely on peat.

Note: You should definitely refrain from using vinegar as a remedy, as this will only have negative effects on the soil despite its immediate effect. The acetic acid kills important microorganisms that are essential for the healthy growth of plants.

PH value

Check the pH value yourself

Since the soil in Germany is hardly acidic, it is still worthwhile to determine the pH value of the site before using a peat alternative. This gives you an overview of how acidic, alkaline or ideal your soil is and allows you to determine the dosage of the acidifying agent more precisely. The methods listed below are offered for this purpose.

pH test strips

With special test strips, which are also used for groundwater and irrigation water samples, a very good analysis of the soil quality in terms of acidic and alkaline can be performed. These are used as described below.

• prepare a soil sample that is stretched with water
• dip the strip into it
• wait until the strip changes color
• the color indicates the pH of the soil
• Costs: 3 - 5 euros

soil pH tests

This variant is similar to the test strips, but more precise and takes a little longer. It is also connected to more utensils, all of which are already included in the kit. The instructions are described below.

• take several soil samples from the location from different depths
• mix them well
• put some of the soil in the test tube or container
• add distilled water
• in addition there is the reagent, usually a tablet
• seal the container and give it a good shake
• then a color is displayed
• this color indicates whether your soil is basic or more acidic
• Costs: 6 - 20 euros, Neudorff for example 6 euros

Vinegar and baking soda test

The vinegar and acid test is the variant with the most inaccurate results, but it gives a pretty good overview of whether your soil is acidic or basic.

• to do this, take a sufficient amount of a soil sample
• add acetic acid and baking soda to the soil sample
• if you hear a hissing sound from the baking powder, the sample is more acidic
• if you hear a hissing sound from the vinegar, the sample is more alkaline
• Cost: 0.2 - 2 euros

Note: The higher the value goes in the basic direction, the more treatment is needed to make the soil more acidic. Depending on the means used, this can take several weeks.

Soil analysis

Scientific soil analysis

Of course, you can of course also use a professional soil analysis, but this is associated with higher costs. To do this, simply send a soil sample to a laboratory that specializes in this type of analysis. You will then receive precise information about the existing pH values ​​and can therefore use the appropriate means for processing. Depending on the laboratory, costs are between 50 and 80 euros.

Soil condition

It is advisable to check your own soil in the garden before using a peat alternative and thus to get a more precise picture of the necessary addition. There are two specific types of soil that must be treated differently.

• loose soils, good drainage
• compacted soils, loamy

While loose soil, which is able to absorb and release water effectively, is best enriched with organic materials, the situation is completely different with dense clay soils. Here organic material would make the earth more alkaline and thus do the exact opposite of what is desired. Mineral materials must be used for this so that the compacted soil is adapted, but not changed in its composition or even permanently reduced.

Alternatives to peat

Peat isn't the only material you can use to lower soil pH. Nature provides a multitude of materials that have acidic properties and that work the soil effectively over a period of several days to weeks. They have the advantage that they do not destroy the sensitive bogs from which the peat soil is extracted. Even small amounts of this sediment contribute to the destruction of important flora and fauna habitats and therefore the following alternatives are to be mentioned, which are just as suitable for this without being harmful to the environment be.

• Grape marc
• Coniferous earth
• Special compost
• Oak leaf compost
• Mulch layer
• Coffee grounds mixture
• Iron sulfate
• sulfur

Grape marc

Grape marc is the solid residue of pressed grapes in winemaking. The vegetable residues in the wines are an excellent material for lowering the pH value of the soil, as they contain pure grape acid and fermentation substances. Since the pomace is not produced artificially, it can easily release the acid to the site without destroying important microorganisms. Grape marc can only be obtained from winemakers.

Coniferous earth

It gets easier here with coniferous soil. Coniferous earth means the earth in the direct vicinity of coniferous trees. Conifers have the property of acidifying soils and for this reason it pays to use the coniferous soil around the trunk. You can easily fill in the excavated coniferous soil around the conifer with the garden soil from the planting site.

Special compost

This special compost is an effective mixture of several organic components, which together have an extremely acidic effect. The compost is made up of pieces of coniferous wood, including the bark, needles and wood flour, horn shavings, coffee powder and leaves from chestnuts, oaks and walnuts. These are used together and can then be distributed in the planting soil. In addition, this compost has an extremely good fertilizing effect.

Oak leaf compost

You can also just choose a compost made from oak leaves. Pure oak leaves are extremely acidic and when they decompose, they begin to give off even more acid, which has a positive effect on the soil. Even small amounts of this pure compost have a strong and not negative effect on the earth. In addition, oak leaves are easy to get in Germany, especially if you have one yourself Oak have in the garden.

Mulch layer

This mulch layer consists of a mixture of crushed coniferous wood of different species and also oak leaves. The properties of the conifers are effective even through the wood and are reinforced through the oak leaves. Apply this mulch to the site or soil to a thickness of five centimeters and additionally fertilize with an organic nitrogen fertilizer. Horn shavings are particularly suitable for this.

Special mixture based on coffee grounds

The coffee grounds are an important substance here in order to improve the acidic properties. Together with the coffee grounds, shredded coniferous wood, the associated needles and shredded oak leaves are used. With this variant, too, a nitrogen-based fertilizer must be used to strengthen the effect and at the same time to supply the plants with the necessary nutrients.

Iron sulfate

Iron sulfate is an alternative to peat that can be used primarily for compacted clay soils. Iron sulfate is not an organic substance, but a salt of sulfuric acid. The sulphate acts extremely quickly in the soil and develops an acid that can lower the soil pH by a whole unit within two weeks. The only drawback are possible rust stains on clothes and paths.

sulfur

Sulfur is an element that can also be used for compacted soils and acts there over a period of several months. Sulfur should therefore be used in the previous season so that the soil can be used immediately for planting the plants in the following year.