In addition to the nutrients, the soil conditions are of great importance for plant growth. Here it is crucial whether the soil is acidic or alkaline. This is expressed by specifying the pH value. As a rule, this is between 6 and 7 in the soil. These pH values are ideal for the absorption of nutrients and the living conditions of microorganisms in the soil.
It makes sense to check the pH value annually, as this can also change as a result of so-called "acid rain". Incorrect fertilization can also affect this.
What is the correct way to measure pH?
There are many ways to determine the pH of your soil. The simplest is to take a soil sample, fill it up with distilled water and put a pH test strip (available at drugstores or garden centers) in the mixture. These consist of litmus paper which is orange and changes color depending on the pH value. You can then compare the discolored paper with the color scale on the packaging and thus quickly determine the value. Another option is to buy a soil meter, which digitally displays the pH of your soil. And if you want to know exactly, you can send a soil sample to the laboratory, but this is more complex and, above all, more expensive.
Where should the pH be?
If the soil is too acidic, the pH value is below 6. In this case, the microorganisms living in the soil can no longer break down the organic substances sufficiently, which means that the supply of nutrients is insufficient and the plants are undersupplied. If the pH is above 7, the soil is alkaline. Here, too, not all the necessary nutrients are available to the plants. Above all, boron, phosphorus and manganese are not available here. The absorption of heavy metals (cadmium or lead) is facilitated.
As a rule, the plants feel comfortable at a pH value between 6 and 7, but there are exceptions here too. Some plants prefer a more acidic soil (e.g. heather, rhododendron, busy lizard, hydrangea) and others prefer an alkaline one (e.g. geranium, balloon flower, lavender, hosta).
Change the pH value in a targeted manner
Once you have determined the pH of the soil, you can plant the appropriate plants for this soil quality or improve the soil by deliberately increasing or decreasing the pH (depending on what is desired).
If the soil is too acidic, you can change it by applying garden lime. If the soil is alkaline or if you want to acidify the soil, you can use leaf, bark, or coniferous compost. Organic fertilizer is classified as neutral and supports the soil balance.
Our FARBIO® organic fertilizers support your plants with the ideal nutrient complexes. Specially developed for green plants, fruit plants, vegetable plants and herb plants.
With indoor plants, you should also pay attention to the water quality. Water that is too calcareous increases the pH value and distilled water leads to acidification.