One of the most important things when it comes to the best soil to use for the type of plant you intend to grow is the pH value, or acidity level, which corresponds to the concentration of H+ ions in a substance. Depending on the characteristics, some plants require different terrains with diverse levels of acidity below 6.5, which in some cases may even go down to 3.7.
This types of plants are defined as ‘acidophilic’ because of their origin predominantly in the mountains that has led them to adapt to soil will low concentration of positive ions and be fed only in the presence of fund to high acid reaction.
The number of plants included in this category is very high: camellias, hydrangeas, azaleas, magnolias, heathers, gardenias, mimosas, lilies, ferns, blueberries, firs, maples, sequoias, beeces and chestnut trees are just some of the more widespread ones.
If the soil in which they are planted is not acidic enough, the first clear sign of their suffering is the yellowing of leaves (chlorosis) due to the lack of appropriate nutrients that the plant is able to obtain from the soil through the roots and low absorption of iron, which limits the production of chlorophyll (the main colorant pigment).
It is for this reason that even before assessing the correct sun exposure, moisture, temperature and frequency of watering it is essential to know what kind of soil you are going to use and based on that, what species will be appropriate to select.
Generally, acidic soil is widespread in mountainous areas or particularly rainy places, where the base of the mulch is acidic.
How to make soil acidic naturally? Start from here!
First of all, how do you determine with sufficient accuracy the pH of the soil? To answer this question you may use the classic litmus test. Put a bit of soil in a glass of distilled water and soak paper. Alternatively you can use the appropriate kit for the analysis of pH available in specialty stores. If you used soil from a gardening store, the acidity is marked on the packaging.
More difficult, but not impossible, is the process of acidification of soil and the maintenance of the correct levels of acidity. In this case, the best way to proceed is to imitate nature using a series of natural remedies and substances easily available and be paying attention to the water used for watering that must not be too hard, since the limestone lowers the acidity of the substrate. You could use distilled water from a well or even better- rain water. To make the water more acidic you could use a simple trick- add a tablespoon of vinegar per liter of water or half a lemon.
Not only vinegar and lemon juice, but also coca-cola, orange juice, beer, wine and tomatoes can help naturally correct the acidity of the soil. Also reuse of coffee is traditionally a method useful for making the soil acidic. The acidophilic plants also require regular doses of sulfare or iron chelate that solve the problem of non-absorption of iron.
A natural fertilizer used to acidify the soil in a natural way can be found in crushed lupins (that are particularly suitable for citrus fruits) that distributed on the surface of the soil undergo a process of degradation of acid that releases nitrogen slowly.
Mulching acid is also one of the most effective method to better prepare the soil before planting the plants. In this case you can use oak leaves (especially acidic) or sawdust spruce that helps keep the acidity levels constant, ensure the ventilation and soften the soil, making it easy to work.
Even while maintaining the levels of nitrogen it is critical to ensure the survival of acidophilic plants. To do that you can use the soy flour of alfalfa restoring the amount of nitrogen present in the soil. Same effect can be reached with the addition of pine needles, peat moss, black peat or chestnut.