Last updated on October 23rd, 2023 at 08:59 pm
Certain plants such as blueberries, hydrangeas or rhododendrons require acidic soil. This raises the question of how to make acidic soil.
In this article you will learn how to make acidic soil and what home remedies are available to lower the soil pH.
Acidic soil can be made from various, organic materials such as bark mulch, oak leaves, coffee grounds, pine or fir needles or grape residue. For this purpose, either a separate acidic compost can be prepared or the materials can be mixed directly into the soil.
Contents
How to get soil acidic?
To get acidic soil, there are different approaches. Follow ways there are to get acidic soil:
- Create acidic compost or bokashi, which decomposes into acidic soil (see instructions below).
- Enrich soil with acidic materials or home remedies (see list of home remedies below).
- Buy peat and mix it into the soil (e.g. this one from Plantop) Buy acidic soil and mix it in (e.g. this one in organic quality from Plantura)
However, the four ways to get acid soil also have different advantages and disadvantages, which I have summarized in the following table:
| Make acidic compost / bokashi | Enrich soil with acidic materials | Buy peat and mix it under the soil | Buy acid soil and mix in | |
|---|---|---|---|---|
| Advantages | Inexpensive, because you can make it yourself You can influence all materials and their quality yourself Environmentally friendly, because also made compost materials | Inexpensive, because you can use waste materials Easy to implement and not very time consuming Environmentally friendly, because also made compost materials | Accurate target pH value easier to achieve Easy to buy and use No own effort for the production | Accurate target pH value easier to achieve Easy to buy and use No own effort for the production |
| Disadvantages | Associated with effort No guarantee for specific pH value | Partially not quite as effective as other approaches One cannot determine the pH value exactly | Associated with costs The extraction of peat is not environmentally friendly, as swamps and bogs have to be destroyed for peat | Associated with costs Acidic soil usually also contains peat, so is also not completely environmentally friendly |
Making acid soil (simple instructions)
To make acidic soil a compost or bokashi should be prepared with acidic compost materials such as coffee grounds, pine needles or other coniferous tree residues, grape waste or grape pomace, or oak and chestnut leaves.
These materials should be mixed in a separate compost or compost box and then sealed as airtight as possible. This can be done with a jute bag, a tarp, or a 5-10cm layer of soil.
Depending on the weather and temperature, the acidic compost should be ready within a few weeks and can be used as soil or mixed in with soil.
To speed up the fermentation process, effective microorganisms (such as these*) can also be added to the acidic composting materials. These will ensure that the organic waste becomes acidic soil or compost even faster.
Make soil acidic with coffee grounds
Soil can easily be made acidic with coffee grounds by repeatedly lightly working dried coffee grounds into the soil or applying them on the surface.
In fact, many plants require a slightly acidic or strongly acidic soil and therefore tolerate coffee grounds very well. In this article, you’ll learn which plants these are.
Acidify soil with vinegar
Soil can also be made acidic with vinegar by making a solution of vinegar and water. If vinegar essence* is used, the mixing ratio should be at least 1:100 and if regular vinegar is used, a ratio of 1:20 is sufficient.
If you use vinegar essence (like this classic variant of Surig*), for example, 1 liter of water should be mixed with 10 ml of vinegar essence, i.e. in a ratio of 1:100.
For normal 5% vinegar, 1 liter of water can be mixed with 50 ml of vinegar.
The vinegar-water mixture can then be spread directly on the soil or around the root.
Lowering soil pH with lemon
Soil pH can also be lowered, at least in the short term, with a lemon. To do this, the juice of one lemon must be mixed with 2 liters of water and applied to the soil.
Since the lemon water is washed out comparatively quickly or its effect decreases, the procedure must be repeated every 10-14 days. Otherwise, the pH value will regulate itself again.
Thus, using lemon water to make acidic soil is not a viable, sustainable option compared to the other home remedies such as pine needles, coffee grounds or grape pomace.
Soil pH lowering home remedies
To lower the soil pH and thus make the soil acidic, there are a number of simple home remedies. The following home remedies can be used to lower soil pH inexpensively and without much effort:
Grape pomace or grape waste is a simple and inexpensive alternative to lower soil pH. Grape pomace has a low pH and at the same time a high nitrogen content, which additionally fertilizes the soil.
Bark mulch can also be used to acidify the soil. This is because bark mulch is usually made from the bark of coniferous trees and thus has a slightly acidic effect
Coffee grounds are a simple home remedy to make acidic soil. Coffee grounds have a low pH and thus can simply be poured on top of the soil or mixed in with normal soil to make this part acidic
Oak leaves or oak leaves are also very good for making acidic soil, because oak leaves are naturally acidic. Just as well, you can make a separate compost only from oak leaves or chopped oak leaves, and then mix it into the soil
Fir or pine needles are another cheap and easy alternative to make soil acidic. This is because conifers naturally have a lower pH. To do this, simply mix fir or pine needles into the soil or let them rot in a separate, acidic compost first.
Chopped coniferous wood can be used as an alternative to pure needles, as all parts of conifers are slightly acidic
To make slightly more acidic soil you can also make an acidic compost (as described in the instructions above). For this purpose, all the home remedies listed above can be used and reduced in size as compost
Lowering the pH of soil or mixing acidic materials with neutral soil usually reduces the nitrogen content at the same time.
However, nitrogen is absolutely necessary for plant growth. Therefore, when making acid soil, care should be taken to apply nitrogen fertilizer at the same time.
This can be done classically with horn shavings (such as this one from Dehner) or alternative, plant-based nitrogen sources such as clover fertilizer (such as this one from Kleepura) or Veggie fertilizer from Neudorff* can be used.
How do you make acid soil for blueberries?
You can make acid soil for blueberries yourself by using an acid compost. To do this, compost different, acidic materials such as bark mulch, oak leaves, coffee grounds, pine or fir needles or grape residue.
Alternatively, these materials can be placed directly under the blueberries on the ground, where they will decompose over time.
However, if you don’t have that long to make a new compost you can play it safe at the beginning when planting the blueberry bushes and buy acidic soil (such as this organic quality one from Plantura*).