Acidic Soil Ph: Determine and Regulate

Acidic Soil Ph: Determine and Regulate

With intensive farming, the land on the site acidifies over time. Not all plants like acidic soils. Rather, the opposite is true. What to do?

Soil acidity – the ability of the soil to exhibit the properties of acids. It is best to grow plants in neutral soil (pH 7). With increased acidity of the soil, as well as with its alkalization, some nutrients become unavailable or inaccessible to plants. At the same time, the efficiency of fertilizers applied to the soil also decreases.

Why is acidic soil harmful? Too high acidity (pH below 5.0) of the soil leads to the fact that many nutrients pass into a state in which they cease to be absorbed by plants. In addition, the activity of many beneficial bacteria and fertilizers stops.

Why are alkaline soils harmful? On alkaline soils (pH above 7.5), plants develop poorly, and their leaves turn yellow because they cannot receive iron (it simply cannot be absorbed).

It is important to understand that soil acidity can change over time. Most often this happens due to watering when minerals are gradually washed out of the soil. If the water is soft, then the acidity in this case increases, and if it is hard, it decreases.

The best ph of soil for cultivation

This is not to say that acidity is good or bad. Some plants like acidic soil, others don’t. For example, we have collected the most popular garden crops and the most suitable pH for them.

Soil acidity table for vegetables and berries and other garden plants

Neutral soil (pH 6.5-7.5) Weakly acidic soil (pH 5.5-6.5) Medium acidic soil (pH 4-5.5) Strongly acidic soil (pH less than 4)
Artichoke Basil Beans Cowberry
Broccoli Eggplant Pear Blueberry
Cherry Soybeans Potato Honeysuckle
Brussels sprouts Peas Strawberry Viburnum
White cabbage Melon Flax Cranberry
Red cabbage Zucchini Pepper Raspberries
Cabbage Cauliflower Tobacco Juniper
Kohlrabi Gooseberry Pumpkin Rowan
Onion Corn Rosemary Blueberry
Carrot Leek Fennel Sorrel
Sea buckthorn Shallot
Parsley Raspberries
Millet Melissa
Wheat Mint
Radish Oats
Rice Cucumbers
Beet Squash
Currant Tomatoes (tomatoes)
Plum Radish
Asparagus Turnip
Apple tree Rye
Jerusalem artichoke
Extragon (tarragon)

Soil acidity table for garden flowers

Neutral soil (pH 6.5-7.5) Weakly acidic soil (pH 5.5-6.5) Medium acidic soil (pH 4-5.5)
Building Amaryllis Azalea
Aster Pansies Heather
Marigold Begonia Gamamelis
Carnation Carnation Calla
Geranium Gerbera Camellia
Gladiolus Hydrangea Lily of the valley
Alfalfa Delphinium Lily
Poppy Iris Rhododendron
Primrose Narcissus Violets
the Rose Marigold
Chrysanthemum Fern
Cyclamen Primula

Soil acidity table

Acidity of black soil Acidity of vegetable soil Acidity of fertile soil High-moor peat acidity Lowland peat acidity Acidity of peat soil
5.5-7.8 4.0-6.0 4.0-6.0 2.8-5.0 4.5-6.0 2.8-3.6

If you know the type of soil in your area, find it in the table below. Under its name, you will see the pH level. Thus you can determine which district asthenia better take root in your soil.

Determine the acidity of the soil

Method 1

To determine the acidity of the soil in your area, it is not at all necessary to call specialists. You can simply purchase a universal litmus paper from the pharmacy and take several soil samples from the site. Each of them should be wrapped in pieces of dense cloth and placed in separate glasses of water (the ratio of water to soil is 1: 1). It is best to take distilled water or rainwater.

After 5 minutes, place a litmus paper in each container. This must be done very quickly: just dip a piece of paper in water for 1-2 seconds or apply a drop of liquid on it. The indicator paper will change color, by which you can determine the acidity of a particular soil sample. As a rule, an acidity scale is attached to the indicator paper.

Soil acidity scale
Soil acidity scale

Method 2

You can determine the acidity of the soil on the site by conducting a simple experiment. To do this, you need to pour 1 tsp. ground on glass and drizzle with a little 9% vinegar. In this case, it is advisable to put the glass on a dark surface so that the result is clearly visible.

  • A lot of foam has formed – the soil is alkaline;
  • there is foam, but not very much – the soil has a neutral reaction;
  • there is no foam at all – the soil is acidic.

Method 3

In some cases, increased acidity can also be detected by external signs:

  • acidic podzolic soils are whitish;
  • on the site, weeds that are resistant to the acidity of the soil feel good: creeping buttercup, whitewort, pickle, field coryza, pike (meadow);
  • acidic soils are very fond of moss;
  • clover or alfalfa grow poorly, wheat does not winter.
Acidic Soil Ph
The appearance of moss on the site is a clear sign of an increase in soil acidity.

An indicator of the type of soil in the garden can be regular beetroot. The color of its leaves and petioles will tell you what soils we are dealing with:

  • beets have grown with red leaves – the soil is acidic;
  • red streaks on the leaves – slightly acidic soil;
  • green leaves with red petioles – the soil is neutral.

Soil liming methods

To reduce the acidity of the soil, it needs to be limed. This can be done in several ways. Let’s take a look at each of them.

Slaked lime (or fluff). It is a white powder that dissolves well in water and neutralizes soil acidity in a very short time. With increased acidity, 0.5 kg of lime is added per 1 square meter, with an average degree of acidity – 0.3, and with a weak one – 0.2 kg.

Dolomite flour. This drug does not work as fast as lime, but it allows you to increase soil fertility due to the content of calcium carbonate and magnesium carbonate in its composition. In acidic soil, 0.5 kg of dolomite flour per 1 sq. .m.

Dolomite flour is a great way to reduce soil acidity
Dolomite flour is a great way to reduce soil acidity

Chalk. Finely ground chalk is also a great way to reduce soil acidity. With high acidity indices per 1 square meter, 0.3-0.7 kg of chalk should be introduced, if the level is average – 0.2-0.6 kg, with low – 0.1-0.4 kg.

Wood ash. The substance contains calcium, as well as potassium, phosphorus, and other trace elements useful for plants. Wood ash is best used on sandy soils or peat bogs. It is introduced into the soil at the rate of: 0.4-0.5 kg per 1 square meter with increased acidity, 0.2-0.3 kg per 1 square meter with medium acidity, 0.2 kg with weak soil acidity.

The rates of application of lime-containing preparations also depend on the composition of the soil. Light soils require lower doses of preparations compared to heavy clay soils.

How to lime the ground in a summer cottage

If the soil is very acidic, it is necessary to add substances containing lime gradually (especially for light soils). They are evenly distributed over the soil surface, without mixing to the depth. The lime application intervals should be 1-2 years.

If the soil is heavy – clay or loamy – then the required dose of lime can be applied at a time. It is best to do this in the fall, and then dig up the beds.

Lime should not be applied along with manure. In this mix, insoluble compounds are obtained that cannot be absorbed by plants.

Crops such as beans, peas, cucumbers, pumpkin, carrots, tomatoes, parsley, rutabaga, and celery do not thrive on limed soil. Therefore, chalk, dolomite flour, or slaked lime under them must be brought in ahead of time, at least a year in advance.

Every gardener who wants to grow a good crop and is used to taking care of his plot should control the acidity of the soil.


  1. M

    Melissa on October 2021

    But how to bring the alkaline soil to neutral, but already with planted plants? I planted lilies and did not control the pH (((Now the poor things, some did not germinate, and those that germinate turn yellow (((

    1. L

      Lora on October 2021

      Good afternoon, Melissa. Pour on soil a solution of citric acid.

  2. D

    Debbie on October 2021

    Good article, But there are crops that need acidic soil. How to make it sour. Watering with acidic water has no effect. (The blueberries are yellow all summer, and the petioled hydrangea has stopped growing)

    1. D

      Diana on October 2021

      Hi, Debbie! If you have not laid acidic soil for these crops in the planting pits (soil from under the pines, for example), then now you can acidify it either with special fertilizers, there are a lot of them on sale, both granulated for a single application in spring and autumn, and liquid, or mulching with coniferous litter or high-moor peat.

  3. J

    Jennifer on October 2021

    Please help me understand what kind of soil is on my site. Horsetail, plantain, clover grow well from weeds, the soil is covered with green moss. I thought that the soil was acidic, but I applied litmus and, according to the table, it turned out to be 7-8 units, that is, the soil is neutral, slightly alkaline. So what’s the pH of the earth?

    1. L

      Linda on October 2021

      Good afternoon, Jennifer! How did you take the sample? To get the correct result, you need to take the ground at a depth of 20-25 cm, moisten it, and then measure it. Be sure to repeat the test in several different places – 5-6. And only on the basis of the average mark to draw conclusions.


Leave a Reply