pH Levels in Soil
Soil pH is defined as "measure of the acidity or alkalinity in soils." and states it's importance as such: "It specifically affects plant nutrient availability by controlling the chemical forms of the nutrient."
Some sources of acidity include, but are not limited to, rainfall, fertilizer, acid rain, decomposition of organic material, and mine spoil.
Regions with heavy rainfall are often known for their high level of acidity in the soil, as the water reacts with the CO2 in the atmosphere that forms carbonic air. Rainfall has a slightly acidic pH of 5.7.
Micro organisms release CO2 when decomposing organic matter which, when mixed with soil water, can form carbonic acid.
Alkaline soils (classified alongside saline soil and sodic soil) are usually caused by high salt concentrations, "with saline soils being dominated by calcium and magnesium salts and sodic soils being dominated by sodium", with alkaline soils being characterized by the presence of carbonates. Soil in areas with limestone near the surface are known to be alkaline from the calcium carbonate in the limestone.
Some sources of acidity include, but are not limited to, rainfall, fertilizer, acid rain, decomposition of organic material, and mine spoil.
Regions with heavy rainfall are often known for their high level of acidity in the soil, as the water reacts with the CO2 in the atmosphere that forms carbonic air. Rainfall has a slightly acidic pH of 5.7.
Micro organisms release CO2 when decomposing organic matter which, when mixed with soil water, can form carbonic acid.
Alkaline soils (classified alongside saline soil and sodic soil) are usually caused by high salt concentrations, "with saline soils being dominated by calcium and magnesium salts and sodic soils being dominated by sodium", with alkaline soils being characterized by the presence of carbonates. Soil in areas with limestone near the surface are known to be alkaline from the calcium carbonate in the limestone.
pH Levels For Each Plant (from acid to alkaline):
Rat Root: 3.5 - 4.4 (due to Rat Roots love of moist soils, I've guessed that it prefers acidic soils, due to the correlation between heavy rainfall and soil acidity)
Devil's Snare: 4.5 - 5.0 (Scottish Highlands are known to have acidic soil)
Bubotuber: 4.5 - 5.0 (also from Scotland)
The Mandrake: 4.5 - 5.0 (based on them being sighted near areas associated with death and their prevelance in European countries, it is safe to assume Mandrakes enjoy acidic soils)
Leaping Toadstool: 4.5 - 5.0 (due to their presence in the Forbidden Forest, we can assume they're prevalent in Scotland)
Valerian Root: 4.5 - 5.0
Lily Plants: 5.5 - 6.5
English Rose: 5.5 - 7.0
Fluxweed: 5.6 - 7.8 (being a member of the mustard family, it's harder to pinpoint this plant's pH soil preference, as mustard plants are found in both acid-based and alkaline-based soils)
Lovage: 6.1 - 6.5
Asphodel: 6.1 - 6.5
Shrivelfig: 6.1 - 6.5 (due to their origin being from Abyssinia, Ethiopia the acid level can be concluded to be neutral to slightly acidic)
Knotgrass: 6.1 - 7.3
Nettle: 6.1 - 7.8
Nux Myristica: 6.1 - 7.3 (a member of the nutmeg family, it's levels are derived from the nutmeg's)
Snakeweed: 6.1 - 8.4
Peppermint: 6.6 - 7.3
Poppy Heads: 6.6 - 7.3
Dittany: 6.6 - 7.3
Bouncing Bulb: 6.6 - 7.3
Silverweed: 7.4 - 7.8
Motherwort: 7.4 - 7.8
Gurdyroot: 7.4 - 7.8 (while never actually stated, Gurdyroots thrive in nutritious soil, so this level of acidity would be my best guess)
Aconite: 7.4 - 7.8 (same as above)
Gillweed: 7.9 - 8.4
Wormwood: 7.9 - 8.4 (prefers salty soil)
Rat Root: 3.5 - 4.4 (due to Rat Roots love of moist soils, I've guessed that it prefers acidic soils, due to the correlation between heavy rainfall and soil acidity)
Devil's Snare: 4.5 - 5.0 (Scottish Highlands are known to have acidic soil)
Bubotuber: 4.5 - 5.0 (also from Scotland)
The Mandrake: 4.5 - 5.0 (based on them being sighted near areas associated with death and their prevelance in European countries, it is safe to assume Mandrakes enjoy acidic soils)
Leaping Toadstool: 4.5 - 5.0 (due to their presence in the Forbidden Forest, we can assume they're prevalent in Scotland)
Valerian Root: 4.5 - 5.0
Lily Plants: 5.5 - 6.5
English Rose: 5.5 - 7.0
Fluxweed: 5.6 - 7.8 (being a member of the mustard family, it's harder to pinpoint this plant's pH soil preference, as mustard plants are found in both acid-based and alkaline-based soils)
Lovage: 6.1 - 6.5
Asphodel: 6.1 - 6.5
Shrivelfig: 6.1 - 6.5 (due to their origin being from Abyssinia, Ethiopia the acid level can be concluded to be neutral to slightly acidic)
Knotgrass: 6.1 - 7.3
Nettle: 6.1 - 7.8
Nux Myristica: 6.1 - 7.3 (a member of the nutmeg family, it's levels are derived from the nutmeg's)
Snakeweed: 6.1 - 8.4
Peppermint: 6.6 - 7.3
Poppy Heads: 6.6 - 7.3
Dittany: 6.6 - 7.3
Bouncing Bulb: 6.6 - 7.3
Silverweed: 7.4 - 7.8
Motherwort: 7.4 - 7.8
Gurdyroot: 7.4 - 7.8 (while never actually stated, Gurdyroots thrive in nutritious soil, so this level of acidity would be my best guess)
Aconite: 7.4 - 7.8 (same as above)
Gillweed: 7.9 - 8.4
Wormwood: 7.9 - 8.4 (prefers salty soil)
Global variation in soil pH. Red = acidic soil. Yellow = neutral soil. Blue = alkaline soil. Black = no data.