Understanding Soil pH
Soil pH tells you how acidic or alkaline your soil is.
It affects how available nutrients are to plant roots.
The pH Scale
The scale runs from:
- 0 to 14
A pH of:
- 7 is neutral
- Below 7 is acidic
- Above 7 is alkaline
What Most Vegetables Prefer
Many vegetables grow best around:
- pH 6.0–6.8
This range keeps many essential nutrients available.
Why pH Matters
Even if fertilizer is present in the soil, roots may not be able to use nutrients effectively if pH is too high or too low.
This is called nutrient lockout.
Acid-Loving Plants
Some plants prefer much lower pH.
Blueberries are a classic example and often perform best around:
- pH 4.5–5.5
That is too acidic for many vegetables.
Raising Soil pH
Lime is commonly used to raise pH.
Types may include:
- Calcitic lime
- Dolomitic lime
Apply only according to soil-test recommendations.
Lowering Soil pH
Sulfur-based amendments are often used to lower pH.
This process takes time.
Do not expect an instant change.
Alabama Soils
Many Alabama soils are naturally acidic, but local conditions vary.
Previous liming, construction, irrigation water, and native geology can all affect pH.
Don’t Chase a Perfect Number
A garden at pH 6.3 does not need to become exactly 6.5.
Plants tolerate ranges.
The goal is a healthy range, not a mathematically perfect result.
GardenGrowz Tip
Never adjust soil pH based only on appearance.
Test first.