Gardening & Soil Science

Gardening Soil pH Chart

Unlock nutrient absorption in your garden. Discover the optimal soil pH for tomatoes, lawn grass, and blueberries, plus how soil acidity turns hydrangeas vivid blue.

Select Soil pH Range (Acidic to Alkaline):

Gardening Chemistry Profile

Slightly Acidic (The Vegetable Sweet Spot) (pH 6.0 – 6.8)

Target pH: 6.0 – 6.8

Thriving Plants & Crops:

Tomatoes, Peppers, Potatoes, Strawberries, Cucumbers, Carrots, Roses, Fruit Trees, Lawns.

NPK Nutrient Availability:

Maximum bioavailability of the Big Three (Nitrogen, Phosphorus, Potassium - NPK) plus trace minerals.

How To Amend / Adjust:

Maintain by adding compost and aged organic mulch annually.

Garden Hazard Warning:

Over 85% of backyard garden vegetables and turf grass thrive in this golden zone.

The Hydrangea Color Hack: How Soil pH Changes Petal Colors

Deep Blue / Purple

Soil pH < 5.5 (Acidic) + soluble aluminum available to roots.

Vibrant Pink / Red

Soil pH > 6.5 (Alkaline). Roots cannot absorb aluminum, keeping petals naturally pink.

White Hydrangeas

White cultivars (Annabelle) have zero anthocyanin pigment; soil pH does NOT change their color!