pH Preferences

Trees, Shrubs, Vegetables, and Flowers

An accurate soil test will tell you where your pH currently stands and will specify the amount of lime or sulfur that is needed to bring it up or down to the appropriate level. A pH of 6.5 is just about right for most home gardens, since most plants thrive in the 6.0 to 7.0 (slightly acidic to neutral) range. Some plants (blueberries, azaleas) prefer more strongly acidic soil, while a few (ferns, asparagus) do best in soil that is neutral to slightly alkaline. Acidic (sour) soil is counteracted by applying finely ground limestone, and alkaline (sweet) soil is treated with gypsum (calcium sulfate) or ground sulfur.

Common Name	Optimum pH Range
Trees and Shrubs
Apple	5.0-6.5
Ash	6.0-7.5
Azalea	4.5-6.0
Basswood	6.0-7.5
Beautybush	6.0-7.5
Birch	5.0-6.5
Blackberry	5.0-6.0
Blueberry	4.0-6.0
Boxwood	6.0-7.5
Cherry, sour	6.0-7.0
Chestnut	5.0-6.5
Crab apple	6.0-7.5
Dogwood	5.0-7.0
Elder, box	6.0-8.0
Fir, balsam	5.0-6.0
Fir, Douglas	6.0-7.0
Hemlock	5.0-6.0
Hydrangea, blue-flowered	4.0-5.0
Hydrangea, pink-flowered	6.0-7.0
Juniper	5.0-6.0
Laurel, mountain	4.5-6.0
Lemon	6.0-7.5
Lilac	6.0-7.5
Maple, sugar	6.0-7.5
Oak, white	5.0-6.5
Orange	6.0-7.5
Peach	6.0-7.0
Pear	6.0-7.5
Pecan	6.4-8.0
Pine, red	5.0-6.0
Pine, white	4.5-6.0
Plum	6.0-8.0
Raspberry, red	5.5-7.0
Rhododendron	4.5-6.0
Spruce	5.0-6.0
Walnut, black	6.0-8.0
Willow	6.0-8.0

Vegetables
Asparagus	6.0-8.0
Bean, pole	6.0-7.5
Beet	6.0-7.5
Broccoli	6.0-7.0
Brussels sprout	6.0-7.5
Carrot	5.5-7.0
Cauliflower	5.5-7.5
Celery	5.8-7.0
Chive	6.0-7.0
Cucumber	5.5-7.0
Garlic	5.5-8.0
Kale	6.0-7.5
Lettuce	6.0-7.0
Pea, sweet	6.0-7.5
Pepper, sweet	5.5-7.0

Common Name	Optimum pH Range
Vegetables, continued
Potato	4.8-6.5
Pumpkin	5.5-7.5
Radish	6.0-7.0
Spinach	6.0-7.5
Squash, crookneck	6.0-7.5
Squash, Hubbard	5.5-7.0
Tomato	5.5-7.5

Flowers
Alyssum	6.0-7.5
Aster, New England	6.0-8.0
Baby's breath	6.0-7.0
Bachelor's button	6.0-7.5
Bee balm	6.0-7.5
Begonia	5.5-7.0
Black-eyed Susan	5.5-7.0
Bleeding heart	6.0-7.5
Canna	6.0-8.0
Carnation	6.0-7.0
Chrysanthemum	6.0-7.5
Clematis	5.5-7.0
Coleus	6.0-7.0
Coneflower, purple	5.0-7.5
Cosmos	5.0-8.0
Crocus	6.0-8.0
Daffodil	6.0-6.5
Dahlia	6.0-7.5
Daisy, Shasta	6.0-8.0
Daylily	6.0-8.0
Delphinium	6.0-7.5
Foxglove	6.0-7.5
Geranium	6.0-8.0
Gladiolus	5.0-7.0
Hibiscus	6.0-8.0
Hollyhock	6.0-8.0
Hyacinth	6.5-7.5
Iris, blue flag	5.0-7.5
Lily-of-the-valley	4.5-6.0
Lupine	5.0-6.5
Marigold	5.5-7.5
Morning glory	6.0-7.5
Narcissus, trumpet	5.5-6.5
Nasturtium	5.5-7.5
Pansy	5.5-6.5
Peony	6.0-7.5
Petunia	6.0-7.5
Phlox, summer	6.0-8.0
Poppy, oriental	6.0-7.5
Rose, hybrid tea	5.5-7.0
Rose, rugosa	6.0-7.0
Snapdragon	5.5-7.0
Sunflower	6.0-7.5
Tulip	6.0-7.0
Zinnia	5.5-7.0