The table below shows the pH requirements of certain species of plants. It seems that most of the plants require a neutral or slightly acidic soil. If the soil too acidic, one can change its pH by dispersing lime. However, it is very important to be cautious with lime because it may induce alkalosis of the soil, which is always dangerous.
Flowers, trees and shrubs
Name
pH minimum
pH maximum
Abelia
6,0
8,0
Acacia
6,0
8,0
Acanthus
6,0
7,0
Aconitum
5,0
6,0
Adonis
6,0
8,0
Ageratum
6,0
7,5
Ailanthus
6,0
7,5
Ajuga
4,0
6,0
Althea
6,0
7,5
Alyssum
6,0
7,5
Amaranthus
6,0
6,5
Anchusa
6,0
7,5
Androsace
5,0
6,0
Anemone
6,0
7,5
Anthyllis
5,0
6,0
Anthirrhinum
5,5
7,0
Arbutus
4,0
6,0
Arenaria
6,0
8,0
Aristea
6,0
7,5
Armeria
6,0
7,5
Arnica
5,0
6,5
Asperula
6,0
8,0
Aster
5,5
7,5
Avena
6,0
7,5
Azalea
4,5
6,0
Bergenia
6,0
7,5
Buddleia
6,0
7,0
Buphthalum
6,0
8,0
Calendula
5,5
7,0
Camassia
6,0
8,0
Campanula
6,0
7,5
Canna
6,0
8,0
Catalpa
6,0
8,0
Celosia
6,0
7,0
Centaurea
5,0
6,5
Cerastium
6,0
7,0
Cheiranthus
5,5
7,5
Chrysanthemum
6,0
7,0
Cissus
6,0
7,5
Cistus
6,0
7,5
Clarkia
6,0
6,5
Clematis
5,5
7,0
Clianthus
6,0
7,5
Colchicum
5,5
6,5
Aquillegia
6,0
7,0
Convallaria
4,5
6,0
Convolvulus
6,0
8,0
Coreopsis
5,0
6,0
Cornus
5,0
7,0
Coronilla
6,5
7,5
Corydalis
6,0
8,0
Cosmos
5,0
8,0
Cotoneaster
6,5
8,0
Crocus
6,0
8,0
Cynoglossum
6,0
7,5
Dahlia
6,0
7,5
Delphinium
6,0
7,5
Deutzia
6,0
7,5
Dianthus
6,0
7,5
Digitalis
6,0
7,5
Leontopodium / Edelweiss
6,5
7,5
Elaeagnus
5,0
7,5
Enkianthus
5,0
6,0
Erica
4,5
6,0
Euphorbia
6,0
7,0
Forsythia
6,0
7,5
Fuchsia
5,5
6,5
Gaillardia
6,0
7,5
Gazania
5,5
7,0
Genista
5,0
6,0
Gentiana
5,0
7,5
Geum
6,0
7,5
Gladiolus
6,0
7,0
Globularia
5,5
7,0
Godetia
6,0
7,5
Gypsophila
6,0
7,5
Hedera
6,0
7,5
Helianthus
5,0
7,0
Helleborus
6,0
7,5
Hemerocallis
6,0
8,0
Hyacinthus
6,5
7,5
Hydrangea
4,0
5,0
Hypericum
5,5
7,0
Iberis
6,0
7,0
Ilex
5,0
7,5
Ipomoea
6,0
6,5
Iris
5,0
7,5
Juniperus
5,0
6,5
Kalmia
4,5
5,0
Kerria
6,0
7,0
Knipphofia
6,0
7,5
Kolwitzia
6,0
7,5
Laburnum
6,0
7,0
Lathyrus
6,0
7,5
Laurus
5,0
6,0
Lavandula
6,5
7,5
Liatris
5,5
7,5
Lingustrum
5,0
6,5
Lithospermum
5,0
6,5
Lobelia
6,0
7,5
Lonicera
6,0
7,5
Lupinus
5,5
7,0
Magnolia
5,0
6,0
Mahonia
6,0
7,0
Malus
6,0
7,5
Mathiola
6,0
7,5
Molinia
4,0
5,0
Moraea
5,5
6,5
Myosotis
6,0
7,0
Trapaelum / Nasturtium
6,0
7,5
Narcissus
6,0
7,5
Nicotiana
5,5
6,5
Pachysandra
5,0
8,0
Paeonia
6,0
7,5
Papaver
6,0
7,5
Passiflora
6,0
8,0
Paulownia
6,0
8,0
Penstemon
5,5
7,0
Petunia
6,0
7,5
Polygonum
6,0
7,5
Portulaca
5,5
7,5
Primula
6,0
7,5
Prunella
6,0
7,5
Prunus
6,5
7,5
Pyracantha
5,0
6,0
Rhododendron
4,5
6,0
Rhus
6,0
7,5
Rosa / Roses
6,0
7,0
Salvia
6,0
7,5
Saponaria
6,0
7,5
Scabiosa
5,0
7,5
Sedum
6,0
8,0
Solidago
5,0
7,0
Spiraea
6,0
7,5
Syringa
6,0
8,0
Tagetes
5,5
7,0
Tamarix
6,5
8,0
Trillium
5,0
6,5
Tulipa
6,0
7,0
Veronica
5,5
6,5
Viburnum
5,0
7,5
Vinca
6,0
7,5
Viola
5,5
6,5
Wisteria
6,0
8,0
Zinnia
5,5
7,5