Plants that do not Tolerate Alkaline Soils
(plants that should not be irrigated with graywater)
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Learn more about CSBE's Graywater Project
Soil pH ranges from neutral (7) to acid (below 7) to alkaline (above 7). Extreme pH levels in either direction negatively affect the availability of key nutrients required by plants.
Slightly to Moderately acid soils (<7 to 5) are common to regions with high rainfall and are usually high in organic matter. There are certain plants that prefer a pH slightly below 6. These acid-loving plants should not be irrigated with graywater, which may increase soil alkalinity. Since many of these plants are native to high rainfall regions, many of them are water consuming. The following list provides a selection of such plants.
Botanical name Azalea sp.
English common name ____
Arabic common name ____
Group Evergreen or deciduous shrub
Comment Plant in raised beds in alkaline soils
Botanical name Camellia japonica
English common name Camellia
Arabic common name كاميليا
Group Evergreen shrub
Comment Likes acid soils with plenty of moisture
Botanical name Cornus canadensis
English common name Bunchberry
Arabic common name ____
Group Deciduous carpet plant
Comment Best in acid soils (Cornus mas tolerates alkaline soils)
Botanical name Gardenia jasminoides
English common name Cape Jasmin, Gardenia
Arabic common name جاردينيا
Group Evergreen shrub
Comment Requires acid soils, hard to grow in alkaline soils
Botanical name Ilex aquifolium
English common name English Holly
Arabic common name ____
Group Evergreen shrub or tree
Comment Prefers slightly acid soils
Botanical name Magnolia grandiflora
English common name Southern Magnolia
Arabic common name ماجنوليا
Group Evergreen tree
Comment Gets chlorosis from alkaline soils
Botanical name Magnolia soulangiana
English common name Saucer Magnolia
Arabic common name ماجنوليا
Group Deciduous tree
Comment Gets chlorosis from alkaline soils
Botanical name Nandina domestica
English common name Heavenly Bamboo, Sacred Bamboo
Arabic common name ____
Group Evergreen shrub
Comment Subject to chlorosis in alkaline soils
Botanical name Protea sp.
English common name Protea
Arabic common name ____
Group Evergreen shrub
Comment Most prefer acid soils (Protea neriifolia will grow in alkaline soils)
Botanical name Prunus caroliniana
English common name Carolina Laurel Cherry
Arabic common name ____
Group Evergreen shrub
Comment Often shows salt burn and chlorosis in alkaline soils
Botanical name Rhododendron sp.
English common name ____
Arabic common name ____
Group Evergreen or deciduous shrub
Comment Plant in raised beds in alkaline soils
Botanical name Rosa sp.
English common name Roses
Arabic common name ورد
Group Shrub
Comment Roses grow well in soils ranging from moderately acid to slightly alkaline, but cannot tolerate high alkalinity
Botanical name Taxodium distichum
English common name Bald Cypress
Arabic common name ____
Group Deciduous tree
Comment Takes any soils except slightly alkaline
Botanical name Taxus baccata
English common name English Yew
Arabic common name ____
Group Evergreen shrub or tree
Comment Does not tolerate alkaline soils
Botanical name Tsuga sp.
English common name Hemlock
Arabic common name ____
Group Coniferous evergreen tree and shrub
Comment Grows in acid soils
Botanical name Wisteria sinensis
English common name Chinese Wisteria
Arabic common name وستيريا
Group Deciduous vine
Comment Watch out for chlorosis in alkaline soils