Calcifuge

A calcifuge is a plant that does not tolerate alkaline (basic) soil.^[1] The word is derived from the Latin 'to flee from chalk'. These plants are also described as ericaceous, as the prototypical calcifuge is the genus Erica (heaths). It is not the presence of carbonate or hydroxide ions per se that these plants cannot tolerate, but the fact that under alkaline conditions, iron becomes less soluble. Consequently, calcifuges grown on alkaline soils often develop the symptoms of iron deficiency, i.e. interveinal chlorosis of new growth. There are many horticultural plants which are calcifuges, most of which require an 'ericaceous' compost with a low pH, composed principally of Sphagnum moss peat.

A plant that thrives in lime-rich soils is known as a calcicole.

Examples of calcifuges^[2]

Andromeda polifolia Arnica montana Azalea Bilberry Blueberry Calluna (common heather) Camellia Cassiope lycopodioides Cornus florida (dogwood) Corylopsis pauciflora Crinodendron hookerianum Daboecia Desfontainia spinosa Disanthus cercidifolius Embothrium coccineum Enkianthus campanulatus Erica (but not E. carnea or E. erigena)

Fothergilla major Gaultheria mucronata Gentiana acaulis Gentiana sino-ornata Grevillea rosmarinifolia Hamamelis vernalis (spring witch hazel) Illicium anisatum Kalmia latifolia (calico bush) Meconopsis grandis (Himalayan blue poppy) Pieris Some oaks Oat Rhododendron Styrax wilsonii Vaccinium corymbosum

• Carnivorous plants such as sundews, pitcher plants, butterworts, bladderworts, and the Venus Flytrap

References

1. Shorter Oxford English dictionary, 6th ed. United Kingdom: Oxford University Press. 2007. p. 3804. ISBN 0199206872.
2. Collins complete garden manual. United Kingdom: HarperCollins. 1998. p. 336. ISBN 0004140109.