A
calcifuge is a
plant that does not tolerate
alkaline (basic) soil. 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.
