CALCIFUGE - A tree which will not thrive in alkaline soil. These plants are also described as ericaceous.

These plants require an amount of iron in their diet which is present in less quantity in alkaline soil, consequently, calcifuges grown on alkaline soils often develop the symptoms of iron deficiency as can be seen for example by the yellowing of leaves of Azalea (Rhododendron). Many bonsai growers add sequestered iron to the soils of calcifuge plants.

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