Frost resistance — foam flower, foamflower

For Tiarella, frost resistance is a determining factor in development, as the plant retains evergreen or semi-evergreen foliage in mild climates. In regions with cold winters approaching the limit of frost resistance, the above-ground part may change color to reddish-bronze or die back completely, while the viability of the rhizome is maintained.

In agronomic practice, specific quantitative tissue assessment methods are not applied to this crop; only USDA hardiness zones are used. When grown in containers, the level of frost resistance requires mandatory protection of the root system from pot freezing, which is achieved by moving the plants into unheated spaces.