Cold hardiness & minimum temperature

Is Sugar and Spice Tiarella (Tiarella 'Sugar and Spice')cold hardy? Hardiness zone & min temp

Also called Sugar and Spice foamflower, deeply-lobed foamflower.

More about sugar and spice tiarella

About Sugar and Spice Tiarella

Tiarella 'Sugar and Spice' · also called Sugar and Spice foamflower, deeply-lobed foamflower · flowering

Sugar and Spice is a showy clumping foamflower with large, deeply and intricately lobed glossy green leaves marked by a strong dark central pattern. In late spring it bears full, fragrant-looking spires of pink-budded white flowers held well above the foliage. One of the more ornamental Tiarella hybrids, it earns its place for both bold leaves and a generous bloom.

Cold limit: USDA 4-9 (hardy garden perennial) · RHS H7 (-34 to 24°C)

Watch for — Crown rot: Cold, wet, poorly drained soil rots the crown in winter. Plant in well-drained humus-rich soil and prevent water from pooling.

What sugar and spice tiarella's hardiness rating actually means

Yes — sugar and spice tiarella is genuinely cold hardy. Rated RHS H7 and USDA 4-9 (hardy garden perennial), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 4-9 (hardy garden perennial) — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly below about −20 °C. Sugar and Spice Tiarella is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for sugar and spice tiarella as it gets too cold:

It tolerates winter lows to about −20 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can sugar and spice tiarella go outside or overwinter — and where?

Plant it out within USDA 4-9 (hardy garden perennial) and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when sugar and spice tiarella can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Sugar and Spice Tiarella hardiness — frequently asked questions

Is sugar and spice tiarella cold hardy?

Yes — sugar and spice tiarella is genuinely cold hardy. Rated RHS H7 and USDA 4-9 (hardy garden perennial), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Sugar and Spice Tiarella is hardy across USDA 4-9 (hardy garden perennial); it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature sugar and spice tiarella can survive?

Minimum survivable temperature is roughly below about −20 °C. Sugar and Spice Tiarella is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is sugar and spice tiarella?

Sugar and Spice Tiarella is rated USDA 4-9 (hardy garden perennial) and RHS H7 — Hardy in the severest European continental winters.

Can sugar and spice tiarella survive winter outside?

Plant it out within USDA 4-9 (hardy garden perennial) and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to sugar and spice tiarella below its minimum temperature?

It tolerates winter lows to about −20 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.