Cold hardiness & minimum temperature

Is Foamy Bells 'Sweet Tea' (× Heucherella 'Sweet Tea')cold hardy? Hardiness zone & min temp

Also called Foamy bells, Heucherella.

More about foamy bells 'sweet tea'

About Foamy Bells 'Sweet Tea'

× Heucherella 'Sweet Tea' · also called Foamy bells, Heucherella · flowering

Foamy Bells 'Sweet Tea' is a clump-forming, bigeneric Heuchera × Tiarella hybrid grown for cinnamon-to-amber maple-shaped foliage with darker veining. It thrives in part shade, holds colour through cold, and throws airy white flower spikes in late spring. A reliable, evergreen-to-semi-evergreen edger for woodland borders and shaded containers across temperate gardens.

Cold limit: USDA 4-9 (hardy garden perennial) · RHS H7 (-29 to 27°C)

Watch for — Frost heave: Shallow crowns can be lifted out of the ground over winter freeze-thaw cycles. Mulch in autumn and re-firm or replant heaved crowns in spring.

What foamy bells 'sweet tea''s hardiness rating actually means

Yes — foamy bells 'sweet tea' 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. Foamy Bells 'Sweet Tea' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for foamy bells 'sweet tea' 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 foamy bells 'sweet tea' 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 foamy bells 'sweet tea' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Foamy Bells 'Sweet Tea' hardiness — frequently asked questions

Is foamy bells 'sweet tea' cold hardy?

Yes — foamy bells 'sweet tea' 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. Foamy Bells 'Sweet Tea' 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 foamy bells 'sweet tea' can survive?

Minimum survivable temperature is roughly below about −20 °C. Foamy Bells 'Sweet Tea' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is foamy bells 'sweet tea'?

Foamy Bells 'Sweet Tea' is rated USDA 4-9 (hardy garden perennial) and RHS H7 — Hardy in the severest European continental winters.

Can foamy bells 'sweet tea' 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 foamy bells 'sweet tea' 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.