Cold hardiness & minimum temperature

Is Giant Snowflake Bacopa (Sutera cordata)cold hardy? Hardiness zone & min temp

Also called Bacopa, Snowflake Plant, Sutera.

More about giant snowflake bacopa

About Giant Snowflake Bacopa

Sutera cordata · also called Bacopa, Snowflake Plant · flowering

Giant Snowflake Bacopa is a trailing tender perennial producing masses of small white star-shaped flowers on delicate, sprawling stems throughout the growing season. Superb for hanging baskets and container edges. Not listed as toxic by the ASPCA and considered non-harmful to pets.

Cold limit: USDA 9-11 (grown as an annual in most UK and US gardens) · RHS H2 (10-25°C)

Watch for — Bloom pause in heat: Plants stop flowering above 30°C. Move containers to a cooler, shadier position; blooms resume when temperatures drop. Light shearing can help stimulate new growth.

What giant snowflake bacopa's hardiness rating actually means

Hardiness works differently for giant snowflake bacopa: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". Its RHS rating of H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 9-11 (grown as an annual in most UK and US gardens) — 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

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

Concretely, for giant snowflake bacopa as it gets too cold:

Light frost (around 0 to −2 °C) damages or kills tender summer crops outright; cold-hardy types take a few degrees of frost.
The plant does not "survive winter" — its life cycle simply ends, by design, when frost arrives or it finishes cropping.
A surprise late spring frost can also kill young transplants set out too early, before the season even starts.

Can giant snowflake bacopa go outside or overwinter — and where?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost.
In short-season zones, start it indoors or under cover to stretch the effective growing window.
Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

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 giant snowflake bacopa can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline giant snowflake bacopa

Giant Snowflake Bacopa is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks.
Have row cover ready for an unexpected late spring or early autumn frost.
Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.

Giant Snowflake Bacopa hardiness — frequently asked questions

Is giant snowflake bacopa cold hardy?

Hardiness works differently for giant snowflake bacopa: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". A seasonal crop, not a perennial. Giant Snowflake Bacopa is grown 9-11 (grown as an annual in most UK and US gardens); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature giant snowflake bacopa can survive?

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

What hardiness zone is giant snowflake bacopa?

Giant Snowflake Bacopa is rated USDA 9-11 (grown as an annual in most UK and US gardens) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can giant snowflake bacopa survive winter outside?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost. In short-season zones, start it indoors or under cover to stretch the effective growing window. Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

How do I protect giant snowflake bacopa from frost?

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks. Have row cover ready for an unexpected late spring or early autumn frost. Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.