Cold hardiness & minimum temperature

Is Candy Stripe Creeping Phlox (Phlox subulata 'Candy Stripe')cold hardy? Hardiness zone & min temp

Also called Candy Stripe Creeping Phlox, Candy Stripe Moss Phlox.

More about candy stripe creeping phlox

About Candy Stripe Creeping Phlox

Phlox subulata 'Candy Stripe' · also called Candy Stripe Creeping Phlox, Candy Stripe Moss Phlox · flowering

A striking cultivar of moss phlox producing masses of white flowers with a distinct pink stripe through each petal in mid-spring. Evergreen, needle-like foliage forms a dense, weed-suppressing carpet year-round. Excellent for rock gardens, slope stabilisation, and trailing over walls. Cold-hardy and low-maintenance. ASPCA-confirmed non-toxic to cats, dogs, and horses.

Cold limit: USDA 3–9 · RHS H6 (-29–35°C)

Watch for — Root rot in poorly drained soil: Wilting or blackened stems at the base indicate root rot from waterlogged conditions. Ensure excellent drainage at planting; remove affected areas, improve soil drainage with grit, and avoid replanting in the same spot. Most cases occur after wet winters.

What candy stripe creeping phlox's hardiness rating actually means

Yes — candy stripe creeping phlox is genuinely cold hardy. Rated RHS H6 and USDA 3–9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 3–9 — 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 about −20 to −15 °C. Candy Stripe Creeping Phlox is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for candy stripe creeping phlox as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 candy stripe creeping phlox go outside or overwinter — and where?

Plant it out within USDA 3–9 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 candy stripe creeping phlox can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Candy Stripe Creeping Phlox hardiness — frequently asked questions

Is candy stripe creeping phlox cold hardy?

Yes — candy stripe creeping phlox is genuinely cold hardy. Rated RHS H6 and USDA 3–9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Candy Stripe Creeping Phlox is hardy across USDA 3–9; 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 candy stripe creeping phlox can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Candy Stripe Creeping Phlox is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is candy stripe creeping phlox?

Candy Stripe Creeping Phlox is rated USDA 3–9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can candy stripe creeping phlox survive winter outside?

Plant it out within USDA 3–9 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 candy stripe creeping phlox below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.