Cold hardiness & minimum temperature

Is Showy Tick Trefoil (Desmodium canadense)cold hardy? Hardiness zone & min temp

Also called Showy tick trefoil, Canada tick trefoil, Showy tick clover.

More about showy tick trefoil

About Showy Tick Trefoil

Desmodium canadense · also called Showy tick trefoil, Canada tick trefoil · flowering

Desmodium canadense is a tall, robust native perennial wildflower of moist prairies, thicket edges, and open woodland borders across eastern and central North America, from Nova Scotia to Saskatchewan and south to Oklahoma and North Carolina. It produces showy rose-pink to purple pea-like flowers in branched racemes in mid- to late summer, making it one of the most ornamentally valuable of the native tick trefoils for pollinator gardens. It tolerates a broader range of soil moisture than most prairie natives and self-seeds freely. It is not listed as toxic to cats or dogs by the ASPCA, though its seed pods attach to fur and clothing via hooked hairs.

Cold limit: USDA 3-8 · RHS H7 (-35°C to 38°C)

What showy tick trefoil's hardiness rating actually means

Yes — showy tick trefoil is genuinely cold hardy. Rated RHS H7 and USDA 3-8, 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 3-8 — 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. Showy Tick Trefoil is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for showy tick trefoil 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 showy tick trefoil go outside or overwinter — and where?

Plant it out within USDA 3-8 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 showy tick trefoil can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Showy Tick Trefoil hardiness — frequently asked questions

Is showy tick trefoil cold hardy?

Yes — showy tick trefoil is genuinely cold hardy. Rated RHS H7 and USDA 3-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Showy Tick Trefoil is hardy across USDA 3-8; 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 showy tick trefoil can survive?

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

What hardiness zone is showy tick trefoil?

Showy Tick Trefoil is rated USDA 3-8 and RHS H7 — Hardy in the severest European continental winters.

Can showy tick trefoil survive winter outside?

Plant it out within USDA 3-8 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 showy tick trefoil 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.