What winter does to plant shipping
The standard winter warning — "never order plants when it freezes" — gets repeated every December as if it were advice. It is not advice; it is a scheduling problem, and scheduling problems have solutions. Three winter boxes have come through Brno since January: two from Asian farms, one from an EU nursery, and each failed or survived for reasons the box could have told you in advance.
Where the cold actually gets in
Plants almost never freeze in transit. They freeze at the gaps: the sorting depot conveyor over a weekend, the courier van unloaded at 6 a.m. while the driver breakfasts, the post-office pickup window where your box sits by the door for four hours. A 40-minute cold snap to −5 °C is survivable for most plants; eight hours is not. The heat pack decides none of this — where the box waits does.
Heat packs, used properly
The Asian farms pack a 40-to-72-hour heat pack under the plants, held off the tissue by crumpled paper so it bakes nothing. The EU nursery shipped mine with none — and did not need one: emersed pots in insulated sleeve boxes rode a heated courier chain the whole way. The pack you should worry about is the one stuck directly against leaves for three days; I have received steamed rotala that cooked under its own heater.
Timing beats packaging
Ship Monday to Wednesday, never Friday — a box that misses the last van Thursday night sleeps in an unheated depot for the weekend, and January weekends are long. Skip ordering entirely in the two weeks around the winter holidays, when courier networks run at half staff and every box takes the scenic route. My one total-loss box shipped December 27th. Nobody was at fault; the calendar was.
Acclimation on arrival
Cold boxes need to rest sealed at room temperature for six to eight hours before opening — pulling plants out of a 4 °C bag into a 24 °C room shocks them harder than the cold itself. Trim anything translucent, float the survivors shaded for two days, then plant. The survival difference between opening immediately and waiting is not subtle.
Whatever survives arrival will bring passengers — see the hitchhiker census before that box goes anywhere near your display.
Tropical shippers fight rot; winter shippers fight the waiting rooms. Every failure box I have opened died in a queue, not on the road.