Flowers can typically sit in a car for no more than two hours under moderate temperatures. However, this is a general guideline and the actual timeframe is highly dependent on the car's interior temperature, which can become dangerously hot or cold very quickly. Extreme temperatures are the primary enemy of cut flowers, causing them to wilt, dehydrate, and die prematurely.
The critical factor isn't just time, but the microclimate inside your vehicle. On a mild 72°F (22°C) day, the inside of a parked car can reach over 110°F (43°C) within an hour. This heat accelerates water loss through a process called transpiration, where flowers lose moisture through their petals and leaves. Cold weather below 40°F (4°C) can cause cell damage, turning petals translucent and mushy.
How Temperature and Time Impact Fresh Cut Flowers
| Condition | Approximate Max Safe Duration | Primary Risk | Visible Signs of Damage |
|---|
| Parked Car, Summer (90°F+/32°C+) | 10 - 30 minutes | Rapid dehydration & heat shock | Wilting, drooping, burnt petals |
| Parked Car, Mild Day (60-75°F/15-24°C) | 1 - 2 hours | Gradual dehydration | Slight wilting, loss of vibrancy |
| Running Car with AC/Heat Control | Several hours | Minor stress | Minimal if kept comfortable |
| Parked Car, Freezing (Below 32°F/0°C) | Less than 30 minutes | Cell freeze & rupture | Translucent, slimy petals upon thawing |
To maximize their lifespan, always transport flowers in a climate-controlled car cabin. If you must leave them in the car briefly, place them out of direct sunlight, ideally in the footwell where it's cooler, and make the stop your absolute last errand. For the best results, flowers should be the final item you pick up before heading directly to their destination.
