The west side of a patio can remain hot long after the brightest part of the day. A plant labeled for sun may still struggle in a small container against a reflective wall.
Inspect the whole setting
Notice hot paving, dark pots, wind, and how long the afternoon exposure lasts. Check moisture deeper in the mix. Dry roots and overheated roots can both accompany wilt, but adding water to an already saturated pot will not solve a heat problem.
Where practical, shift the container so the root zone receives some protection while the foliage gets suitable light. Move a plant gradually when the difference in exposure is large. A screen or shade cloth can provide temporary protection if installed securely with airflow maintained.
Choose for repeat conditions
For the next planting, select flowers known to handle your local heat and exposure. A larger appropriate container can buffer drying better than a tiny one, though weight and drainage still need considering.
Do routine watering checks early enough to respond before the hottest hours. Avoid making major pruning or fertilizer changes during acute stress. Record whether the plant recovers as conditions cool; that pattern is useful information when deciding whether the location, rather than your attention, is the main difficulty.
Further guidance & source notes
These are background resources, not an endorsement of this website. Regional instructions and the needs of your plant take priority.