It’s wilting season—the time of year when days are long and temperatures are high. You can stay home and water those shrinking violets, or choose some seriously stand-up plants. This is where knowing a plant’s origin comes in handy. It stands to reason Iceland poppies won’t stay as perky as New Zealand flax in the midst of a heat wave.

Even heat lovers are vulnerable to hot, sunny days

You can’t go wrong with the typical annuals you’ll find at your local garden center. But even heat-lovers like Salvia, Lantana and Petunia will sulk in the hot sun until they settle in. Plants that are perky in the pots they came in will become sulky when replanted in the ground or in a container if the temperatures soar along with the sun.

The one-two punch of the sun-temp combo can do a number on unsuspecting plants. When days are cool and moist, even shade-lovers will tolerate some sun. And here’s where it takes me by surprise. Every year, the potted cane Begonia that was enjoying a few hours of early summer sun suffers serious sunburn, its topmost leaves shriveling up and turning black everywhere the sun touches them.

A decorative sage (Salvia splendens ‘Van Houttei’) that prefers shade went into a long-term wilt where it was planted, recovering only slightly as the days cooled off. Luckily, the heatwave only lasted two days. As soon as temps dipped back into the mid-80s, I dug it up and planted it in a more suitable spot. I had been overly optimistic about it being versatile enough to enjoy several hours of direct sun (it isn’t).

Plant in the cool of the evening

Whether you’re planting or repotting this time of year, it’s best to do it toward the end of the day. Water new or transplanted plants in well. They’ll have the dark of night for a stress-free rest before the baking sun finds them the next day. Make sure the water soaks into the ground beneath and surrounding the plant.

The second best time to plant in the heat of summer is early morning. But for that choice, find something to shade the area afterward, especially if it’s a hot, sunny day. Anything from an old umbrella to a small patio table will give some shelter to small areas. If you’re planting a large area in the blazing sun, just make sure they’re watered in well and mulched to slow evaporation of the soil surface.