By Phran Novelli

PHILADELPHIA (CBS) - Does wilting mean watering? That depends. When you see plants with droopy leaves – look at the time of day.

Lots of plants, such as hydrangeas, will lower their leaves in the heat of the day, to shade the back of their leaves from the sun. The back of the leaf is where the pores are that evaporate moisture, so drooping reduces a leaf’s exposure so it can hold more moisture. So, if you see wilting, check later on to see if the leaves perk up by evening or the next morning – hydrangeas often do that, and then you know they’re OK for another day. On the other hand, if your plant is wilting first thing in the morning, it hasn’t rained in weeks, or you just planted it this year, then you’re probably right to get out the hose.

To be sure, poke a finger a few inches down into the soil to see if it’s dry. If it is, put the hose next to the base of the plant on a slow trickle for an hour or two, so the water can slowly seep deeply into the soil. Watering deeply helps roots grow down to find moisture – and those deeper roots will help make your shrub more drought-resistant in the future.