Philadelphia heat wave: Caring for lawn, plants as heat wears on

PHILADELPHIA - This weekend will be the hottest weather we've had in years, so how does that affect the plants and grass around your home?

We talked to the experts to find out when you should mow and when you should water when there's extreme heat.

Philip Watson, a long-time horticulturist on QVC, says late afternoon.

Mowing between 4 and 6 p.m. helps the lawn recover from the shock of a cut. By mowing late afternoon, "The cuts have time to seal before the heat the next day," says Phillip.

By contrast, the morning is the best time to water your lawn. We're talking around sunrise or for an hour or two after sunrise.

That's the time of the day when there is little to no wind and when there's less heat. Less heat means less evaporation of the water. The same is true for less wind. Wind brings in drier air, which accelerates evaporation.

So, watering when there's less heat and little wind allows the water to really wet the soil and penetrate down to the roots of the grass.

When it comes to plants around your yard, the same holds true – watering in the early morning is the best time to give your plants a drink. And, it is the same reason – the most amount of water goes directly to the plants and little is lost to evaporation.

Additionally, while you may decide to let your lawn go dormant in the extreme heat, if you are watering your plants, those that are well-established, meaning three or more years in the ground, may not need as much moisture as often as annuals or vegetables.

Also, plants in containers will need a drink every day to sustain themselves in the oppressive heat, while those in the ground may not need as much water as often.