The official start to fall is less than a month away, but some trees around the Pittsburgh area are already starting to show color. This color isn't traditional fall foliage though. 

Most of western Pennsylvania's fall color and fall leaf drops will still come later in the year. But tree experts said that when trees are really stressed due to heat and drought, they're going to go into their fall foliage and fall colors a little bit earlier.

Changing leaves are sign of heat stress  

"The trees, when they have a lack of water, they kind of have to prioritize what that water is going to. So as far as chlorophyll production, photosynthesizing, that type of thing, a lot of times it can result in some early leaf change in color, and even, like, a dull fall color," Luke Werner, the district manager at Davey Tree Expert Company in Gibsonia, said. 

After a wet spring and first half of summer, conditions quickly dried out in mid-July. This sudden drop in precipitation accompanied by heat stressed out some trees. There are certain trees that more readily reveal symptoms of heat and drought stress. These include birch, willows and maples.

"Red maples, for instance, are a very common shade tree in our area, and they're also a very common street tree. So these are plants that people are putting in their front yards or along streets," Werner pointed out. "Well, those paved surfaces also reflect and retain heat. So trees in parking lots that you might see in shopping plazas and shopping areas that are in, you know, these large concrete islands, they may be showing drought and heat stress much earlier than other ones."

How to combat heat stress on your trees

To combat heat and drought stress, try to have a consistent watering schedule throughout the year. Make sure to add supplemental watering to your schedule when drought emerges. Also, make sure you're watering out to the drip line on your tree - or an imaginary line from the end of the tree's branches down to the ground. 

Lastly adding a few inches of mulch ideally out to the drip line can help mitigate the soil temperature and moisture in the area surrounding the tree.