Q: My neighbors haul away their pine needles, yet I see bales of pine straw for sale. Are pine needles a smart choice for mulching if your garden does not have pine trees in it? Will the pine needles change the pH level of the soil?
A: My favorite material for mulching and building garden paths is white pine needles (Pinusstrobus). They feel soft enough to walk on with your bare feet, they do a remarkable job at weed suppression and water retention and they can be easily crumbled into smaller pieces for use in container gardens. The needles interlock, so they don’t wash away, making them ideal for mulching sloped garden areas. They tend to break down more slowly than other organic mulch options.
Despite all the positive traits of pine straw, this superb organic mulching material still has a bad reputation, likely linked to pH. In truth, the amount of acidity released from fallen brown needles is negligible. Even green needles, which are seldom used as mulch, have a low pH level that is quickly leached away with rain and exposure to the elements. So go ahead—mulch with pine straw and worry not.