In most parts of the U.S., folks have been staggering through the heat of the summer, desperate for a reprieve from the high temperatures. Good news: September is here! And although it may still technically be summer, the weather is starting to lean a little more autumnal—for many flora, it’s the perfect time to plant.While the cooler months might feel like the end of the growing season, gardeners know that their work is far from over.