In the winter, it's cold outside, and everything is frozen. So you don't need to hide the odor. Same with the fall. The lilac is easy to grow, and nice in the

In the winter, it's cold outside, and everything is frozen. So you don't need to hide the odor. Same with the fall. The lilac is easy to grow, and nice in the spring. So that just leaves the summer, but not many bushes are producing scent in the late summer, anyway.