lilac with butterfly by andrealeev
I have planted all my lilacs near some other big shrub or tree because my property is mostly wooded or has something growing on it- I have little choice of where to plant plants that I want. I know that lilacs do NOT like their roots crowded; but I have few options. I had planted the lilac that is blooming near the Rose of Sharon when they were little, so though they are all huge, perhaps the roots would have had a better chance to establish themselves when the shrubs were all small.
The lilac that has a few flowers is near a crape myrtle and who knows what size the crape myrtle roots are (compared to the Rose of Sharon roots.) I do wish someone would do a study of roots of plants and have diagrams and size charts so we gardeners can know what is underground as well as what we can see.
I do not fertilize my lilac trees, I know that too much nitrogen is not good for lilacs to flower. My mother used to put chicken manure around the shrubs. I think I am going to try some worm castings.
I must admit to being careless about checking the pH in the areas where the lilacs aren’t blooming. One is always smarter about what is wrong when one is armed with numbers. Lilacs prefer soil with a pH between 6.5 and 7.0. The bushes may suffer if the pH is either too high or too low, as the nutrients they need to thrive may not be readily available from the soil.
One aspect that this GardenLady has no control over is the coldness of the winters. Since I do not know the types of lilacs my friends gave me, I know that some traditional varieties of lilacs rely on cold winters to promote blooming and the winters here are getting warmer.