Lilacs are now coming into bloom, while the forsythia from nearly 4 weeks ago is still yellow, yet fading a bit and sending forth new green growth that contrasts with the remaining flowers. Watching the forsythia bloom throughout the area brought to my attention a misstatement in the previous post, in which it was suggested that pruning forsythia (particularly shearing) in the fall would prevent spring flowering. However, if you watched the forsythia, you too saw that they flower all along the branches, near the ends and in the shrub interior. I saw multiple examples of forsythia that clearly had been sheared to a rounded shape in the fall but were still bright yellow throughout. Seeing this reminded me that forsythia bloom along the length of the branch, and that flowering is probably more dependent on the age of the branch than when it was last pruned. As branches get older, they flower less. This is again why shearing ultimately leads to poor bloom, because the newer growth on the outer shell is relatively short, with old branches continuing from year to year on the inside.
Lilacs, on the other hand, are an example of a spring flowering shrub where incorrect timing of pruning could remove most or all of the next season’s flower display. As can be seen in this photo, the flower buds open at the ends of the prior season’s growth, in comparison to the forsythia photo of the previous post, where flowering is seen into the shrub interior.