Apr 02, When to Trim Lilac Bushes. Knowing when to trim lilac bushes is important. Most lilacs don’t require pruning until they reach about 6 to 8 feet ( m.) tall. The best time for pruning lilac bushes is right after their flowering has ceased.
This allows new shoots plenty of time to develop the next season of blooms.
Pruning lilacs too late can kill young developing buds. Jun 26, Timing is the Decisive Factor in Pruning Lilacs. If you want to have your blooms next year, it is crucial to prune in those first few weeks after blooming ends. Ideally, this is when you would do maintenance pruning each year. But I get so lazy busy, I end up with a ten foot bush Estimated Reading Time: 4 mins.
If you trim a lilac bush too late in the year, then you’ll cut off unwanted branches and next year’s blossoms. The ideal time to prune is just after the bush finishes blooming for the year. Aug 27, The Lilac borer (or ash borer, a type of clearwing borer moth) tunnels into lilac branches. Signs include sawdust, sap and frass (excrement).
Some plants tolerate this damage. Others experience dieback of branches and sometimes death of the entire plant. People are unlikely to notice them.
Jul 08, If you can't stand the look of your old lilac or you just want a quicker approach, you can take the drastic measure of cutting back the entire plant to about 6 to 8 inches above the ground in the early spring. Fertilize the plant with compost or a balanced fertilizer to prompt new growth. Afraid if I trim it back this fall, it will take another 8 years to flower.
Only place I can have it planted. Townhouse/Small patio. Lilacs set the next seasons blooms right after flowering so the timing of pruning is important. It could be that the late pruning is keeping yours from flowering.