Dec 10, Cut spent flower heads off after the lilac has finished blooming, when one or two new shoots become visible under the flower cluster. Make the cut just above a. 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. Late spring: Cut the tallest canes to the ground. Thin out excess suckers. Shorten any remaining cane to allow it room to grow un-cut the rest of the summer. Below, left: In year three the dwarf lilac blooms well and is the right size for this bed.
Below, right: A few weeks after it blooms, we cut out the tallest canes and thin the rest. Prune these spring flowering shrubs soon after they have bloomed. Top prune the plant to improve the shape and reduce its size but, be careful not to remove more than 30% of the top growth. Some summer pruning can also be done on particularly vigorous plants but, not after mid-July. As the plant matures, some “renewal pruning” should be done. 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.
Jun 03, For lilacs that bloomed in May, for example, early June is an ideal time to trim. The new wood created after spring is where some of next year's flower buds form. If all the trimming happens in spring, the bush still has plenty of time to grow and produce the wood that will fuel next year's flowers.
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. Jul 26, Lilacs are not toxic. But you would want to discourage critters from eating lilac wood because it will cut back the flowers. Can you prune a dwarf lilac bush in October?