How to Prune a Lilac Bush

Lilac blooms are a great indicator that spring has arrived. Their aromatic presence and soft color make them a beautiful addition to any landscape. Typically, lilacs reach 10 feet high, but they can grow to be 30 feet. Without regular attention to pruning, lilacs can lose their shape and become overly bushy, inviting disease. So, for healthy lilacs, regular pruning is essential.

Things You'll Need

• Clippers
• Ladder

Instructions

Good Shape

1. Wait patiently for the blooms. Pruning at the wrong time of year can kill young buds, which are so small that it's hard to see them coming.

2. Make sure your lilacs have finished blooming. When the flowers have died, it is time to prune.

3. Snip off the dead blooms with clippers, all the way back to the stem. This will keep the bush from seeding and ensure more buds will come next year.

4. Cut small shoots near the ground. These shoots should be sprouting from the main trunk. Also, to keep your lilacs full but not bushy, if you notice that it is crowded in the middle, cut back branches inside the bush. This will help air and sun get to the center and help prevent disease.

5. Trim limbs that seem to be sticking out or that look awkward to you. This will help shape your lilacs. To create a wider lilac bush, cut fewer stems back to main trunk. Keep the tops of your tree rounded; no lilac looks good in a "high and tight."

Getting Too Big

1. Assess the situation. If the lilac bush has outgrown its space or has become unsightly, there is something you can do to get your lilac back to a manageable size. It isn't pretty, and it will take a few years for it to bloom again, but lilacs are hardy and it will recover.

2. Remove all old shoots after a blooming period. Leave just a few new shoots. In a couple of years, the lilac blooms will return.

3. Trim the whole bush way down, about 6 to 8 inches off the ground, in March or early April. During the growing season, you will start to see shoots. The next winter, keep the healthy shoots and cut back the others.

4. Cut back a third of the branches over the course of three years if you can't bear to do it all at once. Choose the oldest stocks and trim down to the soil level by the main trunk. Since it takes about three years for a new shoot to bloom, in three years you'll have new blooms plus continuous blooming throughout the process.

Tips & Warnings

• Avoid trimming with hedge trimmers; the effect will be too boxy for a lilac bush. Instead, use your eye and instinct to help create shape.

Resources

• Lots of helpful information about plant care