When To Prune Lilacs And General Care Guidelines my1929charmer.com/master-gardening-when-to-prune-lilacs/ With Spring finally peeping her head out I thought it was a good idea to bring back the post on the When To Prune Lilacs. Click here to see How to Prune Shrubs Lilacs are soon to be in bloom and their unmistakeable fragrance will fill the air! I ve updated this post to you can print it out and a PDF version: How To Care For Lilacs 1/5
How to prune and care for Lilacs. Hopefully, this information will help you keep your Lilacs looking their best which will provide great blooms every year. There is only ONE time of the year to prune a Lilac.RIGHT AFTER it blooms! NOT a month later, NOT in summer and NOT in Fall. The only time to prune lilacs is RIGHT AFTER it blooms. Note: Dwarf Lilacs rarely need pruning they do not get out of control. All you need to do is cut off the dead after blooming. Why is that? ****Early blooming shrubs develop their flower buds during the summer and fall of the PREVIOUS year (a.k.a. old or last years wood). It s what is meant by flowering on old wood. Summer and fall flowering shrubs bloom on new wood or stems that grew the same season as flowering. Lilacs belong in the shrub group of early bloomers shrubs are called early flowering shrub. These are shrubs that flower before June 15th (includes lilacs, weigela, spirea, forsythia, viburnum, St. Johns wort, red twig and yellow twig dogwood, deutzia, kerria, mock orange). Pruning should be done immediately after flowering. If you prune this shrub group in winter or early spring (before blooms) it will remove the flower buds and the current season s flowers. Why aren t my lilac blooms as large as they use to be? Why doesn t it bloom anymore? Lilacs require at least 6 hours of full sun. The largest lilac flowers to bloom are on stems that are not more than 5 or 6 years old. As the stems get older, the flowers become fewer and smaller, and more out of reach. But with proper pruning, a lilac can produce flowers reliably for decades. What technique you use depends on the age of your shrub. What are the Pruning Techniques? An annual maintenance routine keeps plants vigorous. Pruning is a good thing promotes new plant growth maintains plant size encourages flowering removes diseased or dead limbs helps control insect and disease problems and relieves cabin fever. There are two methods: 1) Rejuvenation, and 2) Renewal REJUVENATION PRUNING: This method is for lilacs, weigela, spirea, forsythia, viburnum, St. Johns wort, red twig and yellow twig dogwood, deutzia, kerria and mock orange. It is good for those lilacs that have seen better days, it is the complete cutting down of all stems to 4 to 6-inch stubs (hard pruning). It is done when plants like lilacs become too large, 2/5
with too many stems and should be done early in the year. In other words, the shrub is a tangled mess of stems and completely grown out of control and very little flowering. This method is done once every 4-5 years. Please refere to the guideline, When To Prune Lilacs, before you start pruning. You prune back ALL the stems to about 4-5, leaving you nubs. This is often painful on the owner, but it is not painful on the lilac shrub. Your lilac brush will come back like a new baby! RENEWAL PRUNING: Renewal pruning is done over the course of three years, it is less severe and will bring your lilac back to a healthy flowering state (and less shock to the owner). 3/5
1st year: Take 1/3 of your lilacs old wood stalks down to the ground, and trim remaining branches back 2-3 feet 2nd year: Take another 1/3 of old wood stalk down to the ground and after flowering cut back new growth 1-2 feet 3rd year: Do the same thinning process (remove 1/3 of oldest branches) and cut back new growth after blooming. Each year after trimming back new growth after blooming, don t take any stalks down to the ground just reduce height. Use the guide below to show the angle your cuts should be when trimming back the remaining branches. 4/5
Remember: If you do this technique much later (like spring and after) you are cutting off all of next spring s luscious blossoms in the process. Use this guideline, When To Prune Lilacs, before you start pruning. How To Fertilize Lilac Shrubs Bone meal is a great fertilizer for lilac bushes because it makes the soil more alkaline. It is a natural plant food easy for the lilac to intake. Fertilizing lilacs isn t strictly necessary except after the first and second years of planting. If you are planting a new shrub you can fertilize with a superphosphate and limestone to sweeten the soil and avoid excess acidity. Lilacs like alkaline soil. Only bushes planted in poor soil will really benefit from annual feeding. Use an NPK fertilizer 5 (nitrogen)-10 (phosphorus)-10 (potassium) ratio when you do feed the plants. Spread 1 cup granular food evenly around the root zone of the plant and water into the soil. Use refer to the guideline, When To Prune Lilacs, before adding fertilizer. General Lilac Care General Lilac Care For old, poorly cared for plants that have become tangled masses of suckers, prune the bushes after bloom to rejuvenate them. A fertilizer for lilac bushes can be applied in early spring but a better way to reinvigorate these tired old plants is by pruning out 1/3 of the old canes for 3 successive seasons. This will allow fresh growth to emerge while still permitting the blooms to grow. Prune off the spent blooms to make room for the next season s flower buds to grow. Using the guideline, When To Prune Lilacs, will help secure success with your lilacs. /recipe] 5/5