Lilac sentimentality

“You are the smell of all Summers,

The love of wives and children,

The rec­ol­lec­tion of gar­dens of lit­tle children.”

— Pulitzer Prize win­ning Amer­i­can poet Amy Lowell

Amy Lowell’s love song to lilacs appeals to our sen­ti­men­tal side. But who isn’t sen­ti­men­tal about lilacs? Do they not melt our hearts and fill our mem­o­ries with April’s first bloom and waft­ing sweet aroma? Don’t they make you think about lemon­ade and freshly baked cook­ies on grandma’s porch? For me, lilacs were a con­stant on my child­ishly con­structed May Altar where my friends and I would light can­dles and prac­tice devotions.

I was feel­ing that sen­ti­men­tal­ity when I found two lilac bushes in the gar­den of the home I pur­chased sev­eral years ago. Unfor­tu­nately, this year I am not happy and cer­tainly not feel­ing sen­ti­men­tal about the few scrag­gly blooms one of the bushes has man­aged to pro­duce. Fol­low me on my inves­tiga­tive jour­ney. I am con­fi­dent we will find a way to restore my bushes to their for­mer magnificence.

The first thing I wanted to rule out was dis­ease. I inspected the bushes for leaf dam­age. The dead leaves were con­fined to bro­ken branches and prob­a­bly vic­tims of high wind. Leaf curl was min­i­mal and might be attrib­uted to late frosts. I found no evi­dence of insects although often when leaf dam­age is observed the insect is already gone. Had I found leaf min­ers I would have used Bayer Advanced Tree and , I am fairly con­vinced that the lilacs are not dis­eased. So far, so good.

Research revealed sev­eral things that can pre­vent lilac bushes from flow­er­ing. Lilacs need full sun­light and rel­a­tively dry soil. They do not like to be planted too deep. Too much nitro­gen in the soil will make them put energy into growth rather than repro­duc­tion or flow­er­ing. Rock mulch, par­tic­u­larly with land­scape fab­ric, cre­ates an anaer­o­bic con­di­tion in the root zone and dis­cour­ages flow­er­ing. None of these apply to my lilac bush so I con­tinue the research.

I learned that lilac trees form their buds for the fol­low­ing year in early sum­mer so the best time to prune is right after blooms have wilted and fallen off. This could not be the rea­son for their bloom fail­ure since I have never pruned them. How­ever, fur­ther read­ing revealed that lilac shrubs left to grow and spread with­out prun­ing can reach heights over 20 feet. Accord­ing to OSU Exten­sion, the lower branches will likely be bare and the blooms will be out of sight and reach. Bingo! This is exactly my problem.

Now I know I must focus on the proper method of prun­ing. Even though lilacs bloom on pre­vi­ous season’s wood, with­out prun­ing we end up with a woody, unat­trac­tive plant that doesn’t pro­duce a nice spring bloom show. This is my tree! Ide­ally, a lilac bush needs a mix of young new shoots and older stems. The newer stems won’t bloom for sev­eral years, but to keep the lilac bush bloom­ing, young shoots are essential.

Large old branches need to be sys­tem­at­i­cally removed. A rule of thumb is to remove a branch all the way to the ground when it is more than two inches in diam­e­ter. Reg­u­lar annual prun­ing will main­tain lilac bushes at an ideal height of around eight feet.

In order to keep your lilac bush devel­op­ing new stems while the older stems are bloom­ing remove about one third of the branches every year. The bush may be shaped as you are prun­ing. For more infor­ma­tion, visit tinyurl.com/83bze5b.

If you would like to take a cut­ting from your grandmother’s bush you should know that lilacs are not eas­ily prop­a­gated so tim­ing is crit­i­cal. Soft­wood cut­tings before the leaves mature work best. Place these 8 to 10 inch cut­tings in a sand or ver­mi­culite medium with a root hor­mone. Be patient as lilacs grow slowly — only a foot to a foot and a half per year. If you are less patient con­sider mov­ing the entire bush (with grandma’s per­mis­sion, of course!). Care­fully dig up a 36-inch root­ball in early spring when the plant is dor­mant. The next best time is in the fall after the leaves have dropped.

Thanks for accom­pa­ny­ing me on this stroll down mem­ory lane. Wish me luck as I embark on my prun­ing adven­ture. I hope to one day soon see (and smell) my lilacs restored to their for­mer beauty.

Michele Pear­son is an OSU Exten­sion Mas­ter Gar­dener volunteer.

Posted by Master Gardener on Apr 27 2012. You can follow any responses to this entry through the RSS Feed. Comments can be made below.