Whether you are training, maintaining, or rejuvenating your shrub, these guidelines will yield the best results
The intoxicating bouquet of a lilac in full bloom stir up acute memories for most gardeners . One puff of air place me back to Lilac Sunday preparations at the Arnold Arboretum in Boston , where I once lose control of my push lawn mower on a outrageous hill and find out in horror as the whirling sword wobble into a treasured specimen . But lilac are very resilient ; it accept just a few skilled pruning cut to restore the shrub ’s visual aspect .
| At a glance |
Lilac |Syringaspp. and cvs.
Zones:3–8
Conditions : Full sun ; plenteous , moist , well - debilitate grunge
Habit : Multistemmed and broadly vase - forge , with mark emerge from the underground root systems .
item-by-item plants will produce together into a dense brushwood when planted as a hedgerow .
Popular Varieties :
Common lilac(Syringa vulgarisand cvs . , picture ) has cultivars that bloom in subtlety of lavender , periwinkle , deep boo , pink , and white . Some glamourous cross even have striped or two-fold prime .
Korean lilac(Syringa meyeriand cvs . ) is a compact , well - acquit full cousin of the common lilac . Its cultivar have diminutive parting with wavy edges and touchy , pale , pinkish - lavender to white rosiness . Its thickset habit makes it ideally suited for exercise as a innate low-pitched hedge .
The Bloomerang ® series(Syringa× curriculum vitae . ) are dwarf cultivar that are hybrid of four different specie .
Their first bloom is in spring , as expect , with a rebloom in late summer .
Fortunately , lilac pruning is almost never this striking . These multi - cauline shrub all gain from regular upkeep , and most will even respond well to heavy pruning when need . A critical eye and a series of well - planned cut will make a swelled difference in the flora ’s appearance and performance , whether you are training a new plant life , maintaining an constituted specimen , or rejuvenate an overgrown shrub that has not been touched in years .
irrespective of the species or the time of year , there are a few preliminary steps that will aid you to approach any pruning occupation with confidence .
ill-treat 1|Assess the situation . begin any pruning project by taking the tenacious view , abuse back about 20 feet to measure your subject . Be curious . Is this plant thriving or sputter ? Is it block windows or crowding neighboring tree ?
Step 2|Set goals . Reimagine your lilac base on your initial assessment . Will you be changing the bush ’s shape ? Is this a unseasoned shrub that needs preparation , an established plant in need of mundane maintenance , or an previous specimen with long , list stems ?
Step 3|Remove bushed woodwind . Before you trim down a undivided living branch , identify and remove all in and unkept ones throughout the plant . cut back each dead offset back to a limb choker or to the ground .
Once the dead Natalie Wood is gone , it ’s meter to decide whether the plant needs breeding , routine criminal maintenance , or a arduous restoration . To help you decide , I ’ve get over each of these three pruning strategies on the come Thomas Nelson Page .
1. Use just a few strategic cuts when establishing a new lilac.
All woody plants need some training at planting clock time or in brief thereafter , and all types of lilac are no exclusion . Limit the identification number of live branch you are removing to about 15 % of the shrub ’s overall mickle . This is because young transplants ask most of their vigor reserves to get prove , so it ’s important not to take too much . Focus your campaign on removing dead branch and stem that will never contribute to the trust shape of the lilac . When you try out stems as they come out from the earth , you ’ll see that some are already growing too close to each other or may be twisted together . These event will only become more problematic over time . Ask yourself which branches will make a better donation to the foresighted - term born habit of your lilac .
After every few cuts , mistreat back to secure that you are quell within your pruning limit and that you are balancing the tightness of the canopy . There should be some airwave circulation within the plant without it looking too sparse . The final step is shaping ; produce a bush that is consistent but not a gumdrop . When you take the air off , you desire to see a transformed , more svelte lilac .
2.Routine maintenance combats leggy growth
For lilacs about five old age of age and older , workaday regenerative pruning with a long - term mindset prevents plants from recrudesce an awkward , gangly substance abuse . As lilacs historic period , lower side branch at the base of the plant life will often break off as they become shaded by taller theme . Without these low branch , it looks like the lilac has long , bare “ pegleg ” ( see picture below ) . Legginess also happen when nurseryman habitually remove all of the raw suckering stems , retaining only elderly ones .
Regenerative pruning rejuvenate a works gradually by remove a few of the old main base each year . necessitate yourself which grandiloquent stems could be taken out to countenance sun to filter down into the base of the bush without leave a gape trap . burn these chosen limb down to primer level . rivet on removing one stem at a metre , and maltreat back from the industrial plant to reassess after each excision . Leave most of the soft touch to grow ; this unexampled generation of stems will finally exchange future retirees .
Your final task will be to fine - tune the shrub ’s shape , emphasizing its natural , generally vaselike drug abuse by removing errant or overextended branches . Again , remember to periodically step back and reassess your pruning occupation ; this will help oneself you gauge when it ’s time to kibosh and move on .
Regenerative pruning prioritize recollective - term structural wholeness over maximum prime output . Do not forgo delinquent maintenance pruning because it is the wrong time of year . you’re able to do regenerative pruning on a lilac in early spring , early summer , or early fall . Although your judicious selections will move out some flower buds , you will for sure not eliminate all of them . Making rejuvenation cuts part of your annual routine will encourage a full , lush habit where several generation of growth fly high together .
TIP : Remove large limb in pieces . Taking off the ends of an older branch in a couple of steps will allow you to tease the piece out of the shrub without damaging neighboring stems .
3.In extreme cases, deeper cuts may be necessary
When a common lilac has been subjected to twelvemonth of deferred maintenance , intimately every stem may be larger in diameter , and most of the flowers and foliage will be condense at the close of the upper offset . In a case like this , a hard reset may be appropriate . This is usually not necessary with other lilac specie .
Renewal pruning , or full greening , involves bring down every large , old base to the ground . You may not have as many flowers for a few years as the shrub regrow , but the healthy new base that emerge will put future flowers close to eye ( and olfactory organ ) level .
As you consider rejuvenation on an quondam lilac , you must first count timing and its overall wellness . If it is betimes in the growing season and the shrub is healthy and vigorous , go for it . But be aware that lilacs that are in decline may not hold out refurbishment , peculiarly if you make the cut after summer solstice .
Plan from a distance. Stepping back will help you to evaluate the shrub’s habit as a whole and to imagine how it would look without the branches you plan to remove. If you step back and reevaluate your progress after every few cuts, it will help you decide when to stop, and you’ll be happier with the end result.
I ’d be uncoerced to look that most of our doting lilac memories are from plant that were quite previous at the time . Pruning young lilac shrub too soon and revisiting their pruning needs throughout the geezerhood will greatly contribute to longevity and multigenerational maturation . I ’ve care for many shapely specimens that are over 100 twelvemonth old and still flower attractively .
Jen Kettell is a consulting tree surgeon and the owner of Radiant Leaf Consulting , a firm based in Natick , Massachusetts , that provides training to immature - industry professionals and homeowners .
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Plan from a distance. Stepping back will help you to evaluate the shrub’s habit as a whole and to imagine how it would look without the branches you plan to remove. If you step back and reevaluate your progress after every few cuts, it will help you decide when to stop, and you’ll be happier with the end result.
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Remember the one-third rule when shortening a stem. Make the cut at a junction where the remaining branch is at least one-third the width of the piece you are removing. As always, leave the branch collar intact to facilitate healing (see illustration, above).
For Korean lilacs, you will cut less. The number of branches you remove from a dwarf variety will be smaller because their compact nature inhibits the development of long, leggy stems. However, dwarf Korean lilac cultivars are prone to sending up vertical shoots, also called “water sprouts,” in midsummer, so set aside time to remove some of these.
If a lilac is “all legs,” it’s time to encourage new growth. Removing a few of the oldest stems each year would be a gentle way to encourage the plant to push new growth from the base. Or, if there are at least a few healthy young stems present, cutting back all of the old growth may be an option.
