Hi, we planted a JTL in the early summer of 2015.. it had some nice blooms on it at that time. No blooms in 2016 ,or 2017. Ant ideas you can share with us on how to encourage some beautiful blossoms? It seems to be growing nicely otherwise. Much appreciated Charles Michaud Liverpool, NY
Lack of flowering may be due to several factors. While Syringa meyeri 'Palibin' will flower when quite small, many lilacs won't bloom for 4, 5 or more years after planting. Lilacs and most woody plants must grow and mature before they are capable of blooming. Exposure also could be a factor. Lilacs need at least 6 hours of sun to bloom well. Improper pruning is another possibility. Many lilacs bloom on the previous season's growth. The flower buds form during the summer months. Pruning lilacs in fall or late winter could remove much of the blooming wood. There is little that an individual can do to encourage lilacs to bloom. Fertilizing the shrubs encourages vegetative growth, but may actually delay flower formation.
My dwarf Korean lilacs are about 10 years old and getting quite bushy. I am never going to do the 1/3 a year kind of pruning. So can I just cut them way back this fall? If so how far back?
Yes, you can definitely cut back the entire thing for restorative pruning! Early spring is the best time for this, and you can cut down to about 8 or 10 inches from the ground.
This article will give you more information: https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm
My Japanese lilac started out just fine this spring when the leaves started to grow and then....they stopped growing. The leaves are green, but very small. There are many flower buds which appear to be developing, but at a slower rate than my neighbour's tree. The winter here in northern Minnesota was harsh and the spring has been dry. Have been watering the tree to try and encourage leaf growth but to no avail. Is there something else I should be doing?
Certainly a harsh or colder then normal winter can effect the tree; its leaves, flowers and overall health.
This article will refresh you on care.
A professional planted the tree & trimmed some more dead branches from that same sparse side last summer. The tree is in an open area that receives full sun but never really developed on that one side. Should I have it removed or will it eventually start branching out on that sparse side?
You can try pruning it; that should encourage branching.
I was given Japanese beetle trap and wondered if better to put on the neighbour’s Linden tree or my Japanese tree lilac. Suggestions?
Actually it's better not to use the traps. They will bring Japanese beetles from miles around, more than you would have if you didn't use them. It's best to go out in the morning and knock any into a container of soapy water.
Japanese beetles feast on about 400 different plant species. According to Arbor Day, Linden is one of their favorites. I have read that lilacs are not usually bothered.