Question: why doesn't my lilac pierce?

Good morning, please, I would like to know why my lilac (bought in a vase, with splendid flowering), then transplanted to the ground for 2 years, does not bloom at all, although it looks healthy and is full of leaves.

Lilac: Answer: the lilac flowers

Dear Corina,
the Lillà are shrubs belonging to the genus syringa, a native of Asia and the Middle East; they have been cultivated in European gardens for several decades, and therefore they are often hybrids or cultivars, originated from the first specimens brought to Europe several years ago. They are vigorous and rustic shrubs, and their success in gardens is due to the beautiful panicles of flowers, precisely lilac-colored, which bloom in spring; there are varieties with white, purple or even two-colored flowers, which have the edge of the corollas in a contrasting color. The ease of cultivation has made these deciduous shrubs decidedly widespread, even in road beds. That said, the reasons why flowering plants stop flowering are not many, we can only consider two.
- A flowering shrub that likes to be positioned in full sun, tends to stop flowering when it receives low amounts of direct sunlight; as it also happens for flowering plants, such as hibiscus or geraniums, even the lilacs need at least a few hours of direct sunlight to be able to produce their flowering buds, and so if you have chosen a little area when placing your shrub in the house illuminated, it is likely to stop flowering.
- The flowering plants are not all the same and do not all have a similar development. Every variety of flowering plant produces floral buds at different times of the year; the lilacs begin to produce these buds between late summer and autumn, so if at the end of winter we prune the shrub, we are also removing most of the flowers, which are produced at the apex of the branches. The lilacs are not overdeveloped, so they are usually not pruned, except to remove weak or damaged branches. When these shrubs become very old, they have been dwelling for many years, often they proceed to a drastic autumnal pruning, in order to favor the development of a completely new vegetation, which in the following years will bring many flowers.
Other problems generally do not show lilacs; it could also be that your shrub, having been moved from the pot to the ground, took a couple of years to adapt to the new cultivation conditions, and to widen its root system; in this case it may not be strange that it has stopped flowering, but within a couple of years the development of the root system should stabilize and the plant should start to bloom again. Clear that, a good fertilization, with a slow-release granular fertilizer for flowering shrubs, watering in the event of drought, the treatment of possible animal or fungal parasites, increase the chances of your shrub being well located where you have connected it, and start to bloom.