Fails to Bloom
Some plants of course take years to mature and produce blooms, but typically we should expect our flowering plants to bloom in the first year or two. And we certainly do not expect them to suddenly stop blooming.
Plants may stop flowering when they have flowered beautifully in the past for a number of reasons. The first thing you need to analyze is changes in the growing conditions.
Was a lovely early spring cut short by harsh winds, freezing temperatures and even late snow? It is not uncommon for early developing flower buds to be killed by a surprise return of winter in the North and Midwest.
Was the previous winter sufficiently harsh with extreme low temperatures? Your plant may not have been hardy enough to resist damage but will likely bloom after a more reasonable winter.
Did intense heat too early in the spring stress your plants? As conditions normalize perennials and annuals will generally recover and bloom later. Many spring flowering woody plants may not flower again until next season.
Are you more attentive to your landscape this year and over fertilizing? This can cause foliage growth at the expense of flowering especially if you have been applying a very high nitrogen fertilizer.
Did you prune your flowering shrub at the wrong time and prune off developing buds?
Are you unusually busy and failing to provide proper feeding and watering?
Have once young trees now grown large enough to cast too much shade on plants that require full sun?
Was a tree taken down that used to cast cooling afternoon shade on plants that prefer morning sun?
Have you installed yard lights that confuse short day plants? Mums for example need long nights with no light, including artificial light, to bloom.
Some of these situations of course you can correct. Trees can be pruned, plants can be moved, and you can try to pay proper attention to feeding and watering. Of course Mother Nature wins nearly every time.