This week, we answer, “How can I get my plant to bloom?”

Peony in West Chester, Ohio

It is a common garden question, “Why won’t my plant bloom?” or “Why are my plants no longer blooming?” Our garden experts share their advice on the causes of why your plant is not in bloom.

Why is my Iris not blooming?

  • Overcrowded and need to be divided (maybe every 3-4 years) late July and August
  • Too much nitrogen being fed to them (bulb foods are generally lower in N and higher in P and K or even numbers)
  • Planted too deep
  • Too shady (need ½ or more sun for foliage and tubers)
  • Iris borer/disease problems.
  • Transplant adjustment (re-rooting)

Why is my peony not blooming?

  • Lack of sunlight (need ½ day sun or more)
  • Recovering from transplanting (sometimes take a few years to re-establish and flower)
  • Immature plants
  • Lack of nutrients in the soil
  • Overfeeding with high nitrogen fertilizer
  • Planted too deep (biggest reason)
  • Growing conditions previous year not conducive for flower bud formation
  • Competition with surrounding plants
  • Lack of moisture buds develop but don’t open – frost, disease, drought or too wet.

Why is my lilac not blooming?

  • Late spring freeze /Severe winter temperatures
  • Lack of sunlight (1/2 day or more)
  • Pruning too late in the season (prune within 2-3 weeks after flowers are finished blooming)
  • Insect or disease stressed plant (scale – borers – powdery mildew)
  • Too much old wood and not enough newer – younger growth /Overfeeding of nitrogen
  • Immature plant
  • Transplant shock
  • Summer drought (also too wet)
  • Keep soil pH slightly alkaline
  • Common old fashioned lilacs are known for inconsistent blooming

Why is my wisteria not blooming?

  • Late spring freeze
  • Grown from seed, may take 8-10 years or more before it flowers (look for grafted or named selections which are grown for earlier – consistent flowering)
  • Overfed with nitrogen (do not feed wisteria unless using high P & K fertilizer)
  • Lack of sun (needs ½ day or more)
  • Improper pruning (usually flower better with regular pruning – heavy winter or spring pruning removes buds – encourages vegetative growth)
  • Summer drought.

Why is my Rose of Sharon not blooming?

  • Too much shade (1/2 day sun or more)
  • Buds rot with too much rain or overhead irrigation
  • Buds will drop or not open from being too dry due to drought Insect problems
  • Excessive nitrogen

Why are my daffodils an spring bulbs not blooming?

  • Fed with too much nitrogen (bulb foods are  lower in N and higher in P and K or even numbers)
  • Bulbs are lacking nutrients
  • Plants competing with other plants for water, nutrients, etc.Planted in a too shady area (need ½ day sun)
  • Poor drainage in soils (bulbs rot)
  • Plant foliage cut off too early or tied up
  • Bulbs stressed from transplanting and skip a year of flowering  Bulbs not adjusting to climate planted in
  • Virus, disease or insect problems
  • Growing conditions previous year not conducive for establishing flower buds
  • Becoming too crowded and need to be dug and divided (competition with each other)
  • Sometimes they just won’t flower, period!

Cincinnati Gardening Made Simple. Have a blooming question? Ask our garden experts!