Help! Why won’t my plant bloom?

We get more questions about why won’t plants bloom.  Here are the reasons why your plants may not be blooming:

IRIS

  • Over crowded 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)

PEONIES

  • 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
  • Over feeding 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.

LILACS

  • 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 /Over feeding 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

WISTERIA

  • 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)
  • Over fed 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.

ROSE OF SHARON (flower buds won’t open)

  • 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

SPRING BULBS (DAFFODILS)

  • 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 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 or diseased 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!