Rhododendron doesn't bloom! Just why?

Rhododendron doesn't bloom! Just why?
  • Lack of light
  • Wrong fertilization
  • Wrong pruning
  • Pests or diseases
  • Plants propagated from seedlings
  • Buds open prematurely

Bloom strike due to lack of light

Even rhododendrons go on blooming strike due to lack of light. When rhododendrons are completely in the shade, they use up all of their energy to form enough leaf surface to use the few rays of the sun. They reduce the bloom formation.

also read

  • Rhododendron brown leaves and spots - what to do?
  • Rhododendron pests - this is how you drive away the killer
  • First select the correct rhododendron location, then plant

What to do? Put the plant in a sunnier location in autumn or provide more light by cutting back and thinning out the treetop.

Wrong fertilization

Too much good food not only makes us humans, but also the rhododendron fat and blooming-lazy. Over-fertilization with nitrogen and phosphorus reduces the abundance of flowers. Both active ingredients activate growth and leaf formation while phosphorus contributes to flower formation.

What to do? Use pure nitrogen fertilizer in organic form if possible (cattle manure (€ 17.80 at Amazon *) or horn shavings) to avoid one-sided fertilization. Adjust nutrients to the soil.

Wrong pruning

Rhododendrons form their flower buds in the previous year. If you cut it back before flowering, you forego the blaze of color for one season. Only late-blooming rhododendron varieties such as Cunninghams White can be cut back in spring.

Pests or diseases

An infestation of the flower buds by rhododendron cicadas in May can destroy the flowers.

What to do? Fight insects with insecticides until the end of May, remove all infected flowers early and dispose of them in household waste.

Seedling Rhododendrons

Propagating rhododendrons from seedlings means waiting years for the first bloom. Vegetatively propagated cuttings or grafts bloom after one or two.

What to do? When buying rhododendrons, look out for refined specimens!

Buds open prematurely

During a warm weather period in winter, the buds open prematurely and freeze to death before they bloom. In any case, the following normal bloom is lost. Diseases can also occur before the buds open.

Tips & Tricks

When you replant or move a rhododendron, it usually does not form any buds. Then it does not bloom the following year. It can also happen that at a young age it occasionally stops flowering or that the supposed flower buds are larger leaf buds.