Cause No. 1: Too warm overwintering
Dendrobium orchids need an alternating warm climate for their flower induction. While they like to linger in the bright, warm window seat in summer, this does not apply to the winter rest period. The required temperature reduction depends on the respective type. How to do it right:
- Dendrobium phalaenopsis: in summer 20 to 28 degrees Celsius - in winter 12 to 18 degrees Celsius
- Dendrobium nobile: in summer 15 to 28 degrees Celsius - in winter 5 to 13 degrees Celsius
also read
- What to do if a Cambria orchid does not bloom?
- How to Properly Prune a Dendrobium Orchid
- Why doesn't the Cymbidium orchid bloom?
As a rule of thumb, lowering the temperature by 5 to 6 degrees Celsius is necessary for your Dendrobium to flower again. This goes hand in hand with watering the orchid in sips from October until the first buds develop.
Cause No. 2: Root rot as a result of waterlogging
In the care of orchids, the water requirement is often incorrectly estimated. Hobby gardeners mistakenly conclude from their tropical origins that the rainforest flowers should be watered regularly. In fact, the substrate with the aerial roots should only be kept slightly moist and should in the meantime almost dry out.
Too intensive watering causes waterlogging and root rot on Dendrobium. As a result, the root strands soften and the water and nutrient supply cease. The orchid sees no prospect of successful reproduction, so it refuses to flower.
By removing the affected orchid immediately repot in dry pine bark substrate, the problem can be resolved. Take this opportunity to cut out any rotten, soft roots. Then wait 8 to 10 days before watering the next time.
Tips
If you cut off green bulbs, leaves and aerial roots from your dendrobium, you shouldn't be surprised if the orchid doesn't bloom. As long as the plant parts are green and vital, they fulfill important tasks for growth and willingness to flower. cut off is only allowed if they are completely drawn in and dead.