The attached photo of this Forsythia plant is 12 years old. Since planting it has bloomed with the exception of this year. What can I do to promote blooming? Should I cut it down and replant cuttings?
I look forward to hearing from you. Thank you.
Thank you for contacting Toronto Master Gardeners about your forsythia.
There are many reasons why forsythia may not bloom:
- Winter kill / late spring frost – this will affect tender buds that are not winter hardy.
- Improper pruning – flowering occurs on old growth so if pruning was done in the late summer / fall / winter, the flower buds are cut off.
- Lack of sunlight – this plant does best with roughly 6 hours of sunlight.
- Too much nitrogen fertilizer – this will cause vegetative growth at the expense of flowering. This excess food may be from a nearby lawn or other source but can be remedied by adding phosphorus (bone meal) to the soil around the shrub.
- Lack of moisture – if plant didn’t get enough moisture in the late fall, winter and early spring, the plant may be under stress.
- Transplant shock – a new nursery plant or a moved plant can suffer root damage which can lead to stress.
We had a cold spring in Toronto, and the buds might have been damaged. Perhaps, for the first time, you pruned the shrub late in the season last year? Did the shrub get adequate water last fall? The soil around the shrub looks quite compacted, and this can affect soil water holding capacity.
Before resorting to taking cuttings, to rejuvenate the plant, I suggest:
- removing up to one third of the oldest canes as soon as flowering is over.
- adding a layer of compost (2-3 inches) around the shrub. This should loosen up the soil and improve drainage.
- watering the shrub during dry spells.
Hopefully, this will rejuvenate your plant.
If the shrub fails to flower next spring, then you likely need to take cuttings and start to grow a new plant.
Going forward, a yearly trimming of up to one-third of the old canes just after flowering will promote vigor and regular application of compost or green mulch will maintain soil quality.
For more on pruning forsythia, see: