Plant Doctor Archive

Camellia won't flower

I HAVE a highly fragrant camellia that normally flowers each year, but this year it didn't even bud. I also have an old-fashioned lilac that has been in at least four years and it has never flowered, even though it is in a nice sunny spot with afternoon sun. Both plants are well watered during summer. I was told at the nursery to try potash. What do you think?

IT'S not unknown for lilacs to take a few years to flower after planting, but four years is rather a long time. And for the camellia to previously flower then miss a year is quite unusual.

I asked camellia expert and breeder Neville Haydon for his opinion and he suggests that if the camellia is in reasonable soil and in good health it should be able to look after itself over summer without much extra watering. In normal conditions camellias put on most new growth in the couple of months immediately following flowering. This growth usually stops around mid-summer, matures and sets flower buds in autumn. Neville says extra watering could encourage more than normal late summer and autumn growth, which would probably not be mature enough to set flower buds and it might also inhibit bud set on the earlier growth.

The lilac could be in the same situation. So I recommend you cut out the extra summer watering unless drought conditions are severe. Potash does encourage flowering in most plants, but for the next year or so I would cut out all fertiliser in an attempt to restrict growth and encourage flower bud formation. Good luck. Let us know what happens.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.