Last week I happened to notice a magazine with the heading “Why won’t my wisteria flower?” Well, if you are like me who has had an unforgiving wisteria for years, which just wouldn’t part with a single flower, you will be drawn to the buy the magazine just as a bee is drawn to the pollen on a flower. The magazine I picked up was Gardener’s World and the article was written by Alan Titchmarsh to read it click here. 
Weak wisteria flowers, shown above, I was finally rewarded with two years ago – after approx 8-9 years of patience! I have to say despite them being rather pathetic specimens I was absolutely thrilled to get them. I had given up all hope. My wisteria is the variety sinensis ‘Alba’ – a white fragrant one. The flowers last year were not much better in quality either – I didn’t even bother taking photos.
The article in the magazine suggests considering the location (ok), pruning twice a year (done) but it also suggest something I haven’t done. It suggests a feed with a high potash-rich fertiliser, such as a specialist rose fertilizer. I plan to get some from my local garden centre tomorrow. I am late with this feed. Alan suggests in his article that February is the time to give it – but better late than not at all! It is definitely worth a try, extra watering too. If this year is hot and dry some extra pampering perhaps won’t go amiss.
For more information on care of Wisterias, by the RHS, click here. To see how well my wisteria flowered at the end of May 2007 go to Wisteria from bud to flower .
The photograph, shown above, was taken in my garden on June 4th 2005.
Thank you very much for this bit of information. I have been trying to solve this problem for the last three years since moving to a new garden and inheriting a non-flowering wisteria. Lucky for me that I found your advice in February! I'm off to the shops tomorrow to buy some potash-rich fertiliser. Wish me luck!
Hello. Many thanks for the pointers on growing wisteria. I wondered if you still had a link to the Alan Titchmarsh article on wisteria that you mentioned (I couldn't get the one in your blog to work). I would very much like to read it. I have had some problems with mine since planting it a couple of years ago. Last spring it managed a few of the "weak flowers" you referred to, but then, after looking very healthy, suddenly all the leaves turned yellow and dropped off very prematurely. I was just relieved to see it start to sprout leaves again this year as I had been certain it was dead. No flowers alas (all plants in my neighbourhood – SW France – have been beautifully in flower for weeks), but I feel that if I can just get my plant healthy again this year, there might be hope for flowers next year! The leaves this year have a bit of a yellow tinge (they were definitely green when I first bought the plant), although nowhere near as bad as last year. I have seen others around my neighbourhood with a similar colour and they are in flower. Anyhow, I will for sure try the rose feed (I'm a little late, I know); but it would be great to read the article in full, should you still have access to it. Thank you in advance.