Getting it to bloom
Why won't my Longcluster Japanese Wisteria bloom? (and how to make it flower)
Also called Longcluster Japanese Wisteria, Multijuga Wisteria, Kyushaku Wisteria (Wisteria floribunda 'Multijuga').
More about longcluster japanese wisteria
About Longcluster Japanese Wisteria
Wisteria floribunda 'Multijuga' · also called Longcluster Japanese Wisteria, Multijuga Wisteria · flowering
Arguably the most spectacular of all wisterias, 'Multijuga' produces extraordinarily long fragrant racemes — up to 1 m or more — of light lilac-blue flowers in late spring. An RHS Award of Garden Merit holder, it is a long-lived, vigorous deciduous climber suited to large pergolas, tall walls, and mature trees. Fully hardy to H6, it thrives in sun with biannual pruning.
Plant type: flowering
Watch for — Failure to flower: The most common complaint, often affecting young plants (wisteria may take 7–10 years from seed to flower; grafted plants bloom in 3–5 years). Also caused by too much shade, excessive nitrogen, or incorrect pruning. Prune twice a year: cut summer growth back to 5–6 buds in July–August, then back again to 2–3 buds in late winter.
The reasons longcluster japanese wisteria isn't blooming
Almost every non-blooming longcluster japanese wisteria traces back to one of these, roughly in order of how common they are:
- Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
- Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
- The plant has not been deadheaded, so it stops flowering once it sets seed.
- Irregular watering — drought or waterlogging at the budding stage makes buds abort.
- It is still too young or was checked by a transplant and is rebuilding before flowering.
Feeding longcluster japanese wisteria a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.
The fix — how to get longcluster japanese wisteria to flower
- Maximise sun. Give longcluster japanese wisteria the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
- Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
- Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
- Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.
Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for longcluster japanese wisteria and get the feeding right with the longcluster japanese wisteria fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.
Bloom season and what to expect
Longcluster Japanese Wisteria flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.
Post-bloom care so it flowers again
Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.
For everything else this plant needs day to day, see the full longcluster japanese wisteria care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.
Longcluster Japanese Wisteria blooming — frequently asked questions
Why won't my longcluster japanese wisteria flower?
Longcluster Japanese Wisteria blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
How do I make longcluster japanese wisteria bloom?
Give longcluster japanese wisteria the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
When does longcluster japanese wisteria normally bloom?
Longcluster Japanese Wisteria flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.
What should I do with longcluster japanese wisteria after it flowers?
Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.
What is the single biggest mistake stopping longcluster japanese wisteria flowering?
Feeding longcluster japanese wisteria a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.
Keep reading
- Longcluster Japanese Wisteria care — the full brief (light, water, humidity, problems, pet safety)
- Longcluster Japanese Wisteria light needs — usually the first thing to fix for flowers
- Longcluster Japanese Wisteria fertilising — the right feed for buds, not just leaves
- Should I water my plant? The simple check
- Why is my plant wilting? Wet vs dry
- Underwatered plant — signs and rehydration
- Why won't my peace lily bloom?
- Why won't my jade plant bloom?
- Why won't my tomato bloom?
- All 3229 bloom guides in the Growli library