Getting it to bloom

Why won't my Canna 'Red King Humbert' bloom? (and how to make it flower)

Also called Red King Humbert canna, Canna lily, Humbert's canna (Canna 'Red King Humbert').

More about canna 'red king humbert'

About Canna 'Red King Humbert'

Canna 'Red King Humbert' · also called Red King Humbert canna, Canna lily · flowering

Canna 'Red King Humbert' is a classic heritage canna cultivar with dramatic bronze-purple foliage and vivid scarlet-red flowers, creating a bold tropical effect in summer borders and containers. A vigorous, tall grower reaching 1.5-2 m, it has been cultivated since the early 20th century. Mildly toxic to some animals.

Plant type: flowering

The reasons canna 'red king humbert' isn't blooming

Almost every non-blooming canna 'red king humbert' 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 canna 'red king humbert' 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 canna 'red king humbert' to flower

Maximise sun. Give canna 'red king humbert' 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 canna 'red king humbert' and get the feeding right with the canna 'red king humbert' 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

Canna 'Red King Humbert' 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 canna 'red king humbert' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Canna 'Red King Humbert' blooming — frequently asked questions

Why won't my canna 'red king humbert' flower?

Canna 'Red King Humbert' 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 canna 'red king humbert' bloom?

Give canna 'red king humbert' 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 canna 'red king humbert' normally bloom?