How Come My Canna Lily Will Not Flower?

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Canna lilies are tender perennials in USD zones 7-10. Perhaps the single most frustrating aspect of having a garden is when orange flowers fail to bloom.

In the case of many ornamentals, this isn’t so much of a problem because they’re mainly grown for foliage.

Blooming Canna lilies - Contemporary Hotel Walt Disney World, Orlando FloridaPin

However, cannas and similar plants are grown almost exclusively for the blooms.

Being native to the Caribbean and South America, cannas prefer a location with lots of sunshine and fertile, moist soil, along with a thin layer of mulch around to help retain moisture.

Before you get fed up and toss all of your reluctant cannas in the compost pile, take a moment to find out why they’re not blooming and how you can remedy the situation.

How Come My Canna Lily Does Not Flower?

There are three categories of problems that can prevent your cannas from blooming:

  • Environmental issues
  • Illness
  • Improper care.

Let’s take a moment to go through the major issues and how you can remedy or even prevent them.


Infestations may not stop your cannas from blooming, but pests are often vectors for disease. The flowers attract pollinators, and hummingbirds especially love the bright red ones. 

Two diseases known for preventing blooms are the following:

  • Canna yellow mottle virus (CaYMV)
  • Canna yellow streak virus (CaYSV).

As these are virii, there’s no cure or treatment, leading to the worst-case scenario of having to destroy your cannas and sterilize the ground they were growing in.

Root rot is another leading cause of bloom failure, which brings us to the next issue:

Improper Watering

Too much or too little water can lead to all sorts of issues, including a failure to bloom.

Cannas exposed to drought conditions will become stressed and may fail to bloom.

Likewise, too much water leads to root rot, a deadly disease that prevents plants from absorbing food and water.

This is easily solved using the soak-and-dry method instead of a schedule.

This method is incredibly easy and involves poking your finger into the soil.

Follow these steps:

  • Water the plant if it feels dry, about 1″ to 2″ inches down.
  • Pour slowly and liberally, working your way around the canna while avoiding the foliage.

When the soil can no longer absorb as fast as you pour or see seepage from a container’s drainage holes, it’s time to stop watering.

Lack Of Pruning

Pruning your perennial cannas is important to their growth the following year, although it isn’t necessary with annuals. 

After the first frost hits, cannas will begin to die back.

Cut it back to around 6” inches from the ground at this time.

Not only does this help prevent pests and disease, but it also causes the canna to store its resources rather than continue investing them in dying foliage.

These resources can then be used the following spring to boost early growth.

Other than deadheading, there is no need to prune unless you think the foliage looks trashy.


Canna lilies are not true bulbs and instead grow from rhizomes, modified stems that store nutrients and shoot up stems.

When you see yellow-streaked leaves or contorted growth, dispose of the plant and any nearby because nothing can be done to cure the viruses. 

Plants need food to grow, and certain nutrients will affect different aspects of the plant’s development.

You’re likely using a balanced fertilizer (such as 10-10-10), but consider switching to a higher phosphorus recipe when blooming time approaches.

Nitrogen is used primarily for foliage growth, while phosphorous encourages flowering.

Thus, a good “bloom time food” will have an NPK closer to 5-10-5 (or 15-30-15 if you fertilize seasonally instead of monthly).


Canna lilies like a balance between company and personal space.

As a result, a bit of root binding or overcrowding will benefit your canna until it passes a certain point.

Once it becomes too overcrowded, individual cannas will compete for resources, causing the entire clump to suffer.

This is remedied by repotting and dividing your canna lilies every 2 to 3 years.

Spacing your cannas at least 1’ foot away from other plants in the garden can also help minimize the risk of overcrowding.

Planting Depth

This rather basic cause can be an easy mistake to make.

The bulbs should be planted no deeper than 2” to 3” inches deep.

Planting deeper than that will stunt the canna’s growth, which leads to delayed or failed bloom cycles.

Poor Lighting

Plant the canna lily rhizomes in late spring or early summer. Position each one 1 to 4 inches deep with the growth sprouts,

Your cannas need at least 6 hours of full sun per day to thrive. If you live in a cool climate, you can start your rhizomes indoors 4-6 weeks before the last frost.  

Too much shade may result in the plant not having enough energy to produce blooms. Any cannas grown in lower zones will need to be dug up and overwintered or grown inside. 

This helps to prevent rot and absorb moisture. Store the rhizomes in a dry location that won’t drop below 40°

If you’re seeing other symptoms of inadequate lighting, such as darkened green leaves, be sure to move the cannas into more direct light or prune back any plants blocking access to the sun.

Poor Soil

Finally, we get to one issue that can be caused by some of the previous problems we’ve discussed: poor soil conditions.

This may involve the following:

  • compacted soil
  • poor drainage
  • lack of nutrients

Compacted soil can have similar effects as overcrowding, with the plant’s roots becoming unable to expand or draw resources from the soil around them.

Remedy this problem by replacing your potting mix every time you divide and working amendments into the soil for garden-based plants.

Some good options for organic soil amendments are peat or sphagnum moss (peat adds acidity while sphagnum is more alkaline), orchid bark, and worm castings.

Meanwhile, examples of good aggregates are the following:

  • Coarse sand
  • Perlite
  • Vermiculite

Aggregates prevent the soil from compacting, aid in drainage, and may also help retain a small reservoir of water, depending on the material used.

Meanwhile, organic components improve soil nutrition, augment fertilizers, and encourage beneficial microorganisms.

You can plant canna lilies just about anywhere in your garden. Mix them with other annual flowers, or create an entire bed just dedicated to them.

In both cases, the resulting improvements to soil quality will help encourage your cannas to bloom.

Common Pests and Plant Diseases 

Pest problems can include leaf rollers and caterpillars, while slugs and snails may munch on the leaves. 

To keep canna lily blooming all season, make sure the plant has full sun, as well as a spring feeding of 5-10-5 fertilizer. 

For the amount, follow the product label instructions. Give them plenty of water weekly and deadhead the blooms as they begin to fade, thus encouraging more growth.

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