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Are Your Canna Lily Leaves Turning Brown? [5 Causes With Fixes]

If your Canna Lily leaves turn brown at the end of every growing season, do not worry! Leaves turning brown is their way of saying winter is here.

Canna Lily leaves turning brown indicates the start of dormancy in fall and winter, rust fungus or pest infestation, and care mishaps like poor watering and fertilization. Other than natural causes, immediately diagnose and treat the plant accordingly.

The Canna Lily plant can be revived with proper identification of the causative agent and prompt treatment.

Thus, read on till the end to figure out why Canna Lily’s leaves turn brown with respective solutions.

Why Are My Canna Lily Leaves Turning Brown [Causes & Fixes]

Canna Lily proliferates profusely during Spring and Summer under warm temperatures up to 90°F, full sun, and humid air.

When the plants’ care needs are poorly met or compromised with fungal diseases, Canna Lily leaves start turning brown as a cry for help.

So, let us delve deeper into each core reason behind Canna Leaves turning brown and the respective solution.

1. Canna Lily Rust Disease

Leaving the Canna Lily leaves wet for too long is the main reason behind the rust development in the plant.

At first, the rust infection causes orange spots which spread over the Canna leaves, making them turn brown and eventually causing immature leaf drops.

The infection often appears on Canna Lily plants around the beginning of the fall.

So, if your plant is compromised with it, prune off the infected leaves or stems to prevent further escalation of the fungus.

canna lily leaves turning brown from edges
Rust fungus is one of the most common reasons why the Canna Lily leaves turn brown.

Apart from snipping, you can resort to fungicides with mancozeb or copper when the condition is severe.

Remember, when the leaves are left untreated, it can significantly slow growth and even make the plant unsalvagable.

Additionally, abstain from watering Canna Lily from the top to avoid making leaves wet. You can directly pour water into the plant base using a hose pipe.

2. Arrival of Winter

Canna Lily can tolerate temperatures up to 90°F but is highly sensitive to colder temperatures and frosts.

Thus, the plant remains dormant throughout the cold, chilly fall and winter times of the year.

Furthermore, Canna Lily leaves naturally begin turning brown from the edges and gradually spread over the leaves and stems as a sign of the start of dormancy.

In such a scenario, do not panic, as the plant will bounce back with new green leaves in the following Spring.

Moreover, allow your Canna Lily to experience the first fall frost and wait for the stem to turn brown.

If the lowest temperature in winter does not dip below 40°F, aim to cut back the stem 5 inches from the ground. And as winter protection, add a thick layer of mulch.

However, you should consider digging up the Canna Lily rhizomes and storing them in a cool, dark place with subtle moisture.

3. Too Much or Too Little Water

If your Canna Lily plant has leaves turning brown amidst the active growing season, it could be because of poor watering habits.

The hot summer days can dehydrate the Canna Lily plant much faster and cause brown leaves with dry, cracked soil.

Meanwhile, excess water can trigger root rot and other fungal diseases, leading to brown leaves with soggy, mushy, moldy soil.

Generally, during the active season, watering Canna Lily once or twice a week is sufficient.

That said, a flexible watering routine that adapts to the varying water needs of the Canna Lily with temperature is much more ideal.

Remember, Canna Lily in a pot drains much faster than on the ground and requires more frequent watering.

Thus, perform a soil moisture test and ensure the top 1-2 inches of soil is dry before fetching water.

4. Improper Fertilization

Canna Lily plants are heavy feeders and demand once-a-month fertilization to tame their hunger during the active season.

However, too much fertilizer can cause chemical burns and choke the roots of Canna Lily, leading to leaves turning brown.

Furthermore, excess fertilizer causes white salt buildup in the soil, which clogs the soil and hampers drainage.

In such peril, leach out the salt buildup via thorough watering, and if the burn is severe, repot or transplant the plant.

Contrarily, no fertilization invites nitrogen deficiency, resulting in stunted growth with sudden browning and dropping of all leaves.

Thus, aim for slow-release fertilizer or compost every six to eight weeks to keep Canna Lily happy.

5. Troubled By Pests

Infestation of pests like spider mites, thrips, aphids, and caterpillars can also result in Canna Lily leaves turning brown.

The sap-sucking insects feast on the nutrients from the leaves and leave behind brown spots.

Furthermore, the chewers like snails, caterpillars, and slugs eat away the leaves causing remnant parts to turn brown.

canna lily leaves turn brown
Nitrogen-deficient Canna Lily will exhibit sudden leaves browning, immature leaf drop, and stunted growth as a telltale sign.

If the pest invasion is not severe, manually pick or snip off the infected parts of the plant and apply neem oil.

However, when the infestation is severe, use chemical insecticides and pesticides to control the pests.

Pro Tip: Place sticky traps around the plant, regularly use neem oil and clean leaves using a soapy water solution  to deter pests from the plant.

How to Prevent Canna Lily Leaves Turning Brown?

If not for natural causes, following proper care guidelines can prevent Canna Lily leaves from turning brown.

  • For potted Canna Lily, aim for a bottom watering approach and water ground ones directly at the plant base without wetting leaves in the morning.
  • Abstain from misting the plants in the evening or night hours.
  • Ensure the plant receives full sun by placing them in a south window.
  • Below USDA 8-10 zones, dig out the rhizomes in the fall and store them indoors to replant them in the following Spring.
  • Incorporate a soil moisture meter or poke chopsticks to check soil moisture before watering.
  • Refrain from sticking with complex and fast watering rules, as the watering needs vary per other environmental parameters.
  • Try sterilized organic fertilizers, as they do not cause chemical burns or salt buildup.
  • Keep the plants’ leaves clean, and do not expose them to high humidity for too long.
  • Always use sterilized pruners to snip off the browning leaves.

The leaves that have turned brown can not be revived or returned to their original green form. Thus, snip them off when you notice them on the plant.

Editors Note

Immediate Snip Off Ensures No Escalation!

When the fungal disease is the culprit behind Canna Lily’s leaves turning brown, immediately snip the brown parts to control and prevent further spread.

But if a fungus is not the reason behind browning and the leaf’s edges are the only brown part, let them be as they still serve their purpose.

All The Best!