Cannas, frequently called ‘Canna Lilies’, are tropical plants with brilliant green foliage that can only be described as profuse and plush.
Though seekers of rich green shapely foliage would be enamoured of Cannas, so too would those who prize large flowers – which have curved and curling petals and are frequently found in vibrant shades of the warm spectrum from yellow through red, and are often bi-coloured.
Seeds will be hard to come by because these plants do not grow true from seed, for which reason, plants grown from seeds have unpredictable flowers that are sometimes even more striking.
However, if you have collected seeds from your garden Cannas or obtained them from a friend, you can certainly grow new plants from seed.
“Cannas are good to sow because they are easy, look exotic and you usually get a flower in the first year,” shares Exotic Plant Expert Will Purdom.
I grew Cannas from seed earlier this year and I must say it does have a couple of drawbacks:
But you can do it – we spell out a straightforward process for growing Cannas from seed:
Cannas are spectacular tropical plants known for their lush vibrant foliage and dazzling summer flowers. While cannas are commonly propagated from rhizomes, growing cannas from seeds can be an easy and affordable way to add these beauties to your garden or containers. In this comprehensive guide we’ll walk through every step of successfully planting cannas from seeds.
Why Grow Cannas From Seeds?
Starting cannas from seeds offers several advantages:
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Cost savings – Purchased rhizomes can be pricey, but a packet of seeds is very affordable.
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Wider variety – Seed grown cannas offer many more varieties than what you find as starter rhizomes. From bold foliage to stunning blooms cannas grown from seed provide diverse options.
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Simple process – Cannas germinate readily from seeds with proper treatment. The process is easy enough for beginners.
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Genetic diversity – Plants started from seed have greater genetic diversity versus cloned rhizomes, improving the health and vigor of your cannas.
For best results, follow some simple tips when planting your canna seeds this season.
When to Start Canna Seeds
Cannas require warm conditions to sprout and grow properly. Start canna seeds indoors 6-8 weeks before your last expected spring frost.
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Northern zones – Start seeds in mid February to early March.
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Southern zones – Mid March to early April is ideal.
Heating mats can provide bottom warmth to aid germination. Aim for soil temperatures of 70-85°F.
Preparing Seeds for Optimal Germination
Untreated canna seeds have a tough outer coating that inhibits water absorption and germination. To encourage faster, uniform sprouting, it’s best to prepare seeds before planting.
Recommended seed prep techniques:
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Soak seeds in room temperature water for 12-24 hours. This softens the seed coat.
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Gently scratch or nick seeds with sandpaper or a file. Allows moisture to penetrate.
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Soak seeds in dilute hydrogen peroxide to further soften coats.
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Allow prepped seeds to dry on paper towels before planting to prevent rotting.
How to Plant Canna Seeds
Follow these simple steps for planting prepped canna seeds:
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Fill starter pots or trays with a commercial seed starting mix. Moisten first.
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Sow 2-3 seeds per individual cell or pot, 1/4-1/2 inch deep.
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Lightly cover seeds and mist gently to avoid displacing.
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Cover containers with plastic domes to retain moisture.
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Place in warm location (75-85°F) with bright indirect light.
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Keep soil moist, not saturated, until sprouting. Lift covers for airflow.
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Seeds typically germinate within 1-3 weeks. Acclimate seedlings before transplanting.
Transplanting Canna Seedlings
Once seedlings have 2-4 true leaves, it’s time to move them into the garden after all danger of frost has passed.
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Harden off plants by setting them outside in partial shade for 7-10 days.
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Prepare beds with rich loose soil and compost. Cannas love fertility!
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Space plants 12-18 inches apart in beds or containers. Plant at same level as in pots.
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Water transplants thoroughly and mulch beds to retain moisture.
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Feed with balanced liquid fertilizer every 2-3 weeks once established.
Ongoing Care for Growing Cannas
To keep your cannas thriving all season:
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Site in full sun (minimum 6 hours direct sun per day).
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Water deeply when the top few inches of soil become dry. Established cannas are moderately drought tolerant.
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Stake tall varieties as needed. Pinch back leggy stems to encourage bushy growth.
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Deadhead spent blooms to prolong flowering. Cut back to a leaf node.
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In warm zones (7-10), cannas can remain in the garden over winter. Mulch well after first frost.
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In colder climates, dig up tubers to store dormant over winter. Keep at 45-50°F.
Top Canna Varieties for Seeds
Some stellar cannas to try growing from seed:
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‘Tropicanna’ – Vivid orange blooms on purple-bronze foliage. Grows 3-4 feet tall.
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‘Australia’ – Large scarlet flowers on green leaves. Matures at 5-6 feet tall.
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‘Ra’ – Huge soft pink blooms on burgundy-bronze leaves. 5 feet tall.
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‘Erebus’ – Dark maroon leaves with red flowers. A shorter variety at 4 feet.
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‘Intrigue’ – Yellow speckled foliage with orange blooms. Finishes at 3 feet tall.
Let’s Recap – Planting Cannas from Seeds
Growing cannas from seeds is an easy, affordable way to enjoy these tropical beauties. Follow these steps for success:
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Start seeds indoors 6-8 weeks before your frost-free date.
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Soak and prep seeds before planting to speed germination.
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Sow seeds in warm location (70-85°F) with bright indirect light.
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Transplant seedlings into garden after hardening off and all danger of frost has passed.
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Provide full sun, regular water, and fertile moist soil for thriving growth.
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Deadhead spent flowers and mulch beds over winter in cold climates.
With proper care, cannas grown from seed offer non-stop color in beds and containers from mid-summer into fall. Their huge leaves and dazzling blooms create fabulous focal points in any garden. Give seed propagation a try this season and enjoy a bounty of beautiful, robust cannas!
Scarify The Seeds
Using a carpenter’s hand file or a Swiss Knife file, scarify the seeds by filing their hard coats (the testa) on one side until the underlying white part (endosperm or embryo, depending on which side you are filing from) is clearly visible.
I didn’t actually have much luck using the sandpaper method so I had to place the seeds in a glass of boiling water (yes, they are that tough!).
Scarify about twice as many seeds as you would like to see germinated – about half of mine were too tough, even for boiling water!
Sow The Seeds
Sow germinated seeds such that the emerging white cotyledon and just a bit of the seed is above the soil, and water moderately.
Discard seeds that have not germinated after five days of soaking.
Growing Cannas from Seed! My preferred way!
FAQ
How do you prepare canna lily seeds for planting?
Canna Lily seeds should be soaked prior to planting. Cannas will produce an abundance of seeds that are small black pellets but easy to handle. Canna Lily seeds have a very hard outer shell and should be soaked in water for 12-24 hours in order to improve germination by softening the seed coat.
How long does it take to grow cannas from seed?
Plants started from seed in Winter, will bloom in the same year. If I remember correctly, it takes about 6 months to get a flower. The plant might not reach full size but if you keep the roots over the winter you will get an early crop of lovely flowers in the summer.
How deep should canna seeds be planted?
Sow indoors in March. Plant 1 seed per 12 inch pot or large cell tray 1/4 inch deep in seed starting formula. Keep the soil moist at 70-75 degrees F. Seedlings emerge in 7-14 days.