Table of Contents
- Introduction
- Understanding Cannas: The Basics of These Tropical Stars
- When to Plant Cannas for the Best Results
- Choosing the Perfect Spot in Your Garden
- How to Plant Canna Rhizomes Step-by-Step
- Essential Care for Thriving Cannas
- Deadheading and Pruning: Keep the Blooms Coming
- Growing Cannas in Containers
- Overwintering: Saving Your Cannas for Next Year
- Common Challenges and Easy Wins
- Conclusion
- FAQ
Introduction
Nothing says summer quite like the bold, architectural foliage and vibrant blooms of cannas. These plants are the ultimate garden showstoppers, bringing a lush, tropical feel to any backyard, regardless of where you live. At Longfield Gardens, we love cannas because they are remarkably resilient and offer a massive visual reward for a relatively small amount of effort. Whether you have a sprawling garden bed or a sunny balcony with space for a few pots, these "horticultural titans" are ready to perform. For an easy shopping starting point, browse our Assorted Cannas.
In this guide, we will walk you through everything you need to know about canna how to grow, from selecting the perfect sunny spot to the simple steps of planting and seasonal care. We’ve designed this for everyone from the busy beginner to the seasoned gardener looking for a summer refresh. By focusing on a few gardening basics, you can enjoy these towering beauties from midsummer right through to the first frost.
Growing cannas is a straightforward and rewarding way to add dramatic height, stunning color, and a touch of the tropics to your outdoor living space.
Understanding Cannas: The Basics of These Tropical Stars
Before we dig into the soil, it helps to understand what makes a canna unique. While many people refer to them as "canna lilies," they are not true lilies at all. They are actually more closely related to ginger and bananas. This relationship is obvious when you look at their large, paddle-shaped leaves that catch the breeze and the light. If you want to compare plant heights and habits, take a look at Tall Cannas.
What is a Rhizome?
Cannas grow from rhizomes. A rhizome is a thick, fleshy underground stem that stores energy for the plant. You might see them sold in bags of peat moss or wood shavings. When you look at a canna rhizome, you will notice small bumps or points; these are called "eyes," and they are the spots where new growth will emerge.
One of the best things about rhizomes is how hardy they are. They contain all the "fuel" the plant needs to get started. Even if you aren't sure which way is up when you plant them, the plant is smart enough to send its shoots toward the warmth of the sun and its roots down into the earth.
Variety and Versatility
Cannas come in a staggering array of sizes and colors. Some dwarf varieties stay under two feet tall, making them perfect for the front of a border or small containers. Others can reach heights of six to eight feet in a single season, creating a natural privacy screen or a dramatic backdrop for other flowers. For smaller spaces, Short Cannas are a good fit.
The foliage is just as important as the flowers. Depending on the variety we choose, the leaves can be bright green, deep burgundy, bronze, or even variegated with stripes of yellow, white, and orange. The flowers themselves appear in saturated shades of red, orange, yellow, pink, and bicolor patterns.
Key Takeaway: Cannas grow from energy-storing rhizomes and are prized for both their towering, colorful flowers and their massive, banana-like foliage.
When to Plant Cannas for the Best Results
Timing is the most important factor when learning canna how to grow. Because these are tropical plants, they have zero tolerance for frost and do not like cold soil. If you want to match your planting window to your climate, check the Hardiness Zone Map.
The Temperature Rule
The simplest rule of thumb is to wait until you are ready to plant your tomatoes. This usually happens when the danger of frost has passed and the soil temperature has reached a consistent 60°F. If you plant too early in cold, wet soil, the rhizome may sit dormant for a long time or, in the worst-case scenario, begin to rot before it has a chance to sprout.
Starting Indoors for a Head Start
If you live in a northern climate with a short growing season, you can give your cannas a "head start" by planting them in pots indoors about four to six weeks before the last frost date. This allows the rhizome to wake up and begin developing a root system in a controlled, warm environment. When the weather finally warms up, you’ll have a sturdy young plant ready to take off as soon as it hits the garden soil.
What to Do Next:
- Check your local frost dates to determine your planting window.
- Purchase a simple soil thermometer to check the temperature 2 inches deep.
- If starting indoors, place pots in a warm, sunny window or under a grow light.
- Ensure your indoor pots have drainage holes to prevent soggy soil.
Choosing the Perfect Spot in Your Garden
Cannas are not shy; they want to be the center of attention, and that starts with the right environment. Following the "right plant, right place" rule ensures your cannas reach their full potential. For more on matching plants to site conditions, see Garden Basic Essentials.
Sun is Non-Negotiable
To produce those famous vibrant blooms and maintain the rich color of their leaves, cannas need full sun. This means at least six to eight hours of direct, unfiltered sunlight every day. While they can survive in partial shade, they will likely become "leggy," meaning they grow tall and thin as they stretch for the light. Shaded cannas also produce fewer flowers and may lose the dramatic coloring in their foliage.
Soil and Drainage
Cannas are "heavy feeders" and "heavy drinkers." They thrive in soil that is rich in organic matter. Before planting, it is a great idea to mix in some compost or well-rotted manure to provide a steady supply of nutrients.
In terms of moisture, cannas are unique because they love water. They can handle "wet feet" better than almost any other summer bulb. In fact, some varieties are even grown at the edges of ponds. However, they still need soil that is well-draining enough that they aren't sitting in stagnant, airless mud. If your garden has heavy clay, adding compost will help improve the structure and drainage.
Protection from the Wind
Because cannas have such large, soft leaves, they can act like sails in a high wind. Strong gusts can shred the leaves, leaving them looking a bit "ratty" or tattered by mid-summer. If your yard is particularly windy, try to plant your cannas near a fence, a wall, or a sturdy group of shrubs that can act as a windbreak.
How to Plant Canna Rhizomes Step-by-Step
Once the soil is warm and you’ve found the perfect sunny spot, it’s time to get your cannas in the ground.
Step 1: Prepare the Soil
Loosen the soil to a depth of about 10 to 12 inches. This gives the roots plenty of soft earth to grow into. This is the perfect time to mix in a few inches of compost. At Longfield Gardens, we find that taking five extra minutes to prepare the soil leads to much larger plants and more blooms later in the season.
Step 2: Dig the Hole
For most canna varieties, you want to dig a hole that is about 4 to 6 inches deep. If you are planting multiple rhizomes, spacing is key.
- Tall varieties: Space them 2 feet apart.
- Dwarf varieties: Space them 1 foot apart.
Step 3: Position the Rhizome
Place the rhizome in the hole horizontally. Look for the "eyes" or those small growing points. Ideally, these should point upward. If you can't tell which side is which, don't worry—just lay it flat. Cover the rhizome with 2 to 3 inches of soil and firm it down gently with your hands to remove any large air pockets.
Step 4: Water and Wait
Water the area thoroughly immediately after planting. This settles the soil around the rhizome and "wakes up" the plant. After this initial watering, be patient. Cannas can be slow to sprout, sometimes taking three weeks or more to show their first green shoots. Avoid overwatering during this waiting period; the soil should stay moist but not saturated until you see active growth.
Key Takeaway: Plant rhizomes 4-6 inches deep in warm soil (60°F+), ensuring they have enough space to spread their large leaves and strong root systems.
Essential Care for Thriving Cannas
Once your cannas have sprouted and are beginning to climb toward the sun, they require very little maintenance to stay healthy.
Watering for Success
Cannas are thirsty plants. To keep those large leaves lush and prevent the edges from turning brown, they need consistent moisture. During the heat of the summer, you may need to water them every other day, especially if they are in containers. A deep soaking once or twice a week is usually better than a light sprinkling every day. This encourages the roots to grow deeper into the soil, making the plant more stable and drought-resistant.
Feeding Your Plants
Because cannas grow so much biomass in a single season, they need plenty of "fuel." We recommend applying a balanced, slow-release fertilizer at planting time. You can follow this up with a water-soluble fertilizer every few into the growing season to keep the blooms coming. Look for a fertilizer with a slightly higher nitrogen count if you want to maximize the height and foliage of your plants.
Mulching
Applying a 2-inch layer of mulch (like shredded bark or compost) around the base of your cannas is a great way to conserve moisture. It also helps suppress weeds that might compete for nutrients and gives the garden bed a clean, finished look.
Deadheading and Pruning: Keep the Blooms Coming
One common question regarding canna how to grow is whether you need to prune them. While they don't require heavy pruning, a little "grooming" goes a long way.
The Art of Deadheading
Deadheading is the process of removing faded flowers. This prevents the plant from putting energy into producing seeds and instead redirects that energy into creating new flower spikes.
- Look at the flower stalk. You will often see several buds at different stages of development.
- Only snip off the individual spent flower, being careful not to damage the buds that are still waiting to open.
- Once the entire flower spike has finished blooming, you can cut that specific stalk back to the next set of leaves.
Mid-Season Refresh
Sometimes, by late August, the lower leaves of a canna might look a bit tired or sun-scorched. You can simply trim these off near the main stem. This won't hurt the plant and will keep it looking fresh and tropical until the end of the season.
What to Do Next:
- Monitor your plants weekly for spent blooms.
- Use clean, sharp pruners to avoid tearing the stems.
- Check the soil moisture by sticking your finger an inch into the ground; if it feels dry, it's time to water.
- Apply a mid-summer boost of fertilizer to support the late-season flower show.
Growing Cannas in Containers
If you don't have a lot of garden space, or if you want to dress up a patio, cannas are excellent container plants. Their upright growth makes them the perfect "thriller" in a thriller-filler-spiller arrangement. A standout container choice is Canna Tall Tropicanna Gold.
Choosing the Right Pot
Cannas have vigorous root systems, so they need plenty of room. A pot that is at least 15 to 18 inches in diameter is ideal for a single rhizome. Ensure the container has large drainage holes at the bottom.
Potting Mix and Placement
Use a high-quality, well-draining potting mix. Avoid using "topsoil" or "garden soil" in pots, as it is too heavy and can become compacted, which limits root growth. Because pots dry out faster than the ground, you will need to be extra diligent about watering. In the height of summer, a container-grown canna may need water every single day.
Design Tips
Try pairing a bronze-leafed canna with lime-green sweet potato vines or orange lantana. The contrast in colors and textures creates a professional-looking display with very little effort. Since cannas grow tall, place your containers in a spot where they won't be knocked over by strong winds.
Overwintering: Saving Your Cannas for Next Year
In USDA zones 7 or 8 through 11, cannas are typically perennial and can stay in the ground all year. However, for those of us in colder zones, we need to protect those precious rhizomes from the freezing winter temperatures. Before you plan for spring, review the Shipping Information so you know what to expect when your order is on the way.
When to Lift the Rhizomes
Wait for the first light frost of the autumn. This frost will usually turn the canna leaves black or brown. Don't worry—the rhizome underground is still perfectly safe. This is the plant's signal that it's time to go dormant.
The Storage Process
- Cut back the foliage: Use pruners to cut the stems down to about 4 to 6 inches above the ground.
- Dig carefully: Use a garden fork or shovel to lift the clump of rhizomes out of the dirt. Start digging about a foot away from the stem to avoid slicing through the rhizomes.
- Clean and dry: Shake off the excess soil. Let the rhizomes sit in a dry, shaded area (like a garage or shed) for a few days to "cure."
- Pack them away: Store the rhizomes in a box or breathable bag filled with slightly damp peat moss, vermiculite, or sawdust.
- Find a cool spot: Keep the box in a cool, dark place that stays between 40°F and 50°F. A basement or a crawlspace is often perfect.
Check on your stored rhizomes once or twice during the winter. If they look shriveled, give them a light mist of water. If any look soft or rotten, remove them so the rot doesn't spread to the healthy ones.
Common Challenges and Easy Wins
Cannas are generally very healthy, but like any plant, they can occasionally run into a few hiccups. Leading with the right care is the best way to prevent issues. If you ever want reassurance about order quality, our 100% Quality Guarantee explains how Longfield Gardens stands behind its plants.
Pests to Watch For
The most common pest is the canna leaf roller. These are small caterpillars that stitch the leaves together before they unfurl. If you notice a leaf that won't open, you can usually just unroll it and remove the caterpillar by hand. For larger plantings, a simple application of Bacillus thuringiensis (Bt), which is a naturally occurring soil bacterium, can help keep them in check.
Non-Blooming Cannas
If your cannas have plenty of leaves but no flowers, the most likely culprit is a lack of sunlight. Moving them to a sunnier spot next year will usually solve the problem. Another possibility is a lack of nutrients; remember, these are hungry plants that appreciate a good meal of compost or fertilizer.
Realistic Expectations
The size and bloom time of your cannas will depend heavily on your local weather. In a cool, rainy summer, they may grow more slowly than in a hot, humid one. Gardening is a partnership with nature, and some years the "tropical" conditions will be more in your favor than others.
"The secret to massive cannas is simple: give them as much sun as possible and never let the soil dry out completely during the heat of July."
Conclusion
Mastering canna how to grow is one of the most rewarding projects a gardener can take on. These plants offer a scale and drama that few other flowers can match, transforming a standard garden into a lush sanctuary in just a few months. By focusing on warm soil, plenty of sunshine, and consistent water, you are setting yourself up for a spectacular summer show.
At Longfield Gardens, we believe that gardening should be a source of joy and relaxation. Cannas fit this philosophy perfectly because they are tough, easy to care for, and incredibly generous with their beauty. Whether you are planting them for their brilliant flowers or their variegated leaves, they are sure to become a favorite in your summer landscape.
Your Next Steps for Canna Success:
- Choose a mix of heights and foliage colors to create visual interest.
- Wait for the soil to hit 60°F before planting your rhizomes outdoors.
- Keep the water flowing during those hot August weeks.
- Enjoy the hummingbirds and butterflies that will inevitably visit your blooms.
Ready to start your own tropical oasis? We are here to help you choose the perfect varieties to make your garden the envy of the neighborhood. Happy planting!
FAQ
When is the best time to plant canna rhizomes?
You should plant canna rhizomes in the spring once the danger of frost has passed and the soil has warmed to at least 60°F. This usually coincides with the time you would plant tomatoes or other heat-loving vegetables. In colder regions, you can start them in pots indoors 4–6 weeks earlier to extend your growing season.
Do cannas need full sun to bloom?
Yes, cannas perform best when they receive at least 6 to 8 hours of direct sunlight each day. While they can grow in partial shade, they often become leggy, produce fewer flowers, and their foliage colors may not be as vibrant as those grown in full sun.
How often should I water my cannas?
Cannas prefer consistently moist soil and should be watered deeply at least once a week, and more frequently during periods of extreme heat or drought. If you are growing cannas in containers, they may require daily watering because pots dry out much faster than garden beds.
How do I store cannas for the winter in cold climates?
After the first frost kills the foliage, cut the stems back to 4 inches and carefully dig up the rhizomes. Let them dry for a few days in a sheltered spot, then store them in a box with peat moss or sawdust in a cool, frost-free location (40-50°F) until spring.