Table of Contents
- Introduction
- Understanding the Canna Rhizome
- Finding the Best Spot: Right Plant, Right Place
- Timing Your Planting
- Step-by-Step Planting Guide
- Starting Cannas Indoors for a Head Start
- Choosing the Best Canna Varieties
- Caring for Your Cannas All Summer
- Lifting and Storing for Winter
- Enjoying the Tropical Vibe
- FAQ
Introduction
There is nothing quite like the arrival of the first tropical leaf in a summer garden. Canna lilies bring an immediate sense of lush, exotic beauty to any landscape, regardless of whether you live in a warm southern climate or a cooler northern state. Their bold, paddle-shaped foliage and vibrant blooms are a highlight of the summer season, making them a favorite for gardeners who want to make a big impact with very little stress.
If you are holding your first shipment of canna rhizomes and wondering exactly how they go into the ground, you are in the right place. At Longfield Gardens, we want to make sure your gardening experience is as rewarding and successful as possible. This guide is designed for anyone ready to add these "horticultural titans" to their yard, providing clear steps on orientation, timing, and care.
We will cover exactly how to identify the "up" side of a canna rhizome and provide the foundational steps to ensure they grow tall and healthy. By following a few simple rules about soil temperature and planting depth, you can transform these curious-looking roots into a stunning tropical display.
Understanding the Canna Rhizome
Before we dig into the soil, it helps to understand what you are actually planting. While most people refer to them as canna bulbs for sale, these plants actually grow from rhizomes. A rhizome is a thick, fleshy underground stem that grows horizontally just beneath the soil surface. It acts as a storage unit for the plant, holding all the energy and nutrients needed to send up those massive leaves and bright flowers.
Because a rhizome is a stem rather than a true bulb (like a tulip or daffodil), its growth pattern is a little different. It wants to spread out to the sides as much as it wants to grow up. This is why you will often see several "eyes" or growing points along the length of the rhizome. Each of these eyes has the potential to become a new stalk, which is how cannas eventually form those impressive, dense clumps of foliage.
How to Identify the Top and Bottom
When you look at a canna rhizome, it might look like a bumpy piece of ginger. To figure out which way is up, look for the "eyes." These are small, slightly pointed nubs or bumps on the surface of the rhizome. They may be pink, white, or green, and they look a bit like the eyes on a potato. These are the points where the new stems will emerge.
If your rhizome has already started to sprout, the answer is even easier. Any green or white shoots should point toward the sky. If you see withered, stringy bits hanging from one side, those are the old roots from the previous season, and they should face downward.
What If You Can’t Tell?
Sometimes a rhizome is very smooth or has been trimmed in a way that makes the eyes hard to spot. If you are ever in doubt, the best approach is to plant the rhizome horizontally. Because cannas grow naturally as horizontal stems, planting them flat on their side is a safe and effective method. The plant is smart enough to direct its shoots upward and its roots downward once it feels the warmth of the sun and the moisture of the soil.
Key Takeaway: The Orientation Rule
- Eyes Up: Look for small, pointed nubs and point them toward the sky.
- Roots Down: Any old, stringy fibers should face the bottom of the hole.
- When in Doubt: Lay the rhizome flat on its side (horizontally). The plant will naturally find its way to the surface.
Finding the Best Spot: Right Plant, Right Place
Success with cannas starts with matching the plant’s needs to your garden's conditions. These are tropical plants at heart, which means they have two main requirements: heat and light.
Sunlight Requirements
For the most vibrant flower colors and the healthiest foliage, cannas need full sun. In most regions, this means at least six to eight hours of direct, unfiltered sunlight every day. If you plant them in a spot that is too shady, they may still grow, but they will likely be shorter, produce fewer flowers, and the foliage colors might look a bit dull.
If you live in an extremely hot climate (such as parts of the American Southwest), cannas can benefit from a little afternoon shade to prevent the leaves from scorching. However, for most US gardeners, the more sun you can provide, the better they will perform.
Soil and Drainage
Cannas are famous for their ability to thrive in moist soil, but they still need good drainage. "Drainage" simply means how fast water leaves the soil after a rain or watering. While cannas love water, they do not like to sit in stagnant, "mucky" puddles for long periods, as this can cause the rhizome to rot before it has a chance to grow.
If you have heavy clay soil that stays wet for days, you can improve the spot by mixing in some compost or organic matter. This helps create "fluffier" soil that allows air to reach the roots while still holding onto the moisture the plant needs. If you are planting in containers, always ensure there are holes in the bottom so excess water can escape.
Timing Your Planting
One of the most common reasons a canna might be slow to start is planting it while the soil is still too cold. These are heat-loving plants, and they will sit dormant in the soil until things warm up.
The 60-Degree Rule
We recommend waiting to plant your cannas outdoors until the soil temperature reaches a consistent 60°F. This usually happens a week or two after the last frost of the spring. If the ground is still cold and damp, the rhizome might just sit there, which increases the risk of rot.
A simple way to check is to use a soil thermometer, or simply wait until you are confident that the "jacket weather" is over and the days are feeling truly spring-like. In warmer USDA hardiness zones 8-11, cannas can often stay in the ground year-round, but in zones 7 and colder, they are treated as annuals or lifted and stored for the winter.
Shipping and Arrival
When you order from us, we time our shipping based on your USDA hardiness zone. Our goal is to have your rhizomes arrive about two weeks before the ideal planting time in your area. This gives you a little time to prepare your garden beds or get your pots ready. When your package arrives, open it promptly and check your rhizomes. They should feel firm and heavy for their size.
Step-by-Step Planting Guide
Once the weather is right and you have found the perfect sunny spot, it is time to get your cannas into the ground.
1. Prepare the Hole
Dig a hole that is about 4 to 6 inches deep. If you are planting several cannas together, keep the mature size of the plant in mind. Tall varieties need about 2 feet of space between them to allow for good air circulation and room to spread. Smaller, dwarf varieties can be spaced about 1 foot apart.
2. Place the Rhizome
Place the rhizome in the hole. As we discussed earlier, aim to have the eyes pointing up or lay the rhizome horizontally. Don't worry if it isn't perfectly straight; the plant is very resilient and will adjust its growth as it sprouts.
3. Cover and Firm
Fill the hole back in with soil. Gently pat the soil down with your hands to remove any large air pockets, but do not pack it so hard that it becomes compacted. The soil should feel firm but still breathable.
4. Water Well
Immediately after planting, give the area a good soaking. This "settles" the soil around the rhizome and tells the plant it is time to wake up. After this initial watering, you can hold off on heavy watering until you see the first green shoots peeking through the soil.
What to Do Next: Post-Planting Steps
- Observe: Keep an eye out for sprouts, which usually appear in 2 to 3 weeks.
- Mulch: Add a thin layer of bark or straw to help keep the soil moist and prevent weeds.
- Label: Place a garden marker where you planted the rhizome so you don't accidentally dig it up before it sprouts.
Starting Cannas Indoors for a Head Start
If you live in a northern state with a short growing season, you might feel like summer ends just as your cannas are starting to look their best. To solve this, you can start your cannas indoors 6 to 8 weeks before the last frost date. This gives the plants a "head start" so they are already several inches tall when you move them outside.
Choosing a Pot
Find a container that is large enough to hold the rhizome comfortably with an inch or two of space on all sides. A standard 1-gallon nursery pot is usually a great choice for a single rhizome. Ensure the pot has drainage holes.
Planting and Care
Use a high-quality potting mix (not garden soil) to fill the pot. Plant the rhizome 2 to 3 inches deep. Place the pot in a warm, sunny window or under a grow light. Because indoor air can be dry, check the soil once a week and add water if the top inch feels dry.
Moving Outdoors
Once the outdoor soil has warmed and the danger of frost is completely gone, you can transplant your potted cannas into the garden. Be sure to "harden them off" by placing them outside in a sheltered, shady spot for a few hours a day, gradually increasing their time in the sun over the course of a week. This prevents the leaves from getting "sunburned" by the sudden change in light intensity.
Choosing the Best Canna Varieties
There is a canna for every garden style. Some people grow them specifically for their flowers, while others love the dramatic, multicolored foliage that looks like a stained-glass window when the sun shines through it. In our trial gardens at Longfield Gardens, we evaluate many different types to ensure they perform well for home gardeners.
Tropical Foliage Favorites
- 'Black Knight': This variety is a showstopper with deep, chocolate-burgundy leaves that look almost black. The bright red flowers provide a stunning contrast against the dark foliage.
- 'Tropical Bronze': Featuring warm, copper-toned leaves and scarlet blooms, this variety is perfect for adding a "sunset" feel to your borders.
- 'Stuttgart': Stuttgart is a unique choice for those who love variegation. The leaves are striped with green and creamy white, topped with delicate orange flowers. Note that this variety prefers a bit more shade than others to keep its white stripes from browning.
Compact and Dwarf Varieties
If you have a small yard or want to grow cannas in patio containers, look for Short Cannas.
- 'Orange Punch': This plant stays around 4 feet tall and produces masses of bright orange flowers. It is the perfect height for a large pot on a deck or balcony.
- 'Salmon Pink': A lovely, shorter variety that reaches about 3 feet. The soft pink flowers look beautiful when paired with blue or purple summer perennials.
- 'Madame Butterfly': This smaller variety features classic green foliage and large, salmon-colored blooms that attract hummingbirds all summer long.
Tall Landscape Anchors
If you have a fence line or a back-of-the-border spot that needs height, go for Tall Cannas.
- 'Crimson Beauty': This variety offers traditional green leaves and deep red flowers, often reaching 5 to 6 feet in height.
- 'Miss Oklahoma': Known for its massive, coral-pink blooms and vibrant green foliage, this variety makes a bold statement in any large garden bed.
Caring for Your Cannas All Summer
Once your cannas are established and growing vigorously, they are relatively low-maintenance. However, a little extra attention will result in more blooms and lusher leaves.
Water Correctly, Not Constantly
Cannas are thirsty plants. During the heat of the summer, they may need a deep soaking two or three times a week. The goal is to keep the soil consistently moist like a wrung-out sponge. If the leaves start to roll up like cigars, it is often a sign that the plant is thirsty.
Feeding for Flowers
Because cannas grow so much biomass in a single season, they appreciate a little extra food. You can use a balanced, slow-release fertilizer at planting time, or apply a liquid fertilizer every few weeks during the peak of summer. Follow the instructions on the product label for the best results.
Deadheading
To keep the plant looking tidy and encourage it to produce more flowers, you can "deadhead" the spent blooms. When a flower cluster has finished blooming and looks withered, simply snip it off with a pair of garden shears. This prevents the plant from putting energy into making seeds and keeps it focused on creating more flowers.
Lifting and Storing for Winter
If you live in USDA zone 7 or colder, your cannas will not survive a frozen winter in the ground. However, you don’t have to buy new ones every year! You can lift the rhizomes and store them in a cool, dry place until next spring.
When to Dig
Wait until the first frost has blackened the foliage. This signal tells the plant to send all its energy down into the rhizome for dormancy. Cut the stalks down to about 4 to 6 inches above the ground.
How to Lift
Carefully use a garden fork or shovel to dig around the clump, being careful not to slice through the rhizomes. Lift the whole clump out of the dirt and gently shake off the excess soil.
Storage Steps
Let the rhizomes air dry in a garage or shed for a few days (away from direct frost). Once they feel dry to the touch, place them in a cardboard box or a paper bag filled with slightly damp peat moss, vermiculite, or even wood shavings. Store the box in a cool, dark place that stays between 40°F and 50°F, such as an unheated basement or a crawlspace. Check on them once or twice during the winter; if they look shriveled, mist them with a little water.
Enjoying the Tropical Vibe
Gardening should be a source of joy, and few plants provide as much "wow factor" for as little effort as the canna lily. From the moment you place that rhizome in the soil to the day you see the first brilliant flower, the process is a rewarding journey. Whether you are planting a single pot for your porch or a long row along a sunny fence, cannas will bring a touch of the tropics to your home.
We invite you to experiment with different foliage colors and heights to find the combination that speaks to your style. With the right orientation, plenty of sun, and a bit of water, your cannas will thrive and provide beauty all season long. You can always rely on us at Longfield Gardens for quality rhizomes and the support you need to grow a more beautiful garden.
Final Key Takeaway Planting cannas is as simple as finding a sunny spot, waiting for warm soil, and placing the rhizome 4-6 inches deep with the eyes facing up. Their resilience and rapid growth make them a perfect choice for gardeners of all skill levels.
To get started with your tropical garden, check your soil temperature and prepare your sunny spots today!
FAQ
What happens if I accidentally plant my canna rhizome upside down?
Don't worry! Cannas are very determined plants. If the eyes are facing downward, the shoots will simply grow around the rhizome to reach the surface. It might take a few extra days for the sprout to appear, but the plant will still grow and bloom successfully.
Can I grow tall canna varieties in pots?
Yes, you can, but you will need a large, heavy container. Tall cannas can become "top-heavy" and may blow over in the wind if the pot is too small or light. Choose a container that is at least 18 inches in diameter and use a heavy potting mix to provide stability.
Do canna lilies attract pollinators?
Absolutely! The bright, tubular flowers of cannas are a magnet for hummingbirds, who love the nectar. You may also see bees and butterflies visiting the blooms throughout the summer, making them a great choice for a pollinator-friendly garden.
How long does it take for a canna rhizome to sprout?
In warm soil (60°F or higher), you can usually expect to see green shoots within 2 to 3 weeks. If the soil is cooler or the rhizome was very dry, it may take up to 4 weeks. Starting them indoors can help speed up this process for the outdoor season.