Introduction
There is nothing quite like the sight of a canna lily in midsummer. With their massive, paddle-shaped leaves and vibrant, tropical blooms, they turn any backyard into a lush getaway. Whether you are planting them in large patio pots or as a dramatic backdrop in your garden beds, cannas bulbs for sale bring an undeniable energy to the landscape. At Longfield Gardens, we love how these plants offer so much visual impact for relatively little effort.
If you are holding a handful of canna "bulbs"—which are technically called rhizomes—you might be wondering how to give them the best possible start. One of the most common questions we hear is whether you should soak them in water before they go into the soil. Some gardeners swear by it, while others skip it entirely.
This guide will explain when soaking is helpful, how to do it correctly, and the other simple steps that matter even more for growing healthy, beautiful cannas. We want to help you feel confident as you begin your gardening season. Soaking can be a great way to "wake up" your plants, but it is just one part of the process.
The short answer is that soaking is not strictly necessary, but it can help kickstart growth, especially if the rhizomes have become very dry during storage.
The Canna Wake-Up Call: Why Soaking is a Topic
Before we dive into the "how," it helps to understand what a canna rhizome actually is. While most people call them bulbs, they are actually thickened underground stems. These stems store energy and water, allowing the plant to survive through its dormant period in the winter and push out new growth once the weather warms up.
When you receive your canna rhizomes in the spring, they have been resting in a cool, dry environment. This dormancy is important for the plant's health, but it can make the rhizome look a bit shriveled or feel very firm and dry. The idea behind soaking is to rehydrate the tissues and signal to the plant that the growing season has begun.
Think of soaking as a gentle "wake-up call." By providing a boost of moisture directly to the rhizome, you may find that the plant sends up its first shoots a few days earlier than it would otherwise. However, cannas are incredibly resilient plants. Even without a soak, they will eventually find the moisture they need from the surrounding soil, provided you keep them watered after planting.
Key Takeaway: Soaking is a tool to speed up the transition from dormancy to active growth, but it is an optional step for most healthy canna rhizomes.
How to Decide If Your Canna Rhizomes Need a Soak
Not every canna rhizome needs a bath before it hits the dirt. The decision usually depends on the condition of the rhizome and your specific gardening goals.
Check the Texture
When you open your package from us, take a close look at the rhizomes. A healthy canna rhizome should feel relatively firm, much like a fresh ginger root or a potato. If the rhizome feels heavy for its size and the skin looks plump, it likely has plenty of internal moisture. In this case, you can plant it directly into the soil without soaking.
If the rhizome feels very light or looks significantly wrinkled and shriveled, it has lost some moisture during its winter nap. These are the best candidates for soaking. A quick soak will help the "eyes"—the small bumps where new stems will grow—become more prominent and ready to sprout.
Consider Your Timing
Are you trying to get a head start on the season? Many gardeners in northern climates start their cannas indoors in pots before the last frost. If you are eager to see green leaves as soon as possible, soaking can help shave a few days off the sprouting time. If you are planting directly into warm garden soil in early summer, the natural warmth and moisture of the earth are usually enough to get things moving without extra help.
Identify the "Eyes"
Take a moment to look for the growing points, or eyes. They often look like small, pointed nubs on the surface of the rhizome. If you can already see small green or white tips starting to emerge, the plant is already awake! These rhizomes are ready to go and do not necessarily need a soak.
What to do next:
- Inspect each rhizome for firmness.
- Separate any that look particularly dry or shriveled.
- Decide if you want to soak all of them for a uniform start or just the dry ones.
The Simple Steps to Soaking Your Canna Bulbs
If you decide that a soak is the right move for your cannas, the process is very straightforward. You do not need any special equipment or complicated chemicals.
1. Use Room Temperature Water
Fill a shallow bowl, bucket, or tray with clean, room-temperature water. Avoid using very cold water from a garden hose, as a sudden temperature drop can shock the dormant tissues. Lukewarm water is much gentler and more effective at hydrating the rhizome.
2. Time it Right
The most important rule of soaking is not to overdo it. Canna rhizomes only need about 2 to 4 hours in the water. This is enough time for the outer layers to absorb moisture without the risk of the internal tissues becoming waterlogged.
Avoid soaking them overnight or for several days. If a rhizome sits in standing water for too long, it can begin to rot before it ever has a chance to grow. If you get busy and forget them for an extra hour, do not worry—just get them into the soil as soon as you can.
3. Optional Additions
While plain water works perfectly well, some gardeners like to add a small amount of liquid seaweed extract or a very diluted, water-soluble fertilizer to the soaking bath. This provides a tiny hit of nutrients to the emerging roots. However, this is purely optional and is not a requirement for success.
4. Plant Immediately
Once you take the rhizomes out of the water, they should be planted right away. You don't want them to dry out again after you have gone to the trouble of hydrating them. Have your pots or garden beds ready before you start the soaking process.
"The goal of soaking is to hydrate, not to drown. A few hours is plenty of time to give your cannas the boost they need to start the season strong."
Beyond Soaking: The Essentials for Canna Success
While soaking can give your cannas a slight edge, it is not the most important factor in their success. At Longfield Gardens, we believe that getting the basics right is the surest way to a beautiful garden. If you follow these simple rules, your cannas will thrive whether you soaked them or not.
Temperature is Everything
Cannas are tropical plants at heart. They love heat and will sit dormant in the ground if the soil is too cold. The single most common reason for cannas failing to sprout is planting them too early in cold, damp soil.
Wait until the soil temperature reaches at least 60°F before planting them outdoors. In most parts of the US, this happens a few weeks after the last frost date. If you have a soil thermometer, it can take the guesswork out of the process. If the ground still feels chilly to the touch, it is better to wait.
Sun, Sun, and More Sun
To produce those iconic, large leaves and bright flowers, cannas need fuel. That fuel comes from the sun. Choose a location that receives at least 6 to 8 hours of direct sunlight each day. While they can grow in partial shade, they will likely be shorter, produce fewer flowers, and the foliage colors won't be as intense.
Drainage and Soil Quality
Cannas are unique because they actually enjoy more moisture than many other garden bulbs. They are often found growing near ponds or in damp areas. However, "moist" is not the same as "soggy."
The soil should be rich in organic matter, such as compost or well-rotted manure, which helps hold moisture while still allowing excess water to drain away. If your soil is heavy clay and stays like a sponge for days after a rain, consider planting your cannas in raised beds or containers to improve drainage. "Drainage" simply means the speed at which water moves through the soil; you want it to stay damp but never like a swamp.
Starting Your Cannas Indoors for an Early Bloom
If you live in a region with a short summer, you might want to start your canna rhizomes indoors about 4 to 6 weeks before the last frost. This gives them a "head start" so they are already a foot tall by the time the weather is warm enough to move them outside.
Choosing the Right Pot
Use a pot that is at least 6 to 8 inches wide for a single rhizome. Ensure the pot has drainage holes at the bottom. Since these plants will eventually grow quite large, you don't want them to become "root-bound" (where roots grow in circles around the pot) before you can get them into the garden.
Planting Depth and Direction
Fill your pot with a high-quality potting mix. Place the rhizome horizontally in the soil. Look for the "eyes" or any small sprouts and point those upward. If you can't tell which way is up, don't worry—cannas are smart enough to send their shoots toward the light and their roots toward the water.
Cover the rhizome with about 2 to 3 inches of soil. If you soaked your rhizomes, they will be ready to start growing immediately.
Heat and Water
Keep the pots in a warm spot. A sunny windowsill is good, but a heat mat designed for plants can work wonders for cannas. They sprout much faster when the soil is warm. Water them just enough to keep the soil moist, but be careful not to overwater before you see green growth. Once the leaves appear, you can increase the watering.
What to do next:
- Find a warm, bright indoor spot for your pots.
- Label each pot with the variety name.
- Monitor the soil moisture daily.
Planting Cannas Directly in the Garden
If you prefer to skip the indoor start, planting directly into the garden is a simple and rewarding process. This is the best approach for gardeners in warmer zones or those who have plenty of time for the plants to mature before autumn.
Site Preparation
Before you plant, take a moment to prepare the soil. We recommend mixing in a few inches of compost. This provides slow-release nutrients and improves the soil's ability to hold water, which cannas love.
Spacing and Depth
Dig a hole about 4 to 6 inches deep. If you are planting multiple cannas, space them based on their mature size. Dwarf varieties can be planted about 12 inches apart, while tall, standard varieties need 18 to 24 inches of space to allow for good air circulation.
Place the rhizome horizontally in the hole with the eyes facing up. Backfill with soil and press down gently with your hands to remove any large air pockets.
The First Water
After planting, give the area a deep watering. This settles the soil around the rhizome and ensures there is good contact between the plant and the earth. If you didn't soak your bulbs beforehand, this first watering is particularly important to trigger the end of dormancy.
Key Takeaway: Correct depth and warm soil are the quiet winners of canna gardening. Get these right, and the plant will do the rest.
Caring for Your Cannas Through the Season
Once your cannas have sprouted and are reaching toward the sky, they are relatively low-maintenance. However, a little bit of consistent care will lead to much better results.
Water Correctly, Not Constantly
Cannas are thirsty plants. During the heat of the summer, they may need water several times a week. The goal is to keep the soil consistently moist. If the edges of the leaves start to turn brown or "crispy," it is often a sign that the plant is not getting enough water.
If you have sandy soil, you will need to water more frequently because water drains through sand very quickly. In heavier soil, you can water more deeply and less often.
Feeding Your Plants
Because cannas grow so much leaf and flower material in a single season, they are "heavy feeders." This means they use up a lot of nutrients. Applying a balanced, water-soluble fertilizer every 4 to 6 weeks during the growing season will help keep the foliage lush and the flowers blooming. Follow the instructions on the fertilizer label for the best results.
Deadheading for More Blooms
As the individual flowers on a stalk begin to fade, you can pinch or snip them off. This process, called "deadheading," keeps the plant looking tidy. More importantly, it prevents the plant from putting energy into making seeds and encourages it to produce more flower spikes instead.
Pests and Problems
Cannas are generally quite tough, but they can occasionally attract pests like slugs or Japanese beetles. A quick daily check of the leaves can help you spot these early. Usually, picking them off by hand is all you need to do for a small garden.
You might also see "leaf rollers," which are caterpillars that roll themselves up inside the leaves. If you see a leaf that won't unfurl properly, check inside for these little visitors.
Preparing Cannas for Winter
In USDA zones 8 to 11, cannas can often stay in the ground all year round. A thick layer of mulch in the fall can help protect the rhizomes from occasional chilly nights.
However, if you live in zones 3 to 7, where the ground freezes hard, you will need to lift and store your canna rhizomes if you want to grow them again next year.
Lifting the Rhizomes
Wait until the first frost has blackened the foliage. This tells the plant that it is time to go to sleep. Cut the stems down to about 4 to 6 inches above the ground. Use a garden fork to gently lift the clump of rhizomes out of the earth, being careful not to bruise or cut them.
Cleaning and Drying
Shake off the excess soil. You don't need to wash them perfectly clean; a little bit of dirt is fine. Let them sit in a dry, shaded area for a few days to "cure." This allows the outer skin to toughen up slightly for storage.
Winter Storage
Store the rhizomes in a cool, dark, and dry place that stays between 40°F and 50°F. A basement or an unheated crawl space is often ideal. Many gardeners pack them in a box with slightly damp peat moss, vermiculite, or even shredded paper. This prevents them from drying out completely during the winter.
Check on them once or twice during the winter. If they look extremely shriveled, you can give the packing material a very light mist of water. If any look soft or mushy, remove them so they don't affect the others.
What to do next:
- Mark your calendar for the first expected frost date.
- Prepare a storage box with peat moss in advance.
- Enjoy the late-season blooms until the very last minute!
Conclusion
Gardening should be a rewarding and enjoyable experience, and cannas are some of the most satisfying plants to grow. Whether you choose to soak your rhizomes for a few hours to give them a head start or simply tuck them into warm, sunny soil, they are likely to reward you with a spectacular show of color.
At Longfield Gardens, we want to ensure you have everything you need for success. We stand behind the quality of our plants with a 100% quality guarantee. Our rhizomes are carefully selected to arrive at your door in prime condition, ready to grow. If you ever have a question or an issue with your order, our team in Lakewood, New Jersey, is ready to help.
The most important thing to remember is that gardening is a journey. Every season brings new lessons and new beauties. By focusing on the basics—sun, warmth, and consistent water—you can create a tropical oasis right in your own backyard.
- Soaking is a "nice-to-have," not a "must-have."
- Warm soil (60°F) is the real key to sprouting.
- Cannas need 6-8 hours of direct sun to thrive.
- Consistent moisture keeps foliage lush and colorful.
"There is no mistake in gardening that a little bit of sun and water can't eventually fix. Start with good quality rhizomes, find a sunny spot, and enjoy the magic of growth."
FAQ
Should I soak canna rhizomes if they already have sprouts?
If you see green or white sprouts already emerging from the rhizome, soaking is generally not necessary. The plant has already begun its growing cycle and is ready to be placed in soil. If the rhizome itself feels very light or shriveled despite the sprouts, a very brief 1-hour soak is okay, but be careful not to submerge the tender new growth for too long. For more general answers about bulbs and plants, see our FAQs - General Bulbs and Plants.
How long can I leave canna bulbs in water before planting?
The ideal soaking time is between 2 and 4 hours. You should never leave canna rhizomes in water for more than 12 hours. Leaving them submerged for too long deprives the plant tissues of oxygen and can lead to rot or "drowning," which will prevent the plant from growing once it is put in the soil.
Does soaking canna bulbs prevent them from rotting in the ground?
No, soaking does not prevent rot. In fact, over-soaking can actually increase the risk of rot if the rhizome becomes too waterlogged. The best way to prevent rot is to ensure your soil has good drainage and that you wait until the soil is warm (at least 60°F) before planting outdoors. If you need help timing your order, our Shipping Information page explains how Longfield Gardens ships by zone.
Can I add fertilizer to the water when soaking my cannas?
Yes, you can add a very diluted, water-soluble fertilizer or seaweed extract to the water. This can provide a small boost of nutrients to the plant as it wakes up. However, make sure the solution is very weak—usually about one-quarter of the strength recommended on the label—to avoid burning any tiny new roots that are starting to form. For help choosing a growing area, our Hardiness Zone Map can help you match plants to your climate.
