Are Calla Lilies Annual, Perennial, or Biennial Plants?

If you find yourself looking into calla lilies, you are likely looking for a unique and tropical bloom that will be a conversation piece for your indoor or outdoor garden. These delightful flowers bring joy and bright enjoyment everywhere they are planted. It is nearly impossible to look at a grouping of this tropical beauty and not be amazed.

A common question you might encounter is, “Are calla lilies annuals or perennials?” This is a perfectly reasonable question, considering they are so beautiful that most people would probably hope that they stick around for decades at a time.

But introducing them into your garden requires a little more understanding of how they work, what they do, and whether or not they will survive in your climate. Taking a journey through some helpful information will lend itself toward your quest and make your final decision much easier.

Are Calla Lilies Annuals or Perennials?

Calla lilies are perennial flowers, meaning that they live at least two years at a fundamental level. They prefer to grow around ponds, streams, or rivers. The calla lily can thrive all year through more than one growing season with the right temperature and climate.

Perennial plants are different from both annuals and biennials. Perennials tend to grow and bloom through the spring and summer when conditions are generally more favorable. They die back as the weather turns in autumn and winter and then return by the following spring.

The rootstock is generally responsible for a plant’s ability to sustain itself through the long winter months without dying completely. A rootstock sits underground most of the time, protected from harsh weather conditions. 

They have rootstock that keep them alive during the winter months and bring them back each spring.

Calla Lilies: An Overview

Calla lilies are known as rhizomatous herbaceous perennial plants. This means they have an underground root system that sends out roots, they have no woody stems above ground but are vascular, and they return every year. They come in many colors, but are one of the few true black perennial flowers you can grow.

Native to southern Africa, they can be both evergreen and deciduous, depending on the climate in which they reside. An evergreen calla lily will bloom multiple times throughout the year, usually corresponding to different planting and growing cycles.

They tend to be evergreen in temperate climates where rainfall is plentiful.

When a calla lily is deciduous, it loses all of its leaves after the summer months. Throughout the colder autumn and winter months, it will not bloom again. While it remains alive because of its rootstock, the part of the plant that resides above ground cannot grow or bloom.

They are more deciduous in climates that have regular dry seasons when rainfall levels drop significantly. Native to southern Africa, you may also find them growing naturally in New Zealand and other parts of Australia and California.

They have naturalized in some locations across eastern Africa, proving their resilience and ability to spread quickly under the right conditions.

One of the most exciting things about these perennial plants is that they are not true lilies. They are similar, but they live in a different plant family. 

Hardiness Zones

In the U.S. Department of Agriculture’s plant hardiness zones, we can see how different plants respond under other climate circumstances. These perennial plants, thrive in zones 8-11.

The USDA plant hardiness zones 8-11 include portions of the Pacific coast, stretching from Washington state to Southern California. This includes parts of southwestern Arizona, as well as southwestern New Mexico. The tip of southern Nevada, southern Utah, and parts of northwestern Arizona rest in zones 8 and 9.

Most of Texas rests in these zones, although the panhandle section does not. The zones stretch east, covering all of Louisiana and most of Mississippi, Alabama, Georgia, and the Carolinas.

Florida divides between zones 8-10, and parts of Hawaii are included in zone 11. A tiny portion of southern Arkansas rests in zone 8.

They can proliferate as perennials in these parts of the United States. Although many of these climates have a dry season, the lilies can thrive without the lousy winter months that plague the northern states.

In other zones, where the weather is wetter, you might experience your calla lilies suffering from root rot. Root rot can happen when the soil gets too wet or cool. You can treat them like annuals and replace them every year in these circumstances.

There are also easy ways to preserve these flowers during the winter months if you’re concerned about temperatures dropping too low. Let’s look at some of those methods next.

Winter Care

Because they are native to temperate, warmer climates, calla lilies are not necessarily winter-hardy. They thrive in USDA plant hardiness zones 8-11 because the winter months are not harsh, so they don’t need to be dug up.

When they stay out in bad winter weather, the plants can be severely damaged and even die off completely. Generally, temperatures below 25 degrees Fahrenheit aren’t suited for these flowers, making them prone to die.

If you want to keep these plants alive during the winter months and live in a USDA plant hardiness zone that’s less than 8, you will have to take special precautions.

Outdoor & Indoor Preservation

One way to keep your calla lilies alive during bad winter months is to dig them up and store them inside or in a greenhouse.

When you dig them up, you want to be careful not to damage the rhizomes. Store them in a vented container with good soil that drains quickly. You don’t want too much moisture, or root rot can set in soon.

After your They have stopped flowering, stop watering them. This will encourage them to enter a dormant state when the foliage begins to die back.

You can remove them at this stage or remove the ground-level portion and cover the root zone with four inches of mulch.

If you need to remove the bulbs from the ground, you must do so carefully. You can wait until after the first frost, making cutting away the foliage much easier.

Careful not to puncture the rhizomes as you dig, gently dig, and loosen the dirt around the roots so you can find the root ball. Try to keep it in one clump as you pull it from the ground. You can lightly spray it to clean it before storage.

Division and Expansion

Once you have the bulbs out of the ground, you have an excellent opportunity to divide the calla lilies and prepare them for more planting next year. You can gently pull the root clumps apart or use a knife.

Storing your separated clumps with some fungicide will help keep them healthy, especially if you intend to replant them in multiple sections next year.

You can use a tray or a piece of cardboard to arrange your calla lily bulbs. Make sure to keep some distance between them.

You’ll let them dry slightly on the tray before you finish preparing them for storage in a vented container with suitable vermiculite or another substrate.

Growing as Perennials

Growing perennials might seem like a lot of work, but it is worth it. A few of the key benefits of increasing perennials include:

• Saving money
• Enjoying flowers every year
• Cultivating and sharing with others
• A great science project for kids and grandkids
• The joy of caring for the same plant

There is something to be said for people who take special care of their plants. Perennials require a lot of attention, especially calla lilies that don’t survive well in certain climates.

But that care will only make you love the plants even more. And isn’t gardening supposed to be something of a labor of love?

Can You Grow Them as Annuals?

As you have already seen, you can grow these tropical flowers as annuals if you need to. Some USDA plant hardiness zones require extra care for them to survive winter. If you aren’t interested in putting in the extra work, treating them like annuals might be a better option.

While these flowers are perennials, there’s nothing wrong with growing them like annuals if that’s what you prefer. However, taking the time to preserve them can bring joy to many people who might benefit from fresh bulbs to add to their gardens.