Peace Lily vs Calla Lily: Differences Explained

Have you ever wondered what the differences between a peace lily and a calla lily are?

These two plants sometimes get confused, but they are quite different from each other. Some of their major differences include:

  • How big they get
  • The amount of light they need
  • How their foliage looks
  • The soil they like
  • The look of the flowers
  • What’s underneath the soil

It is important to understand the differences between a calla lily and a peace lily, so that you know how to look after each one, and what they need. It’s also important to know the differences so you know which you’d like in your home and which you should buy!

The Size Of The Plants

A peace lily can grow to around six feet tall and spread to about five feet wide. This is generally true of outdoor varieties only; indoor ones will usually only reach around fifteen or sixteen inches tall. 

Indoor Peace Lily
Indoor Peace Lily

Make sure you check what kind of peace lily you are buying before you get one so that you know how big it is likely to grow, and how much space to give it. If you want a large variety, make sure you choose an outdoor plant, rather than an indoor one.

Calla lilies do not get as big as the largest peace lilies, but they are still impressive plants. They usually only reach around three feet in each direction, even at their biggest. If you decide to grow one in your home, you still need quite a lot of room for it, but less than for a full-size peace lily.

The Amount Of Light

Calla lilies like to be grown in the full sun, or partial shade. They will cope reasonably well even if they do not have as much light as they like, but if you grow your plant in the sun, it will do better, and it is more likely to flower.

Your calla lily does not want to be in really hot conditions, however. Its leaves will burn if it is not provided with a bit of shade in the summer when the sun is at its strongest. You may want to put other plants nearby to provide a bit of protection from the really hot sun during the peak of the day.

Peace lilies are also reasonably tolerant of shade, but they prefer plenty of light. They do not cope well with full sun, so you will need to balance this carefully. If you are growing your peace lily indoors, position it several feet from the window.

Outdoors, you should grow it under another plant, but choose one that has a light canopy, so that your peace lily will still get some filtered sunlight on its leaves.

This will ensure that the peace lily is getting enough light to photosynthesize effectively, but will prevent it from burning. They evolved to grow on rainforest floors, and so they do not cope well with very bright and strong sunlight falling on their leaves for hours.

The Foliage

The two kinds of plants have quite different leaves, and if you see them side by side, you should be able to see the difference. 

The leaves of a calla lily look like arrowheads, and they have pointed tips. They tend to be a paler color and some have white spots on them. They may be thinner and somewhat less dramatic than a peace lily’s leaves, although both plants are beautiful in different ways.

Peace Lily vs Calla Lily Leaves

A peace lily’s leaves are broad and shaped like ovals. They tend to be glossy and dark green, and they can reach as much as two feet long each. Sometimes, a peace lily can have variegated foliage, but this depends upon the variety of the plant.

The leaves of a peace lily are often more noticeably ridged. These ridges catch the light when it falls on the plant, increasing the contrast and making each leaf look particularly delicate and dramatic.

Overall, the differences are fairly noticeable, but it is not surprising that people confuse these plants – because they aren’t strikingly different.

The Growing Medium

This is a very important difference to be aware of because it affects how you care for the plant. When you are potting the plant up, it is crucial to understand the things that the plant needs. Both enjoy quite moist soil, but there is more to their potting conditions than just this.

Callas like to be kept in very wet conditions, and can even be grown directly in water. They do not like being dried out, so if you are growing them in pots, you will need to make sure that you water them regularly.

Peace lilies, by contrast, prefer to get dried out from time to time. They still like wet conditions, but not nearly as wet as those that a calla lily prefers. If you have a peace lily, you will need to make sure that it has good drainage material at the bottom of the container or the hole that it is planted in, so that the roots don’t rot.

Both plants do like nice, rich soil to grow in, so don’t grow them in poor conditions. Choose a high-quality compost and top it up from time to time with a good fertilizer – an all-purpose plant fertilizer used properly will do the job.

The Flowers

In terms of their blossoms, peace lilies and calla lilies are fairly different. A peace lily has a white flower with a yellow spike in the center, and this flower grows in a curve around the spike.

A calla lily can produce flowers in all kinds of different colors, including cream, purple, pale pink, yellow, or red. There is still a central spike, and the flower is approximately the same shape as a peace lily’s flower. The spike tends to be less pronounced on a calla lily, and because there is less color contrast, it may not show up as well.

The top of the calla lily’s flower is sometimes somewhat flatter. It looks more like a trumpet, although this does depend on the individual plants a bit. However, the two do share some similarities in their elongated stems and in the way that the flower petals cup around the central spike.

It is also worth noting that a calla lily will only flower in the summer when the weather is warm and there is lots of light. A peace lily will flower at any time of the year, provided it has enough warmth and light. If you use a grow lamp, you can get a peace lily to flower in the middle of winter in some cases!

Roots/Rhizomes

Although the plants share some similarities above the soil, they are very different if you dig down below the surface of the earth. You might notice this when you come to put your plant into your garden.

A peace lily, for example, has a ball of tangled roots that look very much the way most plants’ roots look. These spread throughout the soil, gathering moisture and nutrients for the plant to use, and keeping it anchored to the ground.

The roots of a peace lily do not look particularly unusual or remarkable.

By contrast, a calla lily grows from rhizomes. These are large clusters of what looks like a pile of compacted dirt – but don’t be fooled. This is the plant’s emergency supply, and while it may look different, it is very important to the plant. You don’t want to try and break it up with a trowel or secateurs.

They can be quite bulbous and blobby, and they are a pale brown color. From them, lots of little roots should be sprouting. Again, these spread throughout the soil, absorbing nutrients and moisture so that the calla lily can continue to grow.

Often, the roots will look out of proportion with the rhizome, being very thin. This is normal, and nothing to worry about.

You might be wondering what purpose the rhizomes serve. The answer is that they provide the plant with a store of food, and this can help it survive through an unfavorable season. The roots carry nutrients into the rhizomes, and these nutrients are stored there so that the plant can access them whenever it needs to.

Overall, then, the peace lily and the calla lily have some noticeable differences once you get underground and start inspecting their growth mechanisms!

Conclusion

Many people confuse calla lilies and peace lilies, and this may be because they look quite similar in some ways. Both plants grow flowers that are quite unusual, but very similar to each other, and both have long, bright green leaves.

However, if you look more closely at the plants, you will start seeing major differences between the two, in terms of their behavior, their needs, and their evolutionary quirks.