How Often to Water Calla Lily Plants?

Calla Lilies are a type of flowering plant that’s native to South Africa. With their beautiful trumpet flowers and spear-like foliage, they’re typically used for decoration both indoors and outdoors. If you’re wondering how often to water Calla Lily plants, well, it depends on multiple factors.

Although Calla Lilies naturally grow around marshes and river banks, drenching their soil isn’t a good idea. Calla Lily should be watered regularly, but the soil must be well-drained to avoid rot from attacking the tubers and stems. Watering Calla Lilies can be as little as once a week, depending on evaporation and drainage of the soil.

To find out more about good care and watering habits for Calla Lilies, keep reading!

water dripping out of the metal watering can

How Often Should You Water Calla Lilies?

Calla Lilies are a great, low-maintenance option for beginners in the world of gardening as they grow fast, require minimal care and pruning, and don’t need to be watered or watched every single day. 

Although care for Calla Lily plants differs depending on whether they’re grown in soil or in a flower pot, the common wisdom is to water them minimally. Once a week is enough in regular conditions, but you should check the soil if you suspect it’s too dry.

If you live in an area where there’s not enough ambient humidity, you can water them more often. Just be careful not to overwater them, as it creates a new set of problems.

white calla lilies and big green leaves over dark water

Can You Overwater Calla Lily Plants?

The answer is a plain and simple yes! 

Calla Lilies don’t thrive in conditions where their growing medium is too soggy. We mentioned above that the plant in its native environment grows along river banks and marshes, and that sounds awfully wet!

However, the key element in this equation is drainage. Water has to pass through the soil to allow just enough hydration for the root without letting the tuber or stems sit in it for too long. If that doesn’t happen, the plant parts get waterlogged and problems start to show.

An overwatered Calla Lily will have mushy, soft stems. The tuber might also start getting soggy, spotty, or have a foul smell, and all of this points to the plant being affected by soft rot.

What Is Soft Rot? And How to Prevent It?

Soft rot is a bacterial plant disease where certain bacteria secrete chemicals (called enzymes) that eat away at the plant structure. 

Stems and roots are mainly made of cellulose, a rigid, complex carbohydrate. The bacterial enzymes start to dissolve cellulose, forming less complex molecules that retain water like a sponge.

If your Calla Lily plant sits in soggy soil for too long, it’s surrounded by that bacteria. After a while, the tuber part of the plant gets mushy and the stems fail to support the weight of the flowering parts. You can spot that by squeezing the stem and noticing watery sap running out.

The most important tip to prevent soft rot is to make sure your growing medium drains excess water efficiently. If you’re planting your Calla Lilies in a garden, add properly decomposed vegetable compost or manure before you place your tubers. That usually balances out the structure of the soil.

As for container planting, consider a soilless potting mix for your Calla Lilies. These are made of organic materials like peat moss, perlite, wood chips and/or dust, and coco coir. They allow for better drainage than normal garden soil, which can get compacted and trap moisture without constant agitation by tilling or worm activity.

That said, there’s no cure for overwatering your plants as effective as prevention. Consider keeping a garden/plant journal to keep tabs on the condition of each of your plants, along with their respective watering schedules. This should help you be more conscious of the amount of water going into each one.

two white calla lilies with water droplets

Can You Save A Calla Lily Plant Infected with Soft Rot?

If you catch your Calla Lilies looking droopier than usual and suspect soft rot, immediately cut off the damaged parts with disinfected pruning shears. 

You should then transplant the tuber to a clean pot/area of the garden, and monitor its growth over the next few days. 

You should avoid using the same shears for other plants before disinfecting them again, as soft rot is contagious and can affect the other plants as well.

Calla Lily Care for Each Season

Here are a few tips on how to care for your Calla Lilies throughout the year. Keep in mind that these tropical plants are treated as perennial in US hardiness zones 8–10. 

Those in cooler areas can treat them as annuals, or dig up the rhizomes before the first frost, store them, and then replant them the following spring.

Spring

If this is your first batch of Calla Lilies, you should prepare the soil by adding organic fertilizer. Then, proceed by placing the tuber, “eye” side up, under 3–4 inches of soil. Pack it lightly, then water it once a week. 

The first shoot should appear about two weeks later. Keep watering regularly, and use liquid fertilizer dissolved in a watering can once a month for better blooming.

Summer

Calla Lily plants usually take between 13–16 weeks to flower, depending on the cultivar and growing conditions. If you’re in the perennial zone, this could happen from late spring to early summer. In cooler areas, it’s late summer to early fall.

Keep an eye on the amount of water in the soil, since evaporation rates are higher during the summer. With that said, if you live somewhere that gets a lot of sun, try putting your Calla Lily plants somewhere a little shady to avoid overheating.

Liquid fertilizer in water once a month will keep the flowers blooming for longer. Just avoid nitrogen-heavy fertilizers, as they can make your Calla Lily plant very leafy without many flowers. Opt for more balanced plant food with enough phosphorus to encourage flowering.

Fall

Calla Lilies usually die back after 3–8 weeks of blossoming. After the blooms begin to fade, start deadheading them along with any yellowing leaves. 

As soon as the whole plant yellows, trim the stems to soil level (1–2 inches) to avoid dead plant material rotting the tuber.

If you live in hardiness zone 8–10, you can leave the tubers in the ground over winter. However, if there’s any danger of frost, it’s wise to remove the tuber from the ground, clean it, make sure it “cures” in a dry place for two days, then store it in a box with slightly damp peat moss.

Winter

Check on your tubers every once in a while, you should notice the tuber hasn’t changed much. If the storage location is too damp, it can lead to rotting, if it’s too dry, the tuber might shrivel up and die.

Once the last frost is gone, you can take out your Calla Lily rhizomes and replant them for the coming spring. 

If the soil temperature is over 65℉, you can plant it in the ground right away. If it’s still too cold out, you can start the plant in a pot before transplanting it after the weather gets warmer.

To Wrap Up – How Often to Water Calla Lily Plants

Calla Lilies are the optimal choice for a breathtaking view that doesn’t require back-breaking work. And since they come in many varieties, you’re bound to find one that fits in your garden or your flower pots.

The most important thing when you’re caring for your Calla Lily plants is to make sure they’re not being overwatered. Waterlogging the tuber and stems can create many problems, the worst of which is soft rot that eats away at the plant at a molecular level.

Before you start growing Calla Lilies, take a moment to enrich the garden soil with fertilizer, or choose a quality potting mix to place them in. This can make all the difference when it comes to proper drainage.