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How Do You Winterize Calla Lilies?
You winterize calla lilies by lifting their rhizomes from the ground before the first hard frost and storing them in a cool, dry place until spring.
That’s the short answer, but the full process involves a few careful steps to make sure your calla lilies survive the cold months and come back vibrant when warm weather returns.
Calla lilies are tender perennials, which means they can’t handle freezing temperatures like hardy bulbs such as tulips or daffodils.
If you live in USDA zones 8 or warmer, you might be able to leave them in the ground with a thick layer of mulch.
But for most gardeners in colder climates, winterizing calla lilies means digging them up and giving them a cozy indoor hibernation spot.
In this post, we’ll walk you through exactly how to winterize calla lilies, whether you’re dealing with potted plants or garden beds, and share tips to keep those rhizomes healthy all winter long.
Let’s dig in.
Why You Need to Winterize Calla Lilies
Calla lilies originally come from southern Africa, where winters are mild and frost is rare.
That tropical heritage means they simply aren’t built to survive icy soil.
When temperatures dip below freezing, the water inside their rhizomes can freeze, causing cell walls to burst and turn the plant into mush.
So if you want to keep enjoying those elegant trumpet-shaped blooms year after year, you need to winterize calla lilies before Jack Frost arrives.
The good news is that the process is straightforward once you know the timing and techniques.
Know Your Growing Zone First
Before you start digging, check which USDA hardiness zone you live in because your zone determines your winterizing strategy.
If you’re in zone 8 or above, your winters are mild enough that calla lilies can stay in the ground with a protective mulch blanket.
But if you’re in zone 7 or colder, you absolutely must lift the rhizomes and store them indoors.
A quick online search or a look at your local extension office website will tell you your exact zone.
This simple step saves you from guessing wrong and losing your beloved lilies.
When to Start the Winterizing Process
Timing is everything when you winterize calla lilies.
You want to wait until the foliage has been hit by a light frost but before a hard freeze settles in.
A light frost will cause the leaves to yellow and die back, which is actually a good sign because it signals the plant is entering dormancy.
A hard freeze, on the other hand, can damage the rhizomes even while they’re underground.
So watch your local forecast and aim to dig them up about two weeks after the first light frost, or anytime before the ground starts to freeze solid.
Step-by-Step Guide to Winterize Calla Lilies
Now let’s get into the hands-on part of winterizing calla lilies, from digging to storing.
Follow these steps and your rhizomes will thank you come spring.
1. Cut Back the Foliage
Once the leaves have yellowed and flopped over, trim them down to about 2 to 3 inches above the soil line.
Use clean, sharp pruners to make a clean cut and avoid tearing the stems.
This tidying step makes digging easier and prevents the foliage from rotting during storage.
Don’t pull the leaves off forcefully, as that can damage the crown of the rhizome.
2. Dig Up the Rhizomes Carefully
Use a garden fork or a spade to gently loosen the soil around each plant, staying about 6 to 8 inches away from the stem.
Insert the fork at an angle and lift upward slowly to avoid slicing through the rhizomes.
Shake off the excess soil, but don’t wash them with water yet because wet rhizomes are more prone to rot during storage.
If you’re winterizing calla lilies that were planted in pots, simply dump the entire pot out onto a tarp and separate the rhizomes by hand.
3. Cure the Rhizomes Before Storing
Curing is a crucial step that many gardeners skip, and it’s the secret to successful winterizing calla lilies.
Place the dug-up rhizomes in a single layer on a tray or cardboard box in a warm, dry, well-ventilated area.
Let them sit for about a week so any remaining soil dries out and the skin toughens up a bit.
This hardening-off period helps prevent mold and rot during the long months in storage.
Just make sure they’re not in direct sunlight, which can dry them out too much.
4. Trim Roots and Remove Damaged Parts
After curing, shake off the remaining dry soil and inspect each rhizome closely.
Trim off any long, stringy roots with scissors to keep things tidy.
Cut away any soft, mushy, or discolored spots with a clean knife, as these can spread rot to healthy tissue.
If you find serious damage, it’s better to discard that rhizome entirely so it doesn’t affect your others.
5. Choose the Right Storage Material
Now it’s time to pack them up properly.
You have a few good options for storing winterized calla lilies:
– Peat moss or vermiculite in a breathable paper bag
– Dry sand or wood shavings in a cardboard box
– Perforated plastic bags filled with slightly damp (not wet) peat moss
Avoid using sealed plastic containers that trap moisture, as that’s a fast track to rot.
Layer the rhizomes so they’re not touching each other, and label the container with the variety and the date.
6. Store in a Cool, Dark Place
The ideal storage spot is a cool, dark, and dry location with a temperature between 45°F and 55°F (7°C to 13°C).
A basement, garage, or unheated closet often works perfectly.
Avoid areas that freeze or get too warm, like an attic in summer or an uninsulated shed in winter.
Check on your stored rhizomes once a month to remove any that show signs of mold or shriveling, and lightly mist the storage medium if it feels bone dry.
How to Winterize Calla Lilies in Pots
If your calla lilies live in containers, you have an easier option than digging them up, but you still need to winterize calla lilies properly.
You can simply move the entire pot into a cool, dark room like an unheated garage or basement.
Allow the soil to dry out completely and cut back the foliage once it dies back.
Don’t water the pot at all during winter, as the rhizomes need a dry rest period.
In spring, you can either repot fresh soil or gently remove the rhizomes and plant them outside again.
This in-pot method works great if you have the space and a suitable cool location.
So, How Do You Winterize Calla Lilies?
You winterize calla lilies by lifting them from the ground before a hard freeze, curing them for a week, trimming damaged parts, and storing them in peat moss or sand at a cool 45–55°F.
The process is simple once you break it down into those steps, and it guarantees your calla lilies will wake up healthy and ready to bloom next season.
Whether you’re digging from garden beds or moving pots inside, the key is to keep them dry, cool, and free of rot.
So don’t let a little winter weather stop you from enjoying these stunning flowers year after year.
Follow this guide, and your calla lilies will be back to show off their graceful blooms just as soon as the soil warms again.