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Calla lily bulbs can be left in the ground, but whether you should leave them depends on your climate and garden conditions.
In warmer climates, calla lily bulbs often survive the winter comfortably when left in the ground.
However, in colder zones, it’s usually best to dig them up, store them indoors, and replant them in the spring.
This post will walk you through the details of whether calla lily bulbs can be left in the ground, how to care for them if you do, and tips for overwintering in various climates.
Let’s dig in!
Why Calla Lily Bulbs Can Be Left in the Ground in Some Conditions
Not everyone realizes it, but calla lily bulbs can be left in the ground safely in certain climates.
Here’s why calla lily bulbs can be left in the ground and what makes that possible:
1. Calla Lilies Are Hardy in Mild Winters
In USDA zones 8 to 10, calla lily bulbs thrive if left planted outside.
The soil rarely freezes hard enough to damage the bulbs.
They can survive mild winters by entering dormancy underground and emerging again when warmth returns.
2. Natural Insulation from Soil Protects Bulbs
The soil acts like a natural blanket for calla lily bulbs, buffering them from sudden temperature drops or frosts.
Leaving bulbs in the ground lets them stay protected compared to exposure above ground.
This makes it easier for the bulbs to restart growth in spring.
3. Less Disturbance Means Healthier Bulbs
Bulbs that remain undisturbed in the soil tend to stay healthier over multiple growing seasons.
When you leave calla lily bulbs in the ground, you avoid the risk of damage from digging or accidentally cutting the bulbs.
Bulbs can continue producing beautiful flowers year after year when given this stability.
When You Should Not Leave Calla Lily Bulbs in the Ground
While calla lily bulbs can be left in the ground, there are situations where removing and storing them is a better choice.
1. Cold Winters Can Kill Calla Lily Bulbs
In USDA zones below 8, winter cold can freeze the bulbs and cause rot or death.
So if you live where the ground freezes deeply or remains below freezing for extended periods, your calla lily bulbs are safer lifted in fall.
2. Wet Soil Leads to Bulb Rot if Left in the Ground
Calla lily bulbs don’t like overly wet or soggy soil through winter.
If your soil tends to hold water or doesn’t drain well, leaving bulbs in the ground risks rot.
Lifting and storing bulbs indoors can protect them from moist conditions.
3. Pest and Disease Problems Make Removal Safer
Sometimes pests like rodents or fungal diseases can threaten bulbs left underground.
If you notice infestation or disease issues, it makes sense to lift bulbs to inspect, treat, and store them safely away from problems.
Best Practices for Leaving Calla Lily Bulbs in the Ground
If you decide calla lily bulbs can be left in the ground in your garden, a few tips will ensure their success:
1. Plant Bulbs in Well-Draining Soil
Good drainage is key to preventing rot.
Amend heavy or clay soils with organic matter or sand to improve drainage before planting.
Bulbs sitting in soggy soil during winter are vulnerable to decay.
2. Mulch After the First Frost
Applying a thick layer of mulch over the bulb area after the first hard frost helps protect against temperature swings.
Mulch acts as an extra insulating layer, reducing the risk of freeze damage.
Use pine needles, shredded leaves, or straw for natural mulch options.
3. Water Calla Lilies Appropriately
Reduce watering after the growing season ends and the plant enters dormancy.
Overly wet bulbs in winter invite rot and fungal problems.
If you live in a rainy area, ensure your planting spot sheds excess water well.
4. Monitor for Signs of Stress or Pests
Keep an eye on your calla lilies during the growing season and after dormancy starts.
If you notice bulbs are soft, mushy, or chewed by animals, consider lifting and storing them the next season.
Early intervention preserves bulb health for years ahead.
How to Overwinter Calla Lily Bulbs if They Shouldn’t Be Left in the Ground
If your climate or garden conditions mean calla lily bulbs cannot be left in the ground, here’s how to care for them after digging up:
1. Lift Bulbs After Foliage Dies Back
Wait until the leaves yellow and die naturally, which signals the bulbs are fully dormant.
Carefully dig bulbs out using a garden fork or shovel to avoid damage.
Shake off excess soil but don’t wash the bulbs, as extra moisture promotes rot.
2. Cure Bulbs in a Warm, Dry Spot
Place bulbs in a dry, shaded area with good air circulation for about 1–2 weeks.
This curing process toughens bulb skins and reduces moisture before storage.
3. Store in a Cool, Dry Location for Winter
Store bulbs in breathable containers like paper bags, boxes lined with peat moss, or sawdust.
Keep the storage area dry and cool — about 50°F (10°C) works well — with good air flow.
Avoid plastic bags that trap moisture and cause mold.
4. Replant Calla Lily Bulbs in Spring
As temperatures warm and frost threat passes, replant calla lily bulbs in prepared soil.
Position bulbs about 3-4 inches deep, spaced 12 inches apart for best growth.
Water well after planting to help bulbs re-establish.
Common Questions About Leaving Calla Lily Bulbs in the Ground
Many gardeners ask questions about calla lily bulbs’ winter habits and care if left outside.
Q: Do Calla Lilies Come Back Every Year If Left in the Ground?
Yes, in mild climates where bulbs survive the winter, calla lilies typically return each growing season.
They go dormant underground, resting until warm weather triggers new growth.
Q: How Do I Tell If Calla Lily Bulbs Need to Be Lifted?
If you live in a colder zone, or notice bulbs getting soft, mushy, or eaten by animals, it’s time to lift them.
Signs of frost damage or poor drainage also mean bulbs won’t survive winter below ground.
Q: Can You Leave Calla Lily Bulbs in Containers Outside?
Calla lily bulbs in pots outdoors face more risk from cold since pots freeze faster than ground soil.
For safety, either bring pots indoors during winter or treat them like bulbs that need lifting and storing.
Q: What Temperature Is Too Cold for Leaving Calla Lily Bulbs Outside?
Calla lily bulbs generally cannot tolerate soil temperatures below 20°F (-6°C).
If your winters routinely drop below this, it’s best not to leave the bulbs in the ground without heavy insulation or lifting them.
So, Can Calla Lily Bulbs Be Left in the Ground?
Calla lily bulbs can be left in the ground in regions with mild winters and well-draining soil.
For gardeners in USDA zones 8 and warmer, leaving bulbs undisturbed can lead to beautiful plants returning year after year.
However, in colder climates or areas with soggy winter soil, it’s safer and wiser to lift and store calla lily bulbs through the cold months.
Whether you leave bulbs in the ground or bring them in for winter, the key is protecting your bulbs from freezing and rot.
With the right care and conditions, calla lilies will reward you with their striking blooms season after season.
Happy gardening!