Learning how to plant calla lily bulbs is the first step to enjoying their stunning, sculptural blooms. Planting calla lily bulbs correctly in the spring sets the stage for their elegant, trumpet-shaped flowers to emerge in summer. This guide provides clear, step-by-step instructions to ensure your bulbs thrive.
How To Plant Calla Lily Bulbs
Successful planting begins with understanding the basics. Calla lilies, known botanically as Zantedeschia, grow from rhizomes, which are thick underground stems. While often called bulbs, these rhizomes store energy for the plant. The process is straightforward when you follow a few key principles.
Understanding Calla Lily Bulbs And Rhizomes
What you purchase for planting is typically a dormant rhizome. It looks like a small, lumpy tuber with several growing points or “eyes.” These eyes will sprout into stems and leaves. Healthy rhizomes are firm to the touch and show no signs of soft rot or mold. Selecting a plump, healthy rhizome is crucial for a strong plant.
Choosing The Right Bulbs For Planting
When buying calla lily rhizomes, look for these characteristics:
- Firm and solid, not shriveled or spongy
- At least one visible growth point or eye
- Free from cuts, blemishes, or dark soft spots
- A good size; larger rhizomes often produce more flowers in the first season
Best Time To Plant Calla Lily Bulbs
Timing is critical for calla lilies, as they are tender perennials sensitive to cold. The ideal planting time is in the spring, after all danger of frost has passed and the soil has begun to warm. For most regions, this is typically two weeks after the last average frost date. Soil temperature should be consistently above 60°F (15°C). Planting too early in cold, wet soil can cause the rhizome to rot.
Adjusting Planting Time For Your Climate
- Warmer Climates (Zones 8-10): You can plant rhizomes directly outdoors in early spring. They can often be left in the ground year-round.
- Colder Climates (Zones 3-7): Start rhizomes indoors in pots 4-6 weeks before the last frost. Transplant them outside once the weather is reliably warm.
Selecting The Perfect Planting Location
Calla lilies need the right spot to flourish. They perform best in a location that receives full sun to partial shade. In hotter climates, afternoon shade is beneficial to prevent scorching. The site should have well-draining soil; calla lilies enjoy moisture but will not tolerate sitting in waterlogged earth, which leads to rot.
Preparing The Soil For Optimal Growth
Soil preparation is a step you should not skip. Calla lilies prefer rich, moist, and well-draining soil. A slightly acidic to neutral pH (6.0-6.5) is ideal.
- Loosen the soil to a depth of 12-15 inches.
- Mix in a 2-4 inch layer of compost or well-rotted manure to improve fertility and drainage.
- If your soil is heavy clay, incorporate coarse sand or peat moss to enhance drainage.
- For container planting, use a high-quality, well-draining potting mix.
Step-By-Step Planting Instructions
Follow these steps for planting your calla lily rhizomes correctly.
Step 1: Inspect And Prepare The Rhizomes
Before planting, examine each rhizome. If any sections appear damaged, you can carefully cut them away with a clean, sharp knife. Some gardeners soak the rhizomes in lukewarm water for an hour before planting to rehydrate them, though this is not strictly necessary if the soil will be kept moist.
Step 2: Digging The Hole
Dig a hole that is about 3-4 inches deep. A good rule is to plant the rhizome at a depth roughly twice its height. Space holes 12-18 inches apart to give the plants room to spread.
Step 3: Positioning The Bulb
Place the rhizome in the hole with the growing points or eyes facing upward. If you’re unsure which side is up, plant the rhizome on its side; the shoots will find there way to the surface. This is a common technique used by many gardeners.
Step 4: Covering And Watering
Gently backfill the hole with soil, taking care not to damage the rhizome. Lightly tamp the soil down to remove large air pockets. Water the area thoroughly after planting to settle the soil and initiate growth. Keep the soil consistently moist but not soggy as the shoots emerge.
Caring For Calla Lilies After Planting
Consistent care after planting ensures healthy growth and prolific blooming.
Watering Requirements
Calla lilies need regular moisture, especially during their active growth and flowering period. Water deeply when the top inch of soil feels dry. Reduce watering once the flowers begin to fade and the leaves start to yellow in late summer or fall, as the plant prepares for dormancy.
Fertilizing For Healthy Blooms
Feed your calla lilies with a balanced, water-soluble fertilizer (like a 10-10-10 formula) every two to three weeks during the growing season. Alternatively, you can apply a slow-release fertilizer at planting time. Avoid high-nitrogen fertilizers, which promote leafy growth at the expense of flowers.
Mulching And Weed Control
Apply a 2-3 inch layer of organic mulch, such as bark chips or straw, around the plants. Mulch helps retain soil moisture, suppresses weeds, and keeps the root zone cool. Keep the mulch a few inches away from the base of the stems to prevent rot.
Growing Calla Lilies In Containers
Calla lilies adapt very well to container life, making them perfect for patios and small spaces. Choose a pot that is at least 10-12 inches in diameter and has excellent drainage holes. Use a quality potting mix and plant the rhizomes at the same depth as in the ground. Container-grown callas may need more frequent watering and feeding, as nutrients leach out faster.
Overwintering Calla Lily Bulbs
In regions colder than USDA zone 8, calla lily rhizomes must be lifted and stored indoors for the winter.
- After the first frost blackens the foliage, cut the stems back to about 2 inches.
- Carefully dig up the rhizomes, brushing off excess soil.
- Let them cure in a warm, dry, airy place for a few days.
- Store the dried rhizomes in a box or paper bag filled with slightly moist peat moss or vermiculite.
- Keep them in a cool (50-60°F), dark place until spring planting time arrives.
Troubleshooting Common Problems
Even with good care, issues can arise. Here are solutions to common problems.
Yellowing Leaves
Yellow leaves can signal overwatering, underwatering, or the natural dormancy process in fall. Assess your watering habits and check for proper drainage. If it’s autumn, yellowing is normal as the plant prepares to rest.
Lack Of Flowers
If your calla lily produces leaves but no flowers, possible causes include too much nitrogen fertilizer, insufficient sunlight, overcrowded rhizomes, or a lack of a dormant period. Ensure the plant gets enough light and review your fertilization routine.
Pests And Diseases
Calla lilies can be affected by aphids, spider mites, and bacterial soft rot. Inspect plants regularly. Treat pests with insecticidal soap or a strong spray of water. Prevent rot by ensuring excellent drainage and avoiding overwatering.
Propagating Calla Lilies
You can easily propagate calla lilies by dividing the rhizomes. The best time to do this is when you lift them for winter storage or in early spring before planting.
- Gently separate offsets or small rhizome sections from the main clump, ensuring each division has at least one growth eye.
- Allow the cut surfaces to dry and callus over for a day.
- Plant the divisions immediately or store them as you would mature rhizomes.
Frequently Asked Questions
How Deep Should I Plant Calla Lily Bulbs?
Plant calla lily rhizomes about 3 to 4 inches deep with the eyes facing upward. In containers, a depth of 3 inches is usually sufficient.
Can You Plant Calla Lily Bulbs In Pots?
Yes, calla lilies grow very well in pots. Use a large container with drainage holes and a well-draining potting mix. This method is ideal for colder climates where pots can be brought indoors in winter.
When Is The Best Time To Plant Calla Lily Rhizomes?
The best time is in spring after the threat of frost has passed and soil temperatures are above 60°F. In cold climates, you can start them indoors several weeks earlier.
Why Are My Calla Lily Bulbs Not Sprouting?
Failure to sprout can be due to planting too early in cold soil, rhizome rot from overly wet conditions, or using a non-viable rhizome. Ensure proper planting time, drainage, and start with healthy stock.
How Do You Store Calla Bulbs Over Winter?
After the foliage dies back, dig up the rhizomes, let them dry for a few days, and store them in a cool, dark place in slightly moist peat moss or vermiculite until spring.
Following these guidelines for how to plant calla lily bulbs will give you a strong foundation for success. With proper timing, site selection, and ongoing care, you can enjoy the sophisticated beauty of calla lily flowers in your garden for many seasons. Remember to adjust practices like watering as the plant moves through its growth cycle, and don’t forget the important dormant period for sustained health. Your efforts will be rewarded with striking, graceful blooms that add a touch of elegance to any setting.