Massachusetts gardeners should plant calla lilies after the last frost date, typically around mid-May. The best time to plant calla lily in massachusetts is when soil temperatures reach at least 60°F and all danger of frost has passed. Getting the timing right is the single most important step for growing these elegant flowers successfully in New England’s unpredictable climate.
Calla lilies (Zantedeschia) are not true lilies but rather rhizomatous plants native to South Africa. They thrive in warm conditions and cannot tolerate frost. In Massachusetts, where spring can be fickle, planting too early means risking rot or freeze damage. Planting too late shortens the blooming window before fall frosts arrive.
Understanding Massachusetts Growing Zones
Massachusetts spans USDA hardiness zones 5a to 7b. Your specific location within the state affects the ideal planting window. Coastal areas like Boston and Cape Cod warm up faster than inland regions like the Berkshires or Worcester County.
Zone 5 Areas (Western Mass And Higher Elevations)
These regions experience later last frost dates, often into late May. The soil stays cooler longer. You should wait until late May or even early June to plant calla lilies here.
Zone 6 Areas (Central Mass And Most Suburbs)
Most of Massachusetts falls into zone 6. The average last frost date is around May 15. Mid-May to late May is the sweet spot for planting calla lilies in these areas.
Zone 7 Areas (Coastal And Southern Mass)
Coastal areas like Martha’s Vineyard and Nantucket enjoy milder springs. You can plant calla lilies as early as early May, but always check the 10-day forecast for late frosts.
Best Time To Plant Calla Lily In Massachusetts
The exact timing depends on three factors: soil temperature, air temperature, and frost risk. Here is the step-by-step approach to determine your perfect planting date.
Check Soil Temperature First
Calla lilies need soil temperatures consistently above 60°F. Cold, wet soil causes rhizomes to rot. Use a soil thermometer inserted 4 inches deep. Take readings in the morning for three consecutive days. When all three readings are above 60°F, you are ready.
Monitor The 10-Day Forecast
Even after the average last frost date, a surprise frost can occur. Do not plant if the forecast shows nighttime temperatures dropping below 50°F. If a late frost threatens after planting, cover your calla lilies with frost cloth or bring containers indoors.
Consider Microclimates In Your Garden
South-facing slopes and areas near buildings warm up faster. North-facing spots and low-lying areas stay cooler longer. Plant in the warmest part of your garden for best results. Raised beds also warm up earlier than ground soil.
Preparing Your Calla Lily Rhizomes For Planting
Before you put rhizomes in the ground, take these steps to ensure strong growth. Proper preparation makes a big difference in how well your calla lilies establish.
Select Healthy Rhizomes
Choose firm, plump rhizomes with no soft spots or mold. Larger rhizomes produce bigger plants and more flowers. Avoid any that feel mushy or look shriveled.
Pre-Sprout Indoors (Optional But Helpful)
For an earlier bloom, start rhizomes indoors 4-6 weeks before your planting date. Plant each rhizome in a 6-inch pot with well-draining potting mix. Keep them in a bright, warm spot (65-70°F). Water sparingly until growth appears. This gives you a head start on the short Massachusetts growing season.
Soak Rhizomes Before Planting
Soak your rhizomes in room-temperature water for 1-2 hours before planting. This rehydrates them and encourages faster root development. Do not soak longer than 2 hours or they may rot.
Step-By-Step Planting Guide
Follow these steps for successful calla lily planting in Massachusetts soil. Each step builds on the last for optimal results.
- Choose a sunny location. Calla lilies need at least 6 hours of direct sunlight daily. Morning sun with afternoon shade works well in hotter areas.
- Amend the soil. Mix in 2-3 inches of compost or well-rotted manure. Calla lilies prefer rich, organic soil that drains well. If your soil is heavy clay, add sand or perlite to improve drainage.
- Dig holes 4 inches deep. Space holes 12-18 inches apart for good air circulation. Closer spacing works for container planting.
- Place rhizomes with eyes facing up. The pointed end or small buds should face upward. Cover with 2 inches of soil initially. As shoots emerge, add more soil to fill the hole.
- Water thoroughly after planting. Give each rhizome a good soak to settle the soil. Then water sparingly until growth appears to avoid rot.
- Apply a thin layer of mulch. Use 1-2 inches of organic mulch like shredded bark or straw. This keeps soil temperature stable and retains moisture.
- Mark the planting spot. Use plant markers or stakes so you remember where you planted. This helps avoid accidental digging later.
Caring For Calla Lilies After Planting
Once your calla lilies are in the ground, proper care ensures they thrive through the Massachusetts summer. Consistent attention pays off with beautiful blooms.
Watering Schedule
Calla lilies like consistent moisture but not soggy soil. Water deeply once or twice a week, depending on rainfall. Let the top inch of soil dry between waterings. During hot spells, increase watering frequency. Mulch helps retain moisture and reduces watering needs.
Fertilizing For Blooms
Feed calla lilies every 4-6 weeks during the growing season. Use a balanced, water-soluble fertilizer like 10-10-10. Switch to a bloom-boosting formula (higher phosphorus) once flower buds appear. Stop fertilizing in late August to let plants prepare for dormancy.
Deadheading Spent Flowers
Remove faded flowers promptly to encourage more blooms. Cut the flower stem back to the base of the plant. Leave the foliage intact until it yellows naturally. The leaves gather energy for next year’s growth.
Pest And Disease Management
Watch for slugs and snails, which love calla lily foliage. Use beer traps or diatomaceous earth around plants. Aphids can appear on new growth; spray them off with water or use insecticidal soap. Root rot is the biggest risk, so avoid overwatering.
Growing Calla Lilies In Containers
Container gardening offers flexibility for Massachusetts gardeners. You can move pots to catch sun or avoid frost. This method works especially well for those with limited garden space.
- Choose pots at least 12 inches wide with drainage holes.
- Use high-quality potting mix, not garden soil.
- Plant rhizomes 2-3 inches deep, one per 12-inch pot or three per 18-inch pot.
- Place containers in full sun to partial shade.
- Water more frequently than in-ground plants, as pots dry out faster.
- Bring containers indoors before the first fall frost to extend the growing season.
Extending The Blooming Season
Massachusetts summers are short, but you can maximize bloom time with a few strategies. Calla lilies typically bloom from July to September with proper care.
Stagger Planting Dates
Plant some rhizomes in mid-May, then another batch in early June. This spreads out the bloom period. Late-planted calla lilies will flower later in the season.
Use Early-Blooming Varieties
Some calla lily cultivars flower earlier than others. Look for varieties labeled as early bloomers. ‘Crystal Blush’ and ‘Flame’ are known for earlier flowering.
Provide Afternoon Shade
In hot summers, afternoon shade keeps flowers from fading quickly. This extends the life of each individual bloom. Morning sun with afternoon shade is ideal.
Overwintering Calla Lilies In Massachusetts
Calla lilies are not winter-hardy in Massachusetts. You must dig them up before the first hard frost. Proper storage ensures they survive until next spring.
When To Dig Up Rhizomes
Wait until after the first light frost kills the foliage, usually in October. Do not wait until a hard freeze. Cut back the dead leaves to 2 inches above the rhizome.
How To Store Rhizomes
Dig carefully with a garden fork to avoid damaging rhizomes. Brush off excess soil but do not wash them. Let them dry in a warm, airy spot for 1-2 weeks. Then store in a box with peat moss or vermiculite. Keep in a cool, dark place around 50-55°F. Check monthly for rot or shriveling.
Alternative: Grow As Annuals
Some gardeners treat calla lilies as annuals, replanting each year. This saves storage effort but costs more. If you have a warm basement or garage, overwintering is easy and economical.
Common Mistakes To Avoid
Even experienced gardeners make errors with calla lilies. Avoid these pitfalls for better results in Massachusetts.
- Planting too early. Cold soil kills rhizomes. Wait for consistent 60°F soil temperature.
- Overwatering after planting. Rhizomes rot easily in wet soil. Water sparingly until growth appears.
- Planting too deep. Rhizomes need to be 2-4 inches deep. Deeper planting delays emergence.
- Ignoring drainage. Calla lilies hate wet feet. Improve drainage or use raised beds.
- Forgetting to dig up in fall. Frozen rhizomes will not survive Massachusetts winters.
- Storing rhizomes too wet. Dry storage prevents mold and rot.
Frequently Asked Questions
Can I plant calla lilies in Massachusetts in April?
Only if you live in a coastal zone 7 area and the soil is warm. Most of Massachusetts should wait until mid-May or later. April planting risks frost damage and rot.
How late can I plant calla lilies in Massachusetts?
You can plant as late as early July and still get blooms before fall frost. Later planting means a shorter bloom period. For best results, plant by mid-June.
Do calla lilies need full sun in Massachusetts?
They need at least 6 hours of sun daily. Morning sun with afternoon shade works well, especially in hotter inland areas. Too much shade reduces flowering.
Should I soak calla lily bulbs before planting in Massachusetts?
Yes, soaking for 1-2 hours helps rehydrate them. Do not soak longer than 2 hours. This step is especially helpful if your rhizomes seem dry.
Can I leave calla lilies in the ground over winter in Massachusetts?
No. Calla lilies are not hardy enough for Massachusetts winters. You must dig them up and store them indoors. Leaving them in the ground will kill them.
Final Tips For Massachusetts Gardeners
Growing calla lilies in Massachusetts requires attention to timing and care. The key is patience. Wait for warm soil and frost-free nights. Provide consistent moisture and rich soil. Dig them up before winter arrives.
With the right approach, you can enjoy these elegant flowers from mid-summer through early fall. Their trumpet-shaped blooms add sophistication to garden beds, borders, and containers. The effort of proper planting and overwintering is well worth the reward.
Remember that each growing season is different. Keep a garden journal to track your planting dates and results. Over time, you will learn the best timing for your specific microclimate. Happy gardening in Massachusetts.