Growing Jack-in-the-Pulpit (Arisaema triphyllum) from dormant corms is a rewarding experience that allows you to cultivate this unique and fascinating native woodland perennial. Known for its distinctive hooded spathe that encloses a spadix, resembling a preacher in a pulpit, this plant is a jewel in any shady garden. While it can be grown from seed, starting with dormant corms offers a much faster path to blooming plants, often flowering within one to two years. This comprehensive guide will walk you through every step of the process, from sourcing your corms to ensuring their successful establishment and vibrant display.
Understanding Jack-in-the-Pulpit Corms
Before diving into the planting process, it’s essential to understand what Jack-in-the-Pulpit corms are and why they are the ideal starting point for propagation.
What are Corms?
A corm is a short, vertical, swollen underground plant stem that serves as a storage organ, much like a bulb. However, unlike bulbs which are made up of layers of fleshy leaves, corms are solid tissue. Jack-in-the-Pulpit corms are typically flattened and disc-shaped, often with a papery outer tunic. They contain stored food reserves that will fuel the initial growth of the plant when conditions are favorable.
Why Grow from Corms?
- Speed: Growing from corms is significantly faster than starting from seed. Seeds can take several years to mature into flowering-sized plants, requiring specific stratification and germination conditions. Corms, on the other hand, are already established plant structures ready to grow.
- Reliability: Sourcing healthy, dormant corms from reputable nurseries offers a high success rate for germination and growth, provided proper planting techniques are followed.
- Accessibility: While collecting from the wild is discouraged due to conservation concerns, many nurseries specialize in native plants and offer Jack-in-the-Pulpit corms for sale.
Key Differences: Corms vs. Bulbs vs. Tubers
It’s useful to distinguish corms from other underground storage organs:
| Feature | Corm | Bulb | Tuber |
|---|---|---|---|
| Structure | Solid, compressed stem tissue | Layers of fleshy leaves | Swollen stem or root |
| Origin | Enlarged basal stem | Modified leaves and stem | Modified stem or root |
| Examples | Jack-in-the-Pulpit, Gladiolus, Crocus | Tulip, Daffodil, Onion | Potato, Dahlia, Sweet Potato |
Sourcing Your Jack-in-the-Pulpit Corms
The quality and source of your corms are critical for success.
Where to Buy
- Reputable Native Plant Nurseries: These are your best bet for high-quality, ethically sourced corms. Look for nurseries that specialize in woodland plants or native species.
- Online Seed and Plant Retailers: Many online vendors offer Jack-in-the-Pulpit corms. Always check reviews and ensure they have a good reputation for providing healthy plant material.
- Avoid Wild Digging: It is crucial to never dig up Jack-in-the-Pulpit from its natural habitat. This practice is illegal in many areas and harms wild populations.
What to Look For
When purchasing dormant corms, inspect them carefully:
- Firmness: Corms should be firm to the touch, not soft, mushy, or dried out.
- Size: Larger corms generally indicate a more mature plant with a greater capacity for energy reserves, potentially leading to faster flowering.
- Absence of Mold or Rot: Inspect for any signs of fungal growth or decay. A healthy corm may have a papery outer tunic that can sometimes appear slightly dry, but the internal tissue should be solid.
- Presence of Eyes/Buds: Look for small buds or “eyes” on the surface of the corm. These are the points from which new shoots will emerge.
When to Buy
Dormant corms are typically available for purchase in the fall or early spring, coinciding with their natural dormancy period. Purchasing in the fall allows you to plant them for overwintering, giving them a head start in the spring. Early spring purchases are also viable, allowing for planting just before or as the soil begins to warm.
Preparing for Planting
Proper site selection and soil preparation are vital for the health and vigor of your Jack-in-the-Pulpit.
Site Selection: Mimicking the Native Habitat
Jack-in-the-Pulpit thrives in conditions that mimic its natural woodland environment.
- Shade: This is the most critical factor. Choose a location that receives dappled shade or partial shade throughout the day. Full sun will scorch the leaves, and deep shade may reduce flowering. Areas under deciduous trees that provide summer shade but allow spring sun are ideal.
- Moisture: They prefer consistently moist, but not waterlogged, soil. Avoid areas that tend to dry out quickly or remain perpetually soggy.
- Soil Type: Rich, well-draining, loamy soil is best. They appreciate organic matter.
Soil Preparation
Before planting, amend the soil to provide the optimal environment.
- Clear the Area: Remove any weeds, debris, or competing vegetation from the planting site.
- Incorporate Organic Matter: Mix in generous amounts of compost, well-rotted leaf mold, or other organic amendments. This will improve soil structure, fertility, and moisture retention. Aim for a soil that is loose and crumbly.
- Check Drainage: Dig a hole and fill it with water. If the water drains away within a few hours, your drainage is likely adequate. If it pools, you may need to improve drainage by adding more organic matter or planting in raised beds.
Planting Your Jack-in-the-Pulpit Corms
The planting process is straightforward, but attention to detail ensures success.
Depth and Spacing
- Depth: Plant corms approximately 3-4 inches deep. The top of the corm should be about 3-4 inches below the soil surface. Planting too shallow can lead to drying out, while planting too deep can hinder emergence.
- Spacing: Space corms 6-10 inches apart. This allows them enough room to grow and spread without overcrowding.
Orientation
This is a crucial step often overlooked. Jack-in-the-Pulpit corms have a distinct top and bottom.
- Top: The top of the corm usually has several small buds or “eyes” from which the new shoots will emerge. It might also appear slightly concave.
- Bottom: The bottom is typically where the roots will grow from. It may have remnants of the previous year’s root system.
If unsure, it’s best to plant them slightly on their side. The plant has a remarkable ability to orient itself correctly regardless of how it’s planted, but a slightly angled or flat placement is generally recommended to avoid water pooling on top.
Planting Steps
- Dig a Hole: Dig a hole to the appropriate depth (3-4 inches) and width (two to three times the width of the corm).
- Place the Corm: Gently place the corm into the hole with the budded side (top) facing upwards.
- Backfill: Fill the hole with the amended soil, gently firming it around the corm.
- Water Thoroughly: Water the area well after planting to settle the soil and eliminate air pockets.
Care and Maintenance
Once planted, your Jack-in-the-Pulpit corms will require minimal but essential care to thrive.
Watering
- Establishment: Water regularly after planting, especially during dry spells, to keep the soil consistently moist but not saturated.
- Ongoing: Once established, Jack-in-the-Pulpit is relatively drought-tolerant, but it will perform best with consistent moisture during its growing season (spring and early summer). Reduce watering as the foliage begins to yellow and die back in late summer.
Fertilizing
Jack-in-the-Pulpit does not require heavy fertilization, especially if planted in well-amended soil.
- Spring Top-dressing: A light top-dressing of compost or a balanced organic fertilizer in early spring as new growth emerges is usually sufficient.
- Avoid Over-fertilizing: Excessive nitrogen can lead to lush foliage at the expense of flowering and can make the plant more susceptible to pests and diseases.
Mulching
Mulching is highly beneficial for Jack-in-the-Pulpit.
- Benefits: A layer of organic mulch (such as shredded leaves, wood chips, or compost) around the base of the plant helps retain soil moisture, suppress weeds, regulate soil temperature, and slowly adds nutrients as it decomposes.
- Application: Apply a 2-3 inch layer of mulch, keeping it a few inches away from the immediate stem of the plant to prevent rot.
Pest and Disease Management
Jack-in-the-Pulpit is generally a robust plant with few pest or disease issues when grown in its preferred conditions.
- Common Pests: Slugs and snails can sometimes nibble on the leaves. Hand-picking them or using organic slug bait can help.
- Common Diseases: Fungal diseases are rare but can occur in overly wet or poorly drained conditions. Good air circulation and proper watering practices are the best preventative measures.
- Signs of Trouble: Yellowing leaves can indicate too much sun, too little water, or poor drainage. Watch for any unusual spots or wilting.
Winter Care
Jack-in-the-Pulpit is a hardy perennial and requires minimal winter protection.
- Dieback: The above-ground foliage will naturally die back in late summer or early fall. Do not cut it back immediately; allow it to yellow and wither naturally, as the plant is drawing nutrients back into the corm.
- Mulch: Once the ground begins to freeze, you can add an extra layer of mulch for added insulation, especially in colder climates.
Propagation and Division
As your Jack-in-the-Pulpit plant matures, it may produce offsets or “cormlets” around the main corm.
When to Divide
Division is best done when the plant is dormant, typically in the fall after the foliage has died back or in very early spring before new growth appears.
How to Divide
- Excavate: Carefully dig up the entire clump of corms.
- Separate: Gently break apart the main corm from any smaller cormlets. Cormlets can sometimes be a bit attached and may require a gentle twist or a small knife to separate.
- Replant: Replant the main corms and the detached cormlets immediately into prepared soil as described in the planting section. Cormlets may take longer to reach flowering size than mature corms.
Seed Propagation (for completeness)
While this guide focuses on corms, it’s worth noting that Jack-in-the-Pulpit can also be grown from seed. However, this is a much longer and more complex process.
- Collecting Seeds: Seeds are produced in clusters of bright red berries that ripen in late summer.
- Stratification: Seeds require a two-stage stratification process (cold, moist stratification) to break dormancy.
- Germination: Germination can take several months to over a year.
- Maturity: It can take 3-7 years for seedlings to mature into flowering plants.
Troubleshooting Common Issues
Even with careful planting, you might encounter a few challenges.
No Growth
- Reasons:
Planted too late in the season.
Corm was unhealthy or dried out.
Planted too deep or too shallow.
Incorrect orientation (though plants are resilient).
Poor soil conditions (lack of moisture, poor drainage).
- Solution: Be patient, especially in the first year. Ensure the planting site meets the plant’s needs. If it’s been a full growing season with no sign of life, the corm might have failed.
Small or Weak Growth
- Reasons:
Corm was small or immature.
Insufficient light (too much shade).
Inconsistent watering.
Poor soil fertility.
- Solution: Ensure adequate light and moisture. Amend soil with compost. It may take a few years for a smaller corm to reach full potential.
Yellowing Foliage Too Early
- Reasons:
Too much direct sun.
Drought stress.
Overwatering leading to root rot.
- Solution: Assess light conditions and adjust watering. Ensure good drainage.
Jack-in-the-Pulpit in the Garden Ecosystem
Beyond their aesthetic appeal, Jack-in-the-Pulpit plays a valuable role in the garden ecosystem.
- Pollinators: The unique flower structure attracts small flies and gnats that are responsible for pollination.
- Wildlife Food Source: The bright red berries are a food source for birds and small mammals in the fall.
- Native Plant Value: As a native plant, it supports local insect populations and contributes to biodiversity.
| Aspect | Details | Impact |
|---|---|---|
| Light Requirements | Partial to dappled shade | Prevents leaf scorch, promotes healthy growth |
| Soil Moisture | Consistently moist, well-draining | Prevents wilting and root rot |
| Soil Type | Rich, loamy, organic | Provides nutrients and good structure |
| Fertilization | Minimal, compost in spring | Supports growth without causing issues |
| Watering Frequency | Regular during growth, reduced in fall | Ensures plant health and dormancy preparation |
Conclusion: A Fascinating Addition to Your Shade Garden
Growing Jack-in-the-Pulpit from dormant corms is an accessible and enjoyable way to introduce this botanical wonder to your garden. By understanding the corm’s needs, preparing the right environment, and following these planting and care guidelines, you’ll be well on your way to enjoying the striking beauty and unique charm of this native woodland perennial. Patience is key, especially in the first year, but the reward of watching this fascinating plant emerge and flourish is truly worth the effort. Happy gardening!