Christmas Fern vs Cup Flower Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Christmas Fern
Polystichum acrostichoides
The Christmas fern is a robust, evergreen fern native to eastern North America. It gets its name from the fact that its fronds often remain green throughout the Christmas season. It features leathery, lance-shaped fronds that are deeply divided into leaflets (pinnae). The fertile fronds have spore-bearing sori on the upper pinnae. It typically grows in moist, shaded woodlands and is a popular choice for naturalistic gardens. While it can be grown indoors, it requires specific conditions and is generally better suited for outdoor environments.
Cup Flower
Cobaea scandens
Cobaea scandens, commonly known as Cup Flower or Cup-and-Saucer Vine, is a vigorous, fast-growing perennial vine often grown as an annual in temperate climates. It is characterized by its climbing habit, using tendrils to attach to supports. The plant produces unique, bell-shaped flowers that start green and mature to a deep purple or white, resembling cups sitting on saucers. It is primarily an outdoor plant, valued for its rapid growth and ability to cover fences, trellises, and walls quickly. While occasionally grown indoors, it requires significant space and light to thrive.
Quick Plant Comparison
| Feature | Christmas Fern | Cup Flower |
|---|---|---|
| Light | Partial to full shade. Avoid direct sunlight, especially indoors. | Full sun to partial shade outdoors. Indoors, requires very bright, direct light for several hours daily. |
| Watering | Every 7-10 days, adjust based on humidity and temperature. | Outdoors: Every 2-3 days in hot weather, less frequently in cooler weather. Indoors: Every 7-10 days, depending on light and humidity. |
| Humidity | 50-70% | 40-60% |
| Temperature | 10-21°C | 18-27°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Fast |
| Max Height | 30-60 cm | Outdoors: 6-12 meters. Indoors: 1-3 meters (highly dependent on support and pruning). |
| Pet Safety | ✅ Safe | ✅ Safe |
| Soil | Well-draining, humus-rich soil. A mix of potting soil, peat moss, and perlite is suitable. | Well-draining, fertile soil. A mix of potting soil, perlite, and compost is suitable. |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 10 minutes weekly | 30 minutes weekly (pruning, watering, fertilizing). |
🔬 Botanical Information — Comparing These Plants
Christmas Fern
| Scientific Name | Polystichum acrostichoides |
|---|---|
| Family | Dryopteridaceae |
| Native To | Eastern North America |
| Also Known As | Christmas Fern, Evergreen Wood Fern |
| Leaves | The fronds are lance-shaped, 30-90 cm long, and deeply divided into leathery, dark green pinnae. The pinnae are slightly sickle-shaped and have a toothed margin. The fertile fronds have smaller, spore-bearing pinnae at the tip. |
| Flowers | Ferns do not produce flowers. They reproduce via spores. |
Cup Flower
| Scientific Name | Cobaea scandens |
|---|---|
| Family | Polemoniaceae |
| Native To | Mexico, Central America |
| Also Known As | Cup-and-Saucer Vine, Cathedral Bells, Mexican Ivy, Monastery Bells |
| Leaves | The leaves are pinnately compound, with 4-6 leaflets and a terminal tendril. The leaflets are ovate to elliptic, with a smooth margin and a dark green color. They are typically 5-10 cm long. |
| Flowers | It can flower indoors with sufficient light, but flowering is more prolific outdoors. The flowers are bell-shaped, about 5-7 cm in diameter, and start green before turning purple or white. They have a distinctive cup-and-saucer shape. |
📏 Size & Growth — Plant Comparison
Christmas Fern
Cup Flower
🌱 Propagation — Comparing Plant Growth
Christmas Fern
Methods: Division, Spores
Difficulty: Moderate
Tips: Division is best done in early spring. Carefully separate the rhizomes and replant. Spore propagation is more challenging and requires a sterile environment.
Cup Flower
Methods: Seed, Stem cuttings
Difficulty: Moderate
Tips: For seeds, scarify the seed coat before sowing to improve germination. For stem cuttings, take semi-hardwood cuttings in late summer and root them in a well-draining medium.
✨ Benefits & Features — Comparing Plant Value
Christmas Fern
The Christmas fern is distinguished by its evergreen foliage and the presence of sori only on the upper pinnae of fertile fronds. This unique characteristic makes it easy to identify.
- ✓ Provides year-round greenery in shaded areas.
- ✓ Helps prevent soil erosion.
- ✓ Attracts beneficial insects.
- ✓ Low maintenance once established.
- ✓ Adds a natural, woodland aesthetic.
- 🐾 Pet Safe
Cup Flower
The cup-shaped flowers are its most distinctive feature, with their unique shape and color-changing properties. Its rapid growth rate allows it to quickly cover large areas, making it a popular choice for creating privacy screens or adding vertical interest to gardens.
- ✓ Provides quick coverage for fences and walls
- ✓ Attracts pollinators like bees and hummingbirds
- ✓ Adds a unique and exotic touch to the garden
- ✓ Offers a visually appealing display with its cup-shaped flowers
- ✓ Can be grown in containers, allowing for flexibility in placement
- 🐾 Pet Safe
📅 Maintenance Schedule — Plant Care Comparison
Christmas Fern
Cup Flower
🌞 Light Requirements
Christmas Fern
Partial to full shade. Avoid direct sunlight, especially indoors.
Low light tolerant: ❌ No
Cup Flower
Full sun to partial shade outdoors. Indoors, requires very bright, direct light for several hours daily.
Low light tolerant: ❌ No
💧 Watering Needs
Christmas Fern
Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Allow excess water to drain away. Signs of overwatering include yellowing or browning fronds. Signs of underwatering include wilting or crispy fronds.
Cup Flower
Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Ensure good drainage. Indoors, allow the soil to dry out slightly between waterings. Signs of underwatering include wilting leaves; overwatering includes yellowing leaves and soggy soil.
🌡️ Temperature & Humidity
Christmas Fern
Temperature: 10-21°C
Humidity: 50-70%
Cup Flower
Temperature: 18-27°C
Humidity: 40-60%
🤔 Which Plant Is Right For You?
Christmas Fern
Polystichum acrostichoidesExperienced gardeners seeking a low-maintenance, evergreen groundcover for shaded areas.
✅ Choose This Plant If...
- You want an evergreen fern for a shady garden area.
- You need a plant for erosion control on a slope.
- You want to attract beneficial insects to your garden.
- You appreciate low-maintenance plants once established.
- You have a woodland garden and want a native species.
❌ Skip This Plant If...
- You have limited space indoors.
- You cannot provide high humidity.
- You are a beginner gardener looking for an easy indoor plant.
Cup Flower
Cobaea scandensGardeners with ample outdoor space looking for a fast-growing vine to cover structures.
✅ Choose This Plant If...
- You want a fast-growing vine to quickly cover a fence or trellis.
- You are looking for a plant with unique and interesting flowers.
- You want to attract pollinators to your garden.
- You have a sunny outdoor space where the vine can thrive.
- You enjoy a challenge and are willing to provide the specific care needed for indoor growth.
❌ Skip This Plant If...
- You have limited indoor space and cannot provide ample light.
- You are looking for a low-maintenance indoor plant.
- You live in a climate with harsh winters and don't want to overwinter the plant indoors.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Christmas Fern has moderate growth, while Cup Flower grows fast.
💡 Pro Tips For Comparing These Plants
Christmas Fern Care Tips
Christmas fern is primarily an outdoor plant that prefers moist, shaded environments. Indoor cultivation is challenging due to the need for high humidity, cool temperatures, and indirect light. It requires consistent moisture and well-draining soil. It is not a good choice for beginners indoors.
- Provide consistent moisture, especially during dry periods.
- Mulch around the base of the plant to retain moisture.
- Avoid planting in direct sunlight.
- Divide clumps every few years to maintain vigor.
- Monitor for pests and diseases regularly.
Cup Flower Care Tips
Cobaea scandens is primarily an outdoor plant. Growing it indoors is challenging due to its high light requirements and vigorous growth. It needs ample space, strong support, and regular pruning to manage its size. Providing adequate light is crucial for flowering indoors.
- Provide a strong support structure for the vine to climb.
- Water deeply but infrequently, allowing the soil to dry slightly between waterings.
- Fertilize regularly during the growing season to promote vigorous growth and flowering.
- Prune regularly to control size and shape, especially indoors.
- Monitor for pests and diseases and treat promptly.
⚠️ Common Problems & Solutions — Plant Care Comparison
Christmas Fern
Cup Flower
❓ Frequently Asked Questions — Comparing These Plants
Christmas Fern
What are the light requirements for Christmas Fern?
Christmas Ferns prefer bright, indirect light. Direct sunlight can scorch their delicate fronds, leading to browning and damage. The ideal location is near a north-facing window, or in a room with filtered sunlight. If you notice the fronds turning pale green or yellow, it may indicate that the plant is receiving too much light. Conversely, if the fronds appear dark green and growth is slow, the plant may not be getting enough light. Avoid placing the fern in direct sunlight, especially during the hottest part of the day. Artificial light can also be used to supplement natural light, especially during the winter months.
How do I care for Christmas Fern?
Christmas Fern thrives in indirect light and requires consistent moisture. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain high humidity, ideally above 50%, through misting or using a humidifier. Plant in well-draining, slightly acidic potting mix rich in organic matter. Fertilize sparingly during the growing season (spring and summer) with a diluted balanced liquid fertilizer. Avoid direct sunlight, which can scorch the fronds. Prune away any dead or damaged fronds to maintain its appearance. Repot every 1-2 years, or when the plant becomes root-bound, into a slightly larger pot. Protect from drafts and sudden temperature changes. Monitor for pests like scale, and treat promptly if necessary.
How do I propagate Christmas Fern?
Christmas Ferns can be propagated by division or by spores. For division, carefully separate the rhizomes in spring, ensuring each division has healthy roots and fronds. Plant the divisions in well-draining potting mix and keep them moist. For spore propagation, collect spores from mature fronds and sow them on a sterile substrate. Keep the substrate moist and humid. Spore propagation is a slow process, often taking several months to produce small plantlets. Division is the easier and more common method for home gardeners. Ensure the parent plant is healthy before attempting propagation. New plants will require consistent moisture and high humidity.
Cup Flower
What are the light requirements for Cup Flower?
Cup Flower requires bright, indirect light to thrive and produce abundant blooms. A location near an east- or west-facing window is ideal, providing several hours of gentle morning or afternoon sun. Avoid placing the plant in direct, intense sunlight, which can scorch the leaves. If growing indoors, supplement natural light with a grow light if necessary, especially during the winter months. Insufficient light can result in leggy growth, fewer blooms, and pale foliage. Rotate the plant regularly to ensure even light exposure on all sides. When growing outdoors, choose a spot that receives full sun for at least 6 hours a day, but with some protection from the harshest midday rays, especially in hotter climates.
How do I care for Cup Flower?
Cup Flower thrives with consistent care. Provide bright, indirect light, avoiding harsh direct sunlight. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Fertilize regularly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength, focusing on formulas higher in phosphorus to promote blooming. Maintain moderate humidity levels, especially indoors, by misting or using a humidifier. Prune spent flowers to encourage continuous blooming. Repot in spring every 1-2 years into a slightly larger pot with well-draining potting mix. Monitor for pests like aphids and spider mites, treating promptly with insecticidal soap or neem oil. Provide temperatures between 60-75°F (15-24°C) for optimal growth. Reduce watering and fertilization in the fall and winter as growth slows. Ensure good air circulation to prevent fungal diseases.
How do I propagate Cup Flower?
Cup Flower can be propagated through stem cuttings, division, and, less commonly, from keiki (small plantlets that grow on the parent plant). For stem cuttings, take 4-6 inch cuttings from healthy stems, remove the lower leaves, and dip the cut end in rooting hormone. Plant the cuttings in moist potting mix and cover with a plastic bag to maintain humidity. Keep in a warm, bright location until roots develop (usually 4-6 weeks). For division, carefully separate the root ball of a mature plant into smaller sections, ensuring each section has healthy roots and stems. Replant the divisions in separate pots. Keiki propagation is rare, but if keiki develop, allow them to grow until they have roots, then carefully remove them and plant in their own pots.
Last updated: May 7, 2026 — Plant care data reviewed and verified by our editorial team.