Chocolate Cosmos vs Water Lily Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Chocolate Cosmos

Chocolate Cosmos

Cosmos atrosanguineus

VS
Water Lily

Water Lily

Nymphaea spp.

Chocolate Cosmos

Chocolate Cosmos

Cosmos atrosanguineus

Chocolate Cosmos is a tuberous perennial plant prized for its dark, velvety, chocolate-scented flowers. It typically grows to a height of 40-60 cm. The flowers are usually a deep maroon to chocolate brown color and bloom from summer to frost. While it can be grown in containers, it is primarily an outdoor plant that requires specific conditions to thrive. People grow it for its unique flower color, fragrance, and ornamental value in gardens.

Asteraceae Mexico (endemic to a small area in Mexico; now extinct in the wild)
✨ Features: Chocolate-scented flowers, unique dark color.
📖 Read Complete Chocolate Cosmos Guide
Water Lily

Water Lily

Nymphaea spp.

Water lilies are aquatic rhizomatous perennials known for their striking, floating leaves and beautiful, often fragrant flowers. They are naturally outdoor plants, thriving in ponds, lakes, and other still bodies of water. The large, circular leaves, called lily pads, provide shelter for aquatic life. People cultivate water lilies for their ornamental value, adding beauty and tranquility to water gardens. They come in a range of colors, including white, pink, yellow, and red. Attempts to grow them indoors are generally unsuccessful due to the need for a large water volume and intense sunlight.

Nymphaeaceae Worldwide, various species native to different regions
✨ Features: Beautiful flowers, provides habitat for aquatic life
📖 Read Complete Water Lily Guide

Quick Plant Comparison

Feature Chocolate Cosmos Water Lily
Light Full sun to partial shade. Requires at least 6 hours of direct sunlight for optimal flowering. Full sun (at least 6 hours of direct sunlight daily)
Watering Every 3-7 days during the growing season, depending on weather and soil drainage. Constantly submerged
Humidity 40-60% 70-100%
Temperature 18-24°C 20-30°C
Care Level Expert Expert
Growth Rate Moderate Moderate To Fast, Depending On The Species And Conditions; Can Be An Aggressive Spreader In Suitable Environments
Max Height 40-60 cm Leaves float on the water surface; flower stems can reach 15-30 cm above the water.
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil, such as a mix of potting soil, perlite, and sand. Heavy loam or clay soil amended with organic matter
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly 30 minutes weekly during growing season for pruning and fertilization.

🔬 Botanical Information — Comparing These Plants

Chocolate Cosmos

Scientific Name Cosmos atrosanguineus
Family Asteraceae
Native To Mexico (endemic to a small area in Mexico; now extinct in the wild)
Also Known As Chocolate Cosmos
Leaves The leaves are pinnately divided, resembling ferns, and are a medium green color. They are finely textured and provide a delicate backdrop to the dark flowers.
Flowers While it may flower indoors under ideal conditions (very bright light), it is more commonly and reliably flowered outdoors. The flowers are typically a deep maroon to chocolate brown color and have a velvety texture. They are approximately 3-5 cm in diameter and have a distinct chocolate scent.

Water Lily

Scientific Name Nymphaea spp.
Family Nymphaeaceae
Native To Worldwide, various species native to different regions
Also Known As Water Lily, Lily Pad
Leaves Large, circular, floating leaves (lily pads) that can range in size from a few inches to several feet in diameter, depending on the species. They are typically green but can have reddish or purplish hues.
Flowers Water lilies produce beautiful, cup-shaped flowers in a variety of colors, including white, pink, yellow, and red. They rarely flower indoors due to insufficient light and space.

📏 Size & Growth — Plant Comparison

Chocolate Cosmos

Height 40-60 cm
Spread 30-45 cm
Growth Rate Moderate
Growth Pattern The Chocolate Cosmos grows upright with slender stems and fern-like foliage. It produces flowers on long stalks that rise above the foliage.

Water Lily

Height Leaves float on the water surface; flower stems can reach 15-30 cm above the water.
Spread Can spread several feet wide via rhizomes, depending on the species and growing conditions.
Growth Rate Moderate To Fast, Depending On The Species And Conditions; Can Be An Aggressive Spreader In Suitable Environments
Growth Pattern Rhizomatous perennial with floating leaves and flowers that emerge from the water surface.

🌱 Propagation — Comparing Plant Growth

Chocolate Cosmos

Methods: Division, Tubers, Seed (though seed propagation can be challenging and may not produce true-to-type offspring)

Difficulty: Moderate

Tips: Divide tubers in early spring before new growth begins. Plant tubers in well-draining soil and keep moist until established. Seeds can be sown indoors 6-8 weeks before the last frost.

Water Lily

Methods: Division of rhizomes, seed

Difficulty: Moderate

Tips: Divide rhizomes in early spring before new growth begins. Plant rhizome sections in aquatic soil and submerge in water. Seeds can be collected from mature seed pods and sown in a warm, shallow water environment.

✨ Benefits & Features — Comparing Plant Value

Chocolate Cosmos

The Chocolate Cosmos is unique for its dark, velvety flowers and distinct chocolate scent. It is also notable for being extinct in the wild, with all cultivated plants being clones of a single specimen.

  • ✓ Aesthetic appeal with unique dark flowers.
  • ✓ Pleasant chocolate fragrance enhances outdoor spaces.
  • ✓ Attracts pollinators like bees and butterflies.
  • ✓ Provides cut flowers for arrangements.
  • ✓ Adds visual interest to garden borders and containers.
  • ⚠️ Toxic to pets

Water Lily

Water lilies are known for their stunning, floating flowers and large, circular leaves. They are adapted to aquatic environments and play an important role in pond ecosystems. Their flowers open and close daily, adding to their unique charm.

  • ✓ Adds beauty and tranquility to outdoor spaces.
  • ✓ Provides habitat for aquatic wildlife.
  • ✓ Attracts pollinators to the garden.
  • ✓ Offers a unique and visually appealing focal point.
  • ✓ Can help to oxygenate the water in a pond.
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Chocolate Cosmos

Repotting Not typically repotted frequently as it is usually grown outdoors. If grown in a container, repot every 2-3 years in spring.
Pruning Deadhead spent flowers to encourage further blooming. Cut back foliage in the fall after it has died back.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 2-4 weeks during the growing season.
Seasonal Care In summer, provide regular watering and fertilization. In fall, reduce watering as the plant prepares for dormancy. In winter, store tubers in a cool, dry place. In spring, replant tubers after the last frost.

Water Lily

Repotting Not applicable as they are grown in ponds or large containers; division of rhizomes may be necessary every few years to control spread.
Pruning Remove dead or yellowing leaves and spent flowers to encourage new growth and prevent disease.
Fertilizing Aquatic plant fertilizer tablets or granules, applied according to product instructions during the growing season (spring and summer)
Seasonal Care In winter, some water lily varieties may go dormant. In colder climates, the rhizomes may need to be moved to a frost-free location. In summer, ensure adequate sunlight and fertilization for optimal flowering.

🌞 Light Requirements

Chocolate Cosmos

Full sun to partial shade. Requires at least 6 hours of direct sunlight for optimal flowering.

Low light tolerant: ❌ No

Water Lily

Full sun (at least 6 hours of direct sunlight daily)

Low light tolerant: ❌ No

💧 Watering Needs

Chocolate Cosmos

Water regularly during the growing season, allowing the top inch of soil to dry out between waterings. Avoid overwatering, which can lead to tuber rot. Reduce watering in the fall as the plant prepares for dormancy. Signs of overwatering include yellowing leaves and a mushy stem base. Underwatering results in wilting and dry, crispy leaves.

Water Lily

Water lilies require constant submersion in water. The water level should be maintained to cover the rhizome and roots. Signs of underwatering are wilting or browning leaves, which is unlikely in a pond environment. Overwatering is not a concern as they are aquatic plants.

🌡️ Temperature & Humidity

Chocolate Cosmos

Temperature: 18-24°C

Humidity: 40-60%

Water Lily

Temperature: 20-30°C

Humidity: 70-100%

🤔 Which Plant Is Right For You?

Chocolate Cosmos

Chocolate Cosmos

Cosmos atrosanguineus
Care: Expert Time: 15 minutes weekly Beginner: No

Experienced gardeners who want a unique and fragrant addition to their outdoor garden.

✅ Choose This Plant If...

  • You love the unique chocolate scent of the flowers.
  • You want a plant with unusual dark-colored blooms.
  • You have a sunny garden or patio.
  • You enjoy a challenge and are willing to provide the specific care this plant needs.
  • You want to attract pollinators to your garden.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You don't have a sunny location.
  • You are a beginner gardener looking for an easy-care plant.
📍 Ideal Location: Sunny garden bed or patio container.
🎨 Style: Cottage, Romantic, Eclectic
🏠 Apartment Friendly: Limited
⚠️ Cosmos atrosanguineus contains compounds that can be toxic to dogs, cats, and horses. Symptoms may include gastrointestinal upset (vomiting, diarrhea), skin irritation, and allergic reactions. All parts of the plant are potentially toxic, but the tubers are the most concentrated source of toxins.
Water Lily

Water Lily

Nymphaea spp.
Care: Expert Time: 30 minutes weekly during growing season for pruning and fertilization. Beginner: No

Gardeners with ponds or water gardens seeking to add beauty and tranquility to their outdoor space.

✅ Choose This Plant If...

  • You have a pond or water garden and want to add beautiful, floating flowers.
  • You want to provide shelter and habitat for aquatic life.
  • You enjoy the calming and tranquil aesthetic of water features.
  • You are experienced with aquatic plant care and can provide the necessary conditions.
  • You want a plant that attracts pollinators to your garden.

❌ Skip This Plant If...

  • You do not have a pond or water garden.
  • You cannot provide the necessary full sun exposure.
  • You have pets that may ingest the plant.
  • You are looking for an easy-to-care-for indoor plant.
📍 Ideal Location: Outdoor pond or water garden with full sun exposure.
🎨 Style: Tropical, Traditional, Naturalistic
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Water Lilies contain glycosides that can be toxic to dogs, cats, and horses. Symptoms include drooling, vomiting, and diarrhea. All parts of the plant are considered toxic.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

🌿

Both plants have similar basic care requirements but differ in appearance and specific needs. Compare plants carefully to find the best fit for your space.

💡 Pro Tips For Comparing These Plants

Chocolate Cosmos Care Tips

Chocolate Cosmos is primarily an outdoor plant and requires specific conditions to thrive indoors. It needs ample sunlight, well-draining soil, and careful watering to prevent tuber rot. Indoor cultivation is challenging due to the high light requirements and the need for a cool, dry dormancy period in winter.

  • Provide at least 6 hours of direct sunlight daily for optimal flowering.
  • Ensure well-draining soil to prevent tuber rot.
  • Fertilize regularly during the growing season with a balanced liquid fertilizer.
  • Deadhead spent flowers to encourage more blooms.
  • Protect from frost in colder climates by lifting and storing tubers indoors.
❄️ Winter: In colder climates, the tubers need to be lifted and stored indoors over winter. Store them in a cool, dry place, such as a basement or garage. Reduce watering significantly during this period.
☀️ Summer: Provide regular watering and fertilization during the summer growing season. Ensure the plant receives adequate sunlight. Deadhead spent flowers to encourage continuous blooming.

Water Lily Care Tips

Water lilies are primarily outdoor plants requiring full sun and constant submersion in water. Indoor cultivation is extremely challenging due to the need for a large water volume, intense light, and temperature control. They are best suited for ponds and water gardens.

  • Provide at least 6 hours of direct sunlight daily.
  • Use aquatic plant fertilizer regularly during the growing season.
  • Remove dead or yellowing leaves promptly to prevent disease.
  • Control algae growth to ensure optimal water quality.
  • Protect rhizomes from freezing temperatures during winter in colder climates.
❄️ Winter: In colder climates, the rhizomes should be protected from freezing. This can be done by moving them to a frost-free location or sinking them to the deepest part of the pond where the water won't freeze solid.
☀️ Summer: Ensure adequate sunlight and fertilization during the summer months to promote flowering. Monitor for pests and diseases and take appropriate action.

⚠️ Common Problems & Solutions — Plant Care Comparison

Chocolate Cosmos

Common Issues: Tuber rot, Powdery mildew, Aphids, Lack of flowering
Solutions: Tuber rot: Ensure well-draining soil and avoid overwatering. Powdery mildew: Improve air circulation and treat with a fungicide. Aphids: Spray with insecticidal soap. Lack of flowering: Provide sufficient sunlight and fertilize regularly.

Water Lily

Common Issues: Algae growth, Aphids, Lily pad borer
Solutions: Control algae with appropriate algaecides or by introducing algae-eating fish or snails. Treat aphids with insecticidal soap. Remove lily pad borer larvae by hand or use appropriate insecticides safe for aquatic environments.

❓ Frequently Asked Questions — Comparing These Plants

Chocolate Cosmos

What are the light requirements for Chocolate Cosmos?

Chocolate Cosmos requires at least six hours of direct sunlight daily to thrive and produce abundant blooms. When grown indoors, place it near a sunny window, preferably south-facing. If natural light is insufficient, supplement with grow lights. Insufficient light can lead to leggy growth and reduced flowering. Rotate the plant regularly to ensure even light exposure on all sides. Plants grown in too much shade will produce fewer blooms and may become susceptible to fungal diseases. Monitor the plant’s foliage; pale or yellowish leaves can indicate insufficient light.

How do I care for Chocolate Cosmos?

Chocolate Cosmos thrives in well-draining soil and prefers full sun to partial shade. Water regularly, allowing the soil to dry slightly between waterings; avoid overwatering to prevent root rot. Fertilize every 2-4 weeks during the growing season with a balanced, water-soluble fertilizer, or one specifically formulated for blooming plants. Deadhead spent flowers to encourage continuous blooming. In colder climates, protect from frost or bring indoors during winter. Chocolate Cosmos benefits from consistent humidity, especially when grown indoors. Ensure good air circulation to prevent fungal diseases. Regularly check for pests and address them promptly. Prune back in late fall to encourage bushier growth the following season.

How do I propagate Chocolate Cosmos?

Chocolate Cosmos can be propagated by division or stem cuttings.

Water Lily

What are the light requirements for Water Lily?

Water Lilies are sun-worshippers and require a minimum of 6 hours of direct sunlight each day to thrive and produce abundant blooms. The more sunlight they receive, the more flowers they will produce. Insufficient sunlight can lead to leggy growth, reduced flowering, and overall poor health.

How do I care for Water Lily?

Water Lilies need at least 6 hours of direct sunlight daily to bloom profusely. Plant them in heavy clay soil or aquatic planting media in a wide, shallow container. Submerge the container in a pond or large tub, ensuring the crown of the plant is slightly below the water surface (adjust depth as the plant grows). Water should be clean and free of algae.

How do I propagate Water Lily?

Water Lilies can be propagated through division or by collecting and planting seeds. Division is the easiest method.

Last updated: May 2, 2026 — Plant care data reviewed and verified by our editorial team.