Cosmos vs Natal Plum Plant Comparison

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

Cosmos

Cosmos

Cosmos bipinnatus

VS
Natal Plum

Natal Plum

Carissa macrocarpa

Cosmos

Cosmos

Cosmos bipinnatus

Cosmos bipinnatus is an annual flowering plant typically grown outdoors. It features delicate, fern-like foliage and daisy-like flowers in shades of pink, purple, white, and occasionally yellow or orange. Plants typically reach heights of 1 to 6 feet. Cosmos are popular for their long blooming season, attracting pollinators like bees and butterflies. They are primarily grown for ornamental purposes in gardens and meadows, adding color and texture to landscapes. While relatively easy to grow outdoors, they are not well-suited for indoor cultivation due to their high light requirements and large size.

Asteraceae Mexico
✨ Features: Attracts pollinators, long blooming season, cut flowers
📖 Read Complete Cosmos Guide
Natal Plum

Natal Plum

Carissa macrocarpa

Carissa macrocarpa, or Natal Plum, is a dense, evergreen shrub or small tree known for its glossy, dark green leaves and fragrant, star-shaped white flowers. It produces edible, plum-like red fruits that are rich in vitamin C. While it can be grown in containers, it's primarily an outdoor plant, thriving in warm climates. People grow it for its ornamental value, edible fruit, and use as a security hedge due to its thorny branches. It's not ideally suited as an indoor plant due to high light requirements and potential size.

Apocynaceae South Africa
✨ Features: Edible fruit (when ripe), fragrant flowers, thorny branches provide a natural barrier.
📖 Read Complete Natal Plum Guide

Quick Plant Comparison

Feature Cosmos Natal Plum
Light Full sun (at least 6-8 hours of direct sunlight daily) Full sun to partial shade. Requires at least 6 hours of direct sunlight daily to thrive and produce fruit.
Watering Every 1-2 weeks, depending on weather and soil drainage Every 7-14 days, depending on environmental conditions and pot size.
Humidity 30-50% 40-60%
Temperature 18-27°C 18-27°C
Care Level Expert Expert
Growth Rate Fast Moderate
Max Height N/A (Outdoor plant, unsuitable for indoor growing) Indoors: Rarely exceeds 1-2 meters. Outdoors: Up to 4 meters.
Pet Safety ✅ Safe ❌ Toxic To Pets
Soil Well-draining soil; sandy or loamy soil is ideal Well-draining soil mix, such as a combination of potting soil, perlite, and sand.
Beginner Friendly ✅ Yes ❌ No
Weekly Maintenance 5 minutes weekly 30 minutes weekly (including watering, pruning, and pest control)

🔬 Botanical Information — Comparing These Plants

Cosmos

Scientific Name Cosmos bipinnatus
Family Asteraceae
Native To Mexico
Also Known As Cosmos, Garden Cosmos, Mexican Aster
Leaves The leaves of Cosmos bipinnatus are finely divided and fern-like, giving the plant a delicate and airy appearance. They are typically green in color and arranged oppositely along the stems. The leaves are relatively small, adding to the plant's overall graceful form.
Flowers Cosmos rarely, if ever, flower indoors due to insufficient light. Outdoors, they produce daisy-like flowers with a central disc and ray florets in shades of pink, purple, white, and occasionally yellow or orange. The flowers are typically 2-4 inches in diameter and bloom profusely throughout the summer and fall.

Natal Plum

Scientific Name Carissa macrocarpa
Family Apocynaceae
Native To South Africa
Also Known As Natal Plum, Large Num-Num
Leaves The leaves are glossy, dark green, and oval-shaped, measuring 2-5 cm in length. They are arranged oppositely on the stems and have a leathery texture.
Flowers Natal Plum produces fragrant, star-shaped white flowers in spring and summer. While it can flower indoors with sufficient light, fruit production is less common.

📏 Size & Growth — Plant Comparison

Cosmos

Height N/A (Outdoor plant, unsuitable for indoor growing)
Spread N/A (Outdoor plant, unsuitable for indoor growing)
Growth Rate Fast
Growth Pattern Cosmos grow upright with branching stems. They can reach heights of 1 to 6 feet, depending on the variety. The plants produce numerous flowers on long stems, making them excellent for cutting.

Natal Plum

Height Indoors: Rarely exceeds 1-2 meters. Outdoors: Up to 4 meters.
Spread Indoors: 1-1.5 meters. Outdoors: Up to 3 meters.
Growth Rate Moderate
Growth Pattern Natal Plum grows as a dense, multi-stemmed shrub or small tree. It can be pruned into a hedge or allowed to grow naturally. Its growth is relatively upright but can spread with age.

🌱 Propagation — Comparing Plant Growth

Cosmos

Methods: Seed

Difficulty: Easy

Tips: Sow seeds directly into the garden after the last frost or start indoors 4-6 weeks before the last frost. Lightly cover seeds with soil and keep moist until germination.

Natal Plum

Methods: Stem cuttings, Seed

Difficulty: Moderate

Tips: Take semi-hardwood cuttings in spring or summer. Dip the cut end in rooting hormone and plant in a well-draining potting mix. Keep the soil moist and provide warmth and humidity.

✨ Benefits & Features — Comparing Plant Value

Cosmos

Cosmos are known for their delicate, fern-like foliage and daisy-like flowers that come in a variety of colors. They are also highly attractive to pollinators, making them a valuable addition to any garden. Their long blooming season provides continuous color throughout the summer and fall.

  • ✓ Attracts pollinators to your garden.
  • ✓ Provides beautiful cut flowers.
  • ✓ Adds vibrant color to your outdoor space.
  • ✓ Easy to grow and maintain.
  • ✓ Supports local ecosystems.
  • 🐾 Pet Safe

Natal Plum

The Natal Plum is unique for its combination of fragrant flowers, edible fruit, and thorny branches. Its drought tolerance makes it a suitable choice for xeriscaping.

  • ✓ Provides edible fruit rich in Vitamin C
  • ✓ Offers fragrant flowers that attract pollinators
  • ✓ Acts as a natural security barrier due to its thorns
  • ✓ Adds an ornamental touch to gardens with its glossy foliage
  • ✓ Can be used in traditional medicine (with caution and expert knowledge)
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Cosmos

Repotting N/A (Outdoor plant)
Pruning Deadheading spent flowers
Fertilizing Balanced fertilizer (10-10-10) at half strength every 4-6 weeks during the growing season
Seasonal Care Deadhead spent flowers to encourage continued blooming. In colder climates, cosmos are grown as annuals and will die with the first frost.

Natal Plum

Repotting Repot every 2-3 years, or when the plant becomes root-bound.
Pruning Prune regularly to maintain shape and size, and to remove dead or damaged branches. Prune after flowering to encourage new growth.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 2-3 months during the growing season (spring and summer).
Seasonal Care In winter, reduce watering and protect from frost if grown in containers. In summer, ensure adequate sunlight and water during hot periods.

🌞 Light Requirements

Cosmos

Full sun (at least 6-8 hours of direct sunlight daily)

Low light tolerant: ❌ No

Natal Plum

Full sun to partial shade. Requires at least 6 hours of direct sunlight daily to thrive and produce fruit.

Low light tolerant: ❌ No

💧 Watering Needs

Cosmos

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Cosmos are relatively drought-tolerant once established. Signs of underwatering include wilting and drooping leaves. Overwatering can cause yellowing leaves and stem rot.

Natal Plum

Water deeply when the top inch of soil is dry. Avoid overwatering, which can lead to root rot. Allow the soil to dry slightly between waterings. Signs of underwatering include wilting leaves; overwatering includes yellowing leaves and soggy soil.

🌡️ Temperature & Humidity

Cosmos

Temperature: 18-27°C

Humidity: 30-50%

Natal Plum

Temperature: 18-27°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Cosmos

Cosmos

Cosmos bipinnatus
Care: Expert Time: 5 minutes weekly Beginner: Yes

Gardeners looking for easy-to-grow, colorful annuals that attract pollinators.

✅ Choose This Plant If...

  • You want a low-maintenance plant for your garden.
  • You want to attract butterflies and bees to your yard.
  • You need a plant that blooms for a long period.
  • You want to add vibrant colors to your outdoor space.
  • You want easy-to-grow cut flowers.

❌ Skip This Plant If...

  • You don't have a sunny outdoor space.
  • You want a plant that thrives indoors.
  • You live in a very cold climate with a short growing season.
📍 Ideal Location: Outdoor garden, meadow, or container garden in a sunny location
🎨 Style: Cottage, Bohemian, Naturalistic
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Cosmos bipinnatus is not toxic to dogs, cats, or horses.
Natal Plum

Natal Plum

Carissa macrocarpa
Care: Expert Time: 30 minutes weekly (including watering, pruning, and pest control) Beginner: No

Experienced gardeners in warm climates who want an ornamental shrub with edible fruit, and who can ensure it is kept away from pets.

✅ Choose This Plant If...

  • You live in a warm climate with plenty of sunshine.
  • You want an ornamental shrub with fragrant flowers and edible fruit.
  • You need a natural barrier or security hedge.
  • You are an experienced gardener looking for a new challenge.
  • You are willing to provide the specific care this plant needs.

❌ Skip This Plant If...

  • You have pets or small children due to the plant's toxicity.
  • You live in a cold climate with limited sunlight.
  • You are a beginner gardener.
  • You don't have space for a large shrub.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Outdoors in a sunny location. If attempting indoors, a south-facing window with supplemental lighting is necessary.
🎨 Style: Mediterranean, Coastal, Tropical
🏠 Apartment Friendly: No
⚠️ All parts of the plant except the ripe fruit are considered toxic. Contains cardiac glycosides. Symptoms in pets include vomiting, diarrhea, weakness, and potentially more severe cardiac issues. Toxic to dogs, cats, and horses.

🎯 Quick Verdict

Best for Beginners Cosmos
Pet Friendly Cosmos ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

📈

Cosmos has fast growth, while Natal Plum grows moderate.

💡 Pro Tips For Comparing These Plants

Cosmos Care Tips

Cosmos are easy to grow outdoors in full sun and well-draining soil. They are not suitable for indoor growing due to their high light requirements and large size. Attempting to grow them indoors will likely result in leggy, weak plants with few flowers.

  • Deadhead spent flowers regularly to encourage more blooms.
  • Provide support for taller varieties to prevent them from flopping over.
  • Water deeply but infrequently, allowing the soil to dry out slightly between waterings.
  • Avoid over-fertilizing, as this can lead to excessive foliage growth and fewer flowers.
  • Plant in well-draining soil to prevent root rot.
❄️ Winter: Cosmos are annuals and do not survive winter in cold climates. Remove dead plants after the first frost.
☀️ Summer: Water regularly during hot, dry periods. Deadhead spent flowers to encourage continued blooming. Provide support for taller varieties to prevent them from flopping over in strong winds.

Natal Plum Care Tips

Natal Plum is primarily an outdoor plant and requires significant sunlight to thrive. Growing it indoors is challenging due to its high light needs and potential size. It needs well-draining soil, moderate watering, and occasional fertilization. Toxicity to pets is a major concern.

  • Provide at least 6 hours of direct sunlight daily for optimal growth and fruit production.
  • Water deeply but infrequently, allowing the soil to dry slightly between waterings.
  • Fertilize regularly during the growing season with a balanced fertilizer.
  • Prune regularly to maintain shape and encourage new growth.
  • Protect from frost in colder climates.
❄️ Winter: Reduce watering frequency during winter. Protect from frost if grown in containers by moving indoors or providing insulation. Avoid fertilizing during dormancy.
☀️ Summer: Ensure adequate watering during hot summer months. Provide afternoon shade in extremely hot climates to prevent leaf scorch. Fertilize regularly to support growth and fruit production.

⚠️ Common Problems & Solutions — Plant Care Comparison

Cosmos

Common Issues: Powdery mildew, aphids, stem rot
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Aphids: Spray with insecticidal soap or neem oil. Stem rot: Avoid overwatering and ensure good drainage.

Natal Plum

Common Issues: Scale insects, mealybugs, root rot, lack of fruit production indoors.
Solutions: Scale/Mealybugs: Treat with insecticidal soap or neem oil. Root rot: Improve drainage and reduce watering frequency. Lack of fruit: Ensure adequate sunlight and pollination.

❓ Frequently Asked Questions — Comparing These Plants

Cosmos

What are the light requirements for Cosmos?

Cosmos require a minimum of six to eight hours of direct sunlight per day to thrive and produce abundant blooms. Insufficient sunlight can result in leggy growth, weak stems, and reduced flowering. Choose a sunny location in your garden or on your balcony where the plants will receive ample sunlight throughout the day. If growing Cosmos indoors, place them near a south-facing window that provides the brightest light. Rotate the plants regularly to ensure even exposure to sunlight on all sides. If natural light is insufficient, supplement with grow lights to provide the necessary light intensity.

How do I care for Cosmos?

Cosmos thrive in full sun and well-draining soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Fertilize lightly every few weeks with a balanced fertilizer, or a bloom-boosting formula during the flowering season, to encourage abundant blooms. Deadhead spent flowers regularly to promote continuous blooming. Cosmos are generally low-maintenance plants, but they may benefit from staking if they become tall and leggy. Prune them lightly to maintain their shape and encourage bushier growth. Protect them from strong winds, which can damage the delicate stems. Monitor for pests like aphids and treat them promptly if detected. Cosmos are generally annuals, but they may self-seed in some climates.

How do I propagate Cosmos?

Cosmos are most commonly propagated by seed. Sow seeds directly into the garden in spring after the last frost, or start them indoors 6-8 weeks earlier. For division, carefully dig up the plant in early spring or fall and separate the root ball into smaller clumps, ensuring each clump has healthy roots and foliage. Replant the divisions immediately in well-draining soil. Stem cuttings are not a common method for Cosmos, but can be attempted by taking 4-6 inch cuttings from new growth in spring, dipping them in rooting hormone, and planting them in moist potting mix. Keiki propagation is not applicable to Cosmos.

Natal Plum

What are the light requirements for Natal Plum?

Natal Plum requires ample sunlight to flourish and produce its characteristic blooms and fruits. Ideally, it should receive at least 6 hours of direct sunlight per day. In regions with intense sunlight, particularly during the hottest part of the day, providing some afternoon shade can prevent leaf scorch.

How do I care for Natal Plum?

Natal Plum thrives in full sun to partial shade. Ensure at least 6 hours of sunlight daily for optimal flowering and fruit production. Water thoroughly when the top inch of soil feels dry, allowing excess water to drain. Avoid overwatering, which can lead to root rot. Maintain moderate humidity, especially indoors.

How do I propagate Natal Plum?

Natal Plum can be propagated through stem cuttings. Take 4-6 inch stem cuttings from healthy, non-flowering shoots in spring or summer. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in a well-draining potting mix. Keep the soil moist and provide bright, indirect light. Rooting typically occurs within 4-8 weeks.

Last updated: May 6, 2026 — Plant care data reviewed and verified by our editorial team.