Aster vs Japanese Cedar Plant Comparison

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

Aster

Aster

Aster spp.

VS
Japanese Cedar

Japanese Cedar

Cryptomeria japonica

Aster

Aster

Aster spp.

Asters are primarily late-summer and fall-blooming perennials, known for their daisy-like flowers in various shades of purple, pink, blue, and white. They are herbaceous plants, meaning they die back to the ground in winter and re-emerge in spring. Asters are popular garden plants, providing a burst of color when many other flowers are fading. They attract pollinators like bees and butterflies. While some species are more compact, others can be quite tall and spreading. Asters are generally outdoor plants and struggle indoors due to high light requirements and dormancy needs.

Asteraceae North America and Eurasia
✨ Features: Attracts pollinators, provides late-season color
📖 Read Complete Aster Guide
Japanese Cedar

Japanese Cedar

Cryptomeria japonica

Cryptomeria japonica, commonly known as Japanese Cedar or Sugi, is a large evergreen coniferous tree native to Japan and China. It's characterized by its reddish-brown bark that peels in strips and its spirally arranged, awl-shaped leaves that are typically bluish-green. In its native habitat, it can reach heights of 50-70 meters. While primarily an outdoor tree, some dwarf cultivars are grown in containers. People grow it for its ornamental value, fast growth (in suitable conditions), and use as a privacy screen or windbreak.

Cupressaceae Japan, China
✨ Features: Attractive foliage, aromatic wood, relatively fast growth (outdoors)
📖 Read Complete Japanese Cedar Guide

Quick Plant Comparison

Feature Aster Japanese Cedar
Light Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering. Full sun to partial shade
Watering Outdoors: Every 7-10 days, depending on weather and soil drainage. Indoors (not recommended): Much less frequent, allow soil to dry significantly between waterings. Every 1-2 weeks, depending on weather and soil drainage
Humidity 40-60% 30-60%
Temperature 15-25°C 10-24°C
Care Level Expert Expert
Growth Rate Moderate To Fast, Some Species Can Be Aggressive Spreaders Via Rhizomes Moderate To Fast
Max Height Outdoors: 30cm - 1.5m depending on species. Indoors: Unlikely to thrive, but if attempted, expect significantly smaller size. 2-5 meters (in containers, significantly smaller than in the wild)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-drained, loamy soil. A mix of garden soil, compost, and perlite is suitable. Well-draining, slightly acidic soil
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15-30 minutes weekly (weeding, watering, deadheading) 30 minutes weekly

🔬 Botanical Information — Comparing These Plants

Aster

Scientific Name Aster spp.
Family Asteraceae
Native To North America and Eurasia
Also Known As Aster, Michaelmas Daisy, Starwort
Leaves Aster leaves are typically lance-shaped to oval, with a slightly rough texture. The color is usually green, but can vary depending on the species. The size of the leaves ranges from small to medium.
Flowers Asters produce daisy-like flowers with a central disc and ray petals. The flower colors range from purple, pink, blue, and white. They bloom profusely in late summer and fall.

Japanese Cedar

Scientific Name Cryptomeria japonica
Family Cupressaceae
Native To Japan, China
Also Known As Japanese Cedar, Sugi
Leaves The leaves are awl-shaped, spirally arranged, and typically bluish-green. They are about 0.5-1 cm long and have a slightly prickly texture.
Flowers It rarely flowers indoors. Outdoors, it produces small, inconspicuous flowers in spring, followed by small, globular cones.

📏 Size & Growth — Plant Comparison

Aster

Height Outdoors: 30cm - 1.5m depending on species. Indoors: Unlikely to thrive, but if attempted, expect significantly smaller size.
Spread 30cm - 1m, depending on species. Some spread aggressively via rhizomes.
Growth Rate Moderate To Fast, Some Species Can Be Aggressive Spreaders Via Rhizomes
Growth Pattern Asters typically grow upright, forming bushy clumps. Some species spread via rhizomes, creating colonies of plants. The height and spread vary depending on the species and cultivar.

Japanese Cedar

Height 2-5 meters (in containers, significantly smaller than in the wild)
Spread 1-2 meters (in containers)
Growth Rate Moderate To Fast
Growth Pattern Outdoors, it grows into a large, pyramidal tree. Indoors, dwarf cultivars maintain a more compact, upright form.

🌱 Propagation — Comparing Plant Growth

Aster

Methods: Seed, stem cuttings, division

Difficulty: Easy To Moderate

Tips: Divide established clumps in spring or fall. Take stem cuttings in late spring or early summer. Sow seeds indoors 6-8 weeks before the last frost.

Japanese Cedar

Methods: Seed, Cuttings

Difficulty: Moderate

Tips: Take semi-hardwood cuttings in late summer. Use rooting hormone and provide high humidity. Seed propagation requires stratification.

✨ Benefits & Features — Comparing Plant Value

Aster

Asters are known for their late-season blooms, providing color when many other flowers have faded. They are also important food sources for pollinators preparing for winter. Some species are aggressive spreaders, forming large colonies over time.

  • ✓ Attracts pollinators to your garden.
  • ✓ Provides late-season color and extends the blooming season.
  • ✓ Relatively low-maintenance once established.
  • ✓ Can be used as cut flowers.
  • ✓ Adds a natural and wild aesthetic to the landscape.
  • ⚠️ Toxic to pets

Japanese Cedar

Japanese Cedar is a conifer that is not a true cedar, but belongs to the cypress family. Its reddish-brown bark and awl-shaped leaves give it a distinctive appearance. Dwarf cultivars are prized for their compact size and suitability for container growing.

  • ✓ Unique aesthetic appeal
  • ✓ Can be trained as bonsai
  • ✓ Provides a touch of nature indoors
  • ✓ Relatively slow-growing in containers
  • ✓ Offers a calming presence
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Aster

Repotting Not applicable for outdoor plants. If grown in containers (not recommended), repot every 1-2 years or as needed if root-bound, especially if a rhizomatous species.
Pruning Deadhead spent flowers to encourage more blooms. Cut back to the ground in late fall or early spring.
Fertilizing Balanced slow-release fertilizer in spring. A liquid fertilizer can be applied monthly during the growing season at half strength.
Seasonal Care Spring: Divide plants if needed, fertilize. Summer: Water regularly, deadhead spent flowers. Fall: Enjoy the blooms, cut back after flowering. Winter: Dormancy, minimal watering.

Japanese Cedar

Repotting Every 2-3 years, or as needed when the plant becomes root-bound
Pruning Prune to maintain shape and remove dead or damaged branches. Best done in late winter or early spring.
Fertilizing Balanced slow-release fertilizer in spring
Seasonal Care In winter, reduce watering and protect from frost if grown in a container. In summer, ensure adequate watering and provide some shade during the hottest part of the day.

🌞 Light Requirements

Aster

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

Low light tolerant: ❌ No

Japanese Cedar

Full sun to partial shade

Low light tolerant: ❌ No

💧 Watering Needs

Aster

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Asters prefer consistently moist but well-drained soil. Signs of underwatering include wilting leaves and dry, crispy edges. Overwatering symptoms include yellowing leaves and a soggy soil.

Japanese Cedar

Water deeply when the topsoil feels dry to the touch. Avoid overwatering, which can lead to root rot. In containers, ensure proper drainage. During the growing season, water more frequently, and reduce watering in the winter.

🌡️ Temperature & Humidity

Aster

Temperature: 15-25°C

Humidity: 40-60%

Japanese Cedar

Temperature: 10-24°C

Humidity: 30-60%

🤔 Which Plant Is Right For You?

Aster

Aster

Aster spp.
Care: Expert Time: 15-30 minutes weekly (weeding, watering, deadheading) Beginner: No

Gardeners looking for late-season color and pollinator-attracting plants.

✅ Choose This Plant If...

  • You want a burst of color in your garden in late summer and fall.
  • You want to attract pollinators like bees and butterflies to your yard.
  • You have a sunny garden space with well-drained soil.
  • You are looking for a relatively low-maintenance perennial for outdoor planting.
  • You enjoy cut flowers and want to add asters to your bouquets.

❌ Skip This Plant If...

  • You have limited sunlight indoors and cannot provide at least 6 hours of direct sun.
  • You have pets that might ingest the plant, as it is toxic to dogs, cats, and horses.
  • You are looking for a plant that thrives indoors with minimal effort.
📍 Ideal Location: Outdoor garden or flower bed with full sun exposure.
🎨 Style: Cottage, Traditional, Naturalistic
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Asters are toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, and skin irritation. The entire plant is considered toxic.
Japanese Cedar

Japanese Cedar

Cryptomeria japonica
Care: Expert Time: 30 minutes weekly Beginner: No

Experienced gardeners looking for a unique container plant for a bright, cool location.

✅ Choose This Plant If...

  • You appreciate the unique texture and form of conifers
  • You have a very bright, cool location for a container plant
  • You are an experienced gardener looking for a challenge
  • You want a small, slow-growing conifer for bonsai
  • You are prepared to provide specific care to maintain its health.

❌ Skip This Plant If...

  • You lack a very bright, cool location
  • You are a beginner gardener
  • You have pets that might ingest the plant
  • You want a low-maintenance houseplant.
📍 Ideal Location: Bright sunroom or cool greenhouse
🎨 Style: Japanese, Minimalist, Traditional
🏠 Apartment Friendly: Limited
⚠️ Although specific data is limited, conifers in general can be toxic to pets. The ASPCA lists some conifers as potentially causing gastrointestinal upset if ingested. Resin and sap can be irritating. All parts of the plant should be considered potentially harmful.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

📈

Aster has moderate to fast, some species can be aggressive spreaders via rhizomes growth, while Japanese Cedar grows moderate to fast.

💡 Pro Tips For Comparing These Plants

Aster Care Tips

Asters are primarily outdoor plants that require full sun and well-drained soil. They are not well-suited for indoor growing due to their high light requirements and dormancy needs. Indoor attempts will likely result in leggy growth and poor flowering. Regular deadheading encourages more blooms.

  • Provide full sun for optimal flowering.
  • Ensure well-drained soil to prevent root rot.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Divide plants every few years to prevent overcrowding.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: Cut back the plants to the ground after flowering. Apply a layer of mulch to protect the roots during winter. Minimal watering is needed during dormancy.
☀️ Summer: Water regularly during hot, dry weather. Deadhead spent flowers to encourage more blooms. Monitor for pests and diseases.

Japanese Cedar Care Tips

Japanese Cedar is primarily an outdoor tree and presents significant challenges when grown indoors. It requires very bright light, well-draining soil, and careful watering to prevent root rot. Maintaining adequate humidity indoors can also be difficult. Only dwarf cultivars are suitable for container growing, and even then, they may not thrive indoors long-term.

  • Provide excellent drainage to prevent root rot
  • Ensure adequate humidity, especially in dry indoor environments
  • Fertilize sparingly with a balanced fertilizer
  • Monitor for pests regularly
  • Rotate the plant regularly to ensure even growth.
❄️ Winter: Reduce watering in winter. Protect from frost if grown in a container. Provide bright light.
☀️ Summer: Ensure adequate watering during hot weather. Provide some shade during the hottest part of the day to prevent scorching.

⚠️ Common Problems & Solutions — Plant Care Comparison

Aster

Common Issues: Powdery mildew, aster yellows, aphids, spider mites
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Aster yellows: Remove and destroy infected plants. Aphids/Spider mites: Insecticidal soap or neem oil.

Japanese Cedar

Common Issues: Spider mites, Root rot, Browning foliage, Poor growth
Solutions: Spider mites: Treat with insecticidal soap or neem oil. Root rot: Improve drainage and reduce watering. Browning foliage: Ensure adequate watering and humidity. Poor growth: Provide sufficient light and fertilizer.

❓ Frequently Asked Questions — Comparing These Plants

Aster

What are the light requirements for Aster?

Asters are sun-loving plants and require at least 6-8 hours of direct sunlight per day to thrive and produce abundant blooms. Insufficient light can lead to leggy growth, reduced flowering, and weaker stems. When growing asters indoors, place them near a sunny window that receives ample sunlight. If natural light is limited, supplement with grow lights to ensure they receive adequate illumination. Rotate the plants regularly to ensure even light exposure on all sides. Avoid placing them in overly shaded areas, as this can hinder their growth and flowering potential. Southern or western exposure is ideal.

How do I care for Aster?

Asters thrive in well-draining soil and require regular watering, especially during dry periods. Aim to keep the soil consistently moist but not waterlogged. Fertilize regularly during the growing season with a balanced fertilizer to encourage abundant blooms. Deadhead spent flowers to promote continued flowering. Provide support for taller varieties to prevent them from flopping over. Asters prefer full sun, but some varieties can tolerate partial shade. Monitor for pests and diseases, and treat accordingly. Proper air circulation is important to prevent fungal issues. Prune back in late fall or early spring to maintain shape and vigor. Provide 6-8 hours of direct sunlight daily.

How do I propagate Aster?

Asters can be propagated by division, stem cuttings, or seeds.

Japanese Cedar

What are the light requirements for Japanese Cedar?

Japanese Cedars require bright, indirect light to thrive indoors. Direct sunlight can scorch their delicate foliage, leading to brown tips and overall stress. A location near an east-facing window is often ideal, providing ample morning light without the harsh afternoon sun. If placed near a south- or west-facing window, use sheer curtains to filter the light. Insufficient light can result in leggy growth and a loss of foliage density. Rotate the plant regularly to ensure all sides receive adequate light exposure. If natural light is limited, consider supplementing with a grow light to maintain healthy growth and vibrant color.

How do I care for Japanese Cedar?

Japanese Cedars thrive indoors with bright, indirect light; avoid direct sunlight, which can scorch the foliage. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain high humidity levels through misting or a humidifier, especially during dry months. Use a well-draining potting mix formulated for conifers or evergreens. Fertilize sparingly during the growing season (spring and summer) with a balanced, slow-release fertilizer. Prune regularly to maintain the desired shape and size. Repot every 2-3 years as needed, choosing a slightly larger pot. Provide stable temperatures, avoiding sudden fluctuations and drafts. Rotate the plant regularly to ensure even growth. Monitor for pests like spider mites and treat promptly.

How do I propagate Japanese Cedar?

Japanese Cedars can be propagated through stem cuttings or air layering, though success rates can vary. For stem cuttings, take 4-6 inch cuttings from new growth in spring or early summer. Remove the lower needles and dip the cut end in rooting hormone. Plant the cutting in a well-draining potting mix and keep it moist and humid by covering with a plastic bag or humidity dome. For air layering, make a small incision on a branch, wrap it with moist sphagnum moss, and cover it with plastic wrap. Secure the wrap tightly and keep the moss moist. Once roots have formed, cut the branch below the rooted section and pot it up. Both methods require patience and consistent care.

Last updated: May 5, 2026 — Plant care data reviewed and verified by our editorial team.