Aster vs Sweet Pea 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
Sweet Pea

Sweet Pea

Lathyrus odoratus

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
Sweet Pea

Sweet Pea

Lathyrus odoratus

Sweet peas are annual climbing plants, known for their beautiful, fragrant flowers. They are not naturally indoor plants and are typically grown outdoors in gardens. They feature delicate, papery petals in a wide range of colors, including pink, purple, red, white, and bi-colors. Sweet peas climb using tendrils, reaching heights of 1 to 2 meters. People grow them for their ornamental value, the delightful fragrance of their blooms, and their use as cut flowers.

Fabaceae Sicily, Cyprus, Southern Italy, and the Aegean Islands
✨ Features: Highly fragrant flowers, attractive to pollinators.
📖 Read Complete Sweet Pea Guide

Quick Plant Comparison

Feature Aster Sweet Pea
Light Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering. Full sun (at least 6-8 hours of direct sunlight per day)
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 2-3 days outdoors, depending on weather conditions. Less frequent if grown indoors.
Humidity 40-60% 40-60%
Temperature 15-25°C 13-18°C
Care Level Expert Expert
Growth Rate Moderate To Fast, Some Species Can Be Aggressive Spreaders Via Rhizomes Fast
Max Height Outdoors: 30cm - 1.5m depending on species. Indoors: Unlikely to thrive, but if attempted, expect significantly smaller size. 1-2 meters (outdoors). Significantly smaller if grown indoors.
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, fertile soil rich in organic matter. A mix of garden soil, compost, and perlite is suitable.
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.

Sweet Pea

Scientific Name Lathyrus odoratus
Family Fabaceae
Native To Sicily, Cyprus, Southern Italy, and the Aegean Islands
Also Known As Sweet Pea
Leaves The leaves are ovate to lanceolate, with a bluish-green color. They are arranged alternately along the stem and have prominent veins. The plant also produces tendrils that aid in climbing.
Flowers Sweet peas produce fragrant, papery flowers in a wide range of colors, including pink, purple, red, white, and bi-colors. They bloom profusely outdoors during the summer months. Flowering is rare and limited indoors.

📏 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.

Sweet Pea

Height 1-2 meters (outdoors). Significantly smaller if grown indoors.
Spread 30-60 cm
Growth Rate Fast
Growth Pattern Sweet peas are climbing annuals that use tendrils to attach to supports. They grow vertically, reaching heights of 1 to 2 meters outdoors. Indoors, growth is typically more constrained.

🌱 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.

Sweet Pea

Methods: Seed

Difficulty: Easy

Tips: Soak seeds in water for 24 hours before sowing to improve germination. Sow directly into the ground or in pots in early spring.

✨ 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

Sweet Pea

Sweet peas are known for their intense fragrance and wide range of colors. Their climbing habit and delicate petals make them a popular choice for cottage gardens and cut flower arrangements.

  • ✓ Beautiful and fragrant flowers
  • ✓ Attracts pollinators to the garden
  • ✓ Provides cut flowers for bouquets
  • ✓ Adds a touch of romance to the garden
  • ✓ Can be grown in a variety of colors
  • ⚠️ 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.

Sweet Pea

Repotting Not applicable as it's an annual. If grown indoors, repotting may be needed if the container is too small.
Pruning Pinch off the tips of young plants to encourage bushier growth. Deadhead spent flowers to promote continued blooming.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 2-3 weeks during the growing season.
Seasonal Care In spring, sow seeds and provide support for climbing. In summer, water regularly and fertilize. In fall, collect seeds for next year. In winter, the plant dies back as it is an annual.

🌞 Light Requirements

Aster

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

Low light tolerant: ❌ No

Sweet Pea

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

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.

Sweet Pea

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Ensure good drainage. Underwatering will cause wilting and reduced flowering.

🌡️ Temperature & Humidity

Aster

Temperature: 15-25°C

Humidity: 40-60%

Sweet Pea

Temperature: 13-18°C

Humidity: 40-60%

🤔 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.
Sweet Pea

Sweet Pea

Lathyrus odoratus
Care: Expert Time: 30 minutes weekly Beginner: No

Experienced gardeners who want to grow fragrant flowers outdoors.

✅ Choose This Plant If...

  • You love fragrant flowers and have a sunny outdoor garden.
  • You enjoy growing cut flowers for bouquets.
  • You want to attract pollinators to your garden.
  • You are an experienced gardener looking for a rewarding challenge.
  • You appreciate the wide variety of colors and forms available in sweet pea cultivars.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You lack a sunny outdoor space.
  • You are a beginner gardener looking for an easy-to-grow plant.
📍 Ideal Location: Sunny garden or balcony with support for climbing.
🎨 Style: Cottage, Romantic, Traditional
🏠 Apartment Friendly: Limited
⚠️ All parts of the sweet pea plant, especially the seeds, are toxic to dogs, cats, and horses. Symptoms include weakness, tremors, and seizures. Consult a veterinarian immediately if ingestion is suspected.

🎯 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 Sweet Pea grows 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.

Sweet Pea Care Tips

Sweet peas are challenging to grow indoors due to their high light requirements and need for cool temperatures. They require consistent watering, fertilization, and support for climbing. Without ideal conditions, flowering will be limited.

  • Soak seeds overnight before planting to improve germination.
  • Provide a sturdy trellis or support for climbing.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Fertilize every 2-3 weeks during the growing season.
  • Protect from strong winds.
❄️ Winter: As an annual, the plant will die back in winter. Collect seeds for planting the following spring.
☀️ Summer: Provide regular watering and fertilization during the growing season. Protect from intense afternoon sun in hot climates. Deadhead spent flowers to encourage continued blooming.

⚠️ 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.

Sweet Pea

Common Issues: Powdery mildew, aphids, lack of flowering, root rot
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Aphids: Spray with insecticidal soap. Lack of flowering: Ensure adequate sunlight and fertilization. Root rot: Improve drainage and reduce watering frequency.

❓ 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.

Sweet Pea

What are the light requirements for Sweet Pea?

Sweet Peas require at least 6-8 hours of direct sunlight per day to thrive and produce abundant blooms. A south-facing location is ideal, especially in cooler climates. If growing indoors, place your Sweet Peas near a sunny window or use grow lights to supplement natural light. Insufficient light can lead to leggy growth, fewer flowers, and pale foliage. Rotate the plants regularly to ensure even light exposure. In hot climates, provide some afternoon shade to prevent scorching. Monitor the leaves for signs of sunburn, such as brown spots, and adjust the plant’s position accordingly. Good air circulation is also important to prevent fungal diseases that can be exacerbated by inadequate light.

How do I care for Sweet Pea?

Sweet Peas thrive in full sun and well-drained soil. Sow seeds directly into the ground in early spring or late fall, depending on your climate. Soaking the seeds overnight can improve germination. Provide a sturdy support system, such as a trellis or netting, for the vines to climb. Water regularly, especially during dry periods, and fertilize every 2-3 weeks with a balanced fertilizer to encourage abundant blooming. Deadhead spent flowers to promote continued flowering. Protect plants from pests like aphids and slugs. Ensure good air circulation to prevent fungal diseases. Sweet Peas prefer cooler temperatures, so provide shade during the hottest part of the day in warmer climates. Monitor for signs of powdery mildew and treat promptly. Proper staking and pruning are crucial for healthy growth and prolific blooms.

How do I propagate Sweet Pea?

Sweet Peas are primarily propagated by seed.

Last updated: May 12, 2026 — Plant care data reviewed and verified by our editorial team.