Delphinium vs Rain Lily Plant Comparison

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

Delphinium

Delphinium

Delphinium spp.

VS
Rain Lily

Rain Lily

Zephyranthes spp.

Delphinium

Delphinium

Delphinium spp.

Delphiniums are perennial herbaceous plants known for their tall, striking flower spikes. They typically grow outdoors and are prized for their vibrant blue, purple, pink, and white flowers. The plant has deeply lobed leaves and a robust stem that supports the flower spike. They are not suited for indoor growing due to their high light requirements and size. People grow them in gardens for their aesthetic appeal and to attract pollinators.

Ranunculaceae Northern Hemisphere, including Europe, Asia, and North America
✨ Features: Attracts pollinators (bees and butterflies)
📖 Read Complete Delphinium Guide
Rain Lily

Rain Lily

Zephyranthes spp.

Rain Lilies are small, bulbous perennials known for their delightful, trumpet-shaped flowers that often appear after rainfall, hence the name. They typically grow to a height of 15-30 cm. The foliage consists of slender, grass-like leaves. While they can be grown indoors, they thrive outdoors in well-draining soil and plenty of sunlight. People grow them for their charming blooms, ease of care (outdoors), and ability to naturalize in suitable climates. They are popular in rock gardens, borders, and containers.

Amaryllidaceae Americas, from the United States to Argentina
✨ Features: Flowers appear after rainfall, attracting pollinators.
📖 Read Complete Rain Lily Guide

Quick Plant Comparison

Feature Delphinium Rain Lily
Light Full sun (at least 6 hours of direct sunlight per day) Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering.
Watering 2-3 times per week, depending on weather and soil drainage Every 7-10 days during the growing season, less frequently during dormancy.
Humidity 40-60% 40-60%
Temperature 15-24°C 18-27°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height Not typically grown indoors; outdoors: 0.6-1.8 meters 15-30 cm
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, fertile soil rich in organic matter Well-draining soil mix, such as a sandy loam or a mix of potting soil, perlite, and sand.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes weekly (weeding, watering, deadheading) 5 minutes weekly (outdoors)

🔬 Botanical Information — Comparing These Plants

Delphinium

Scientific Name Delphinium spp.
Family Ranunculaceae
Native To Northern Hemisphere, including Europe, Asia, and North America
Also Known As Larkspur, Delphinium
Leaves The leaves are deeply lobed and palmate, with a coarse texture. They are typically medium to dark green in color and arranged alternately along the stem.
Flowers Delphiniums rarely, if ever, flower indoors. Outdoors, they produce tall, dense spikes of flowers in shades of blue, purple, pink, and white. The flowers have a distinctive spurred shape.

Rain Lily

Scientific Name Zephyranthes spp.
Family Amaryllidaceae
Native To Americas, from the United States to Argentina
Also Known As Rain Lily, Fairy Lily, Zephyr Lily
Leaves The leaves are slender, linear, and grass-like, typically 15-30 cm long and 0.5-1 cm wide. They are usually a medium green color and have a smooth texture.
Flowers Rain Lilies can flower indoors, but it is less common and less prolific than outdoors. The flowers are trumpet-shaped, with six petals, and come in various colors, including white, pink, yellow, and red. They typically last for a few days.

📏 Size & Growth — Plant Comparison

Delphinium

Height Not typically grown indoors; outdoors: 0.6-1.8 meters
Spread Outdoors: 0.3-0.6 meters
Growth Rate Moderate
Growth Pattern Upright, with tall, sturdy stems that support the flower spikes. The plant forms a basal rosette of leaves from which the flowering stems emerge.

Rain Lily

Height 15-30 cm
Spread 5-10 cm
Growth Rate Moderate
Growth Pattern Rain Lilies grow from bulbs and produce upright, grass-like foliage. The flowers emerge on slender stalks, held above the foliage. They tend to form clumps over time as the bulbs multiply.

🌱 Propagation — Comparing Plant Growth

Delphinium

Methods: Seed, Division, Stem cuttings

Difficulty: Moderate

Tips: Sow seeds in early spring or fall. Divide established plants in spring or fall. Take stem cuttings in late spring.

Rain Lily

Methods: Division, Seed

Difficulty: Easy

Tips: Divide bulbs after flowering or collect and sow seeds in spring. For division, gently separate offsets from the main bulb and replant them in well-draining soil. For seeds, sow them in a seed-starting mix and keep them moist until germination.

✨ Benefits & Features — Comparing Plant Value

Delphinium

Delphiniums are known for their towering flower spikes, which can reach impressive heights. The intense blue color of some varieties is particularly striking and relatively rare in the plant world.

  • ✓ Attracts pollinators to the garden
  • ✓ Adds vibrant color and height to flower beds
  • ✓ Provides cut flowers for arrangements
  • ✓ Enhances the aesthetic appeal of outdoor spaces
  • ✓ Can be used in traditional medicine (with caution and expert knowledge)
  • ⚠️ Toxic to pets

Rain Lily

The most unique characteristic is their tendency to bloom after rainfall, a phenomenon that is triggered by the sudden increase in moisture. This makes them a delightful surprise in the garden. The flowers are also relatively short-lived, adding to their ephemeral charm.

  • ✓ Attracts pollinators to the garden.
  • ✓ Adds a splash of color to the landscape.
  • ✓ Low maintenance once established.
  • ✓ Can be grown in containers or in the ground.
  • ✓ Provides a natural, informal aesthetic.
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Delphinium

Repotting Not applicable for indoor growing; for outdoor plants, division may be needed every 3-4 years.
Pruning Deadhead spent flowers to encourage further blooming. Cut back foliage in the fall.
Fertilizing Balanced fertilizer (10-10-10) applied in spring and early summer at half strength
Seasonal Care Spring: Fertilize and provide support for tall flower spikes. Summer: Water regularly and deadhead spent flowers. Fall: Cut back foliage after flowering. Winter: Provide mulch for protection in colder climates.

Rain Lily

Repotting Repot every 2-3 years or when the bulbs become overcrowded. Use fresh, well-draining soil.
Pruning Remove spent flowers and yellowing leaves to maintain appearance and prevent disease.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, applied every 4-6 weeks during the growing season.
Seasonal Care In winter, reduce watering and protect from frost. In summer, provide regular watering and fertilization during the growing season. Allow for a dry dormant period after flowering to encourage future blooms.

🌞 Light Requirements

Delphinium

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

Low light tolerant: ❌ No

Rain Lily

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

Low light tolerant: ❌ No

💧 Watering Needs

Delphinium

Water deeply when the top inch of soil feels dry. Avoid overhead watering to prevent fungal diseases. Overwatering can lead to root rot, indicated by yellowing leaves and a mushy stem. Underwatering results in wilting and dry, crispy leaves.

Rain Lily

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to bulb rot. Reduce watering during dormancy. Signs of overwatering include yellowing leaves and a mushy bulb. Underwatering results in dry, brittle leaves and stunted growth.

🌡️ Temperature & Humidity

Delphinium

Temperature: 15-24°C

Humidity: 40-60%

Rain Lily

Temperature: 18-27°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Delphinium

Delphinium

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

Gardeners looking to add height and vibrant color to their flower beds.

✅ Choose This Plant If...

  • You want a tall, dramatic flower for your garden.
  • You want to attract pollinators to your yard.
  • You have a sunny garden spot with well-draining soil.
  • You enjoy the classic cottage garden aesthetic.
  • You are an experienced gardener looking for a rewarding challenge.

❌ Skip This Plant If...

  • You have limited sunlight in your home.
  • You have pets or small children who might ingest the plant.
  • You are a beginner gardener looking for an easy-to-grow plant.
📍 Ideal Location: Outdoor garden bed with full sun exposure
🎨 Style: Cottage, Traditional, English Garden
🏠 Apartment Friendly: No
⚠️ Toxic to dogs, cats, and horses. All parts of the plant, especially the seeds, contain toxic alkaloids. Symptoms include gastrointestinal upset, weakness, and potentially cardiac problems.
Rain Lily

Rain Lily

Zephyranthes spp.
Care: Expert Time: 5 minutes weekly (outdoors) Beginner: No

Gardeners in warm climates looking for low-maintenance, flowering plants for borders, rock gardens, or containers.

✅ Choose This Plant If...

  • You live in a warm climate with mild winters.
  • You want a low-maintenance plant for your garden.
  • You enjoy flowers that bloom after rainfall.
  • You have a sunny garden or rock garden.
  • You want to attract pollinators to your garden.

❌ Skip This Plant If...

  • You live in a cold climate with harsh winters.
  • You have pets that might ingest the plant.
  • You don't have a sunny location.
  • You want a plant that flowers reliably indoors.
📍 Ideal Location: Outdoors in a sunny garden bed or container.
🎨 Style: Cottage, Naturalistic, Mediterranean
🏠 Apartment Friendly: Limited
⚠️ All parts of the plant, especially the bulb, contain lycorine and other alkaloids that are toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, abdominal pain, tremors, and cardiac arrhythmias. (Source: ASPCA)

🎯 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

Delphinium Care Tips

Delphiniums are primarily outdoor plants and are very challenging to grow indoors due to their high light requirements and need for specific temperature and humidity conditions. They require full sun, well-draining soil, and regular fertilization. Indoor cultivation is not recommended.

  • Provide support for tall flower spikes to prevent them from bending or breaking.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Protect from slugs and snails, especially young plants.
  • Ensure good drainage to prevent root rot.
  • Apply a layer of mulch around the base of the plant to retain moisture and suppress weeds.
❄️ Winter: Cut back foliage after flowering. Apply a layer of mulch around the base of the plant to protect the crown from freezing temperatures. In colder climates, consider providing additional winter protection.
☀️ Summer: Water regularly during hot, dry periods. Deadhead spent flowers to encourage more blooms. Provide support for tall flower spikes to prevent them from bending or breaking in strong winds.

Rain Lily Care Tips

Rain Lilies are best suited for outdoor cultivation. Indoor growing is challenging due to high light requirements. They need well-draining soil, regular watering during the growing season, and protection from frost. Indoor plants rarely flower as prolifically as outdoor ones.

  • Plant bulbs in well-draining soil to prevent rot.
  • Provide full sun for optimal flowering.
  • Water deeply but infrequently, allowing the soil to dry out between waterings.
  • Fertilize during the growing season to encourage blooms.
  • Protect from frost in colder climates.
❄️ Winter: In colder climates, Rain Lily bulbs should be dug up and stored in a cool, dry place over the winter. In milder climates, reduce watering and protect from frost.
☀️ Summer: Provide regular watering and fertilization during the growing season. Ensure adequate sunlight for optimal flowering.

⚠️ Common Problems & Solutions — Plant Care Comparison

Delphinium

Common Issues: Powdery mildew, Crown rot, Aphids, Slugs/Snails
Solutions: Powdery mildew: Improve air circulation and apply fungicide. Crown rot: Ensure good drainage and avoid overwatering. Aphids: Spray with insecticidal soap. Slugs/Snails: Use slug bait or handpick.

Rain Lily

Common Issues: Bulb rot, spider mites, lack of flowering indoors
Solutions: Ensure well-draining soil and avoid overwatering to prevent bulb rot. Treat spider mites with insecticidal soap or neem oil. Provide ample sunlight and a period of dormancy to encourage flowering.

❓ Frequently Asked Questions — Comparing These Plants

Delphinium

What are the light requirements for Delphinium?

Delphiniums are sun-loving plants and require at least six hours of direct sunlight daily to flourish. Insufficient light can lead to weak stems, poor flowering, and increased susceptibility to diseases. In hotter climates, some afternoon shade can be beneficial to prevent scorching. When selecting a location, consider the sun’s path and ensure the plants receive ample morning sun. Delphiniums grown in partial shade may still survive, but their blooms will be significantly diminished. If growing indoors, supplement with grow lights to provide the necessary intensity and duration of light. Rotate the plant regularly to ensure even light exposure.

How do I care for Delphinium?

Delphiniums require specific care to thrive. Plant in well-draining soil enriched with organic matter. Full sun (at least 6 hours daily) is crucial for optimal blooming. Water deeply but infrequently, allowing the soil to dry slightly between waterings. Fertilize regularly during the growing season with a balanced fertilizer, switching to a high-phosphorus fertilizer as buds develop to promote abundant blooms. Stake tall varieties to prevent them from collapsing under the weight of their flowers or in windy conditions. Deadhead spent blooms to encourage reblooming. Protect from slugs and snails, which can damage young plants. Provide adequate air circulation to prevent fungal diseases. Mulch around the base of the plant to retain moisture and suppress weeds.

How do I propagate Delphinium?

Delphiniums can be propagated through division, stem cuttings, and seeds. Division involves separating mature clumps in early spring or fall. Carefully dig up the plant and divide the root ball into sections, ensuring each section has healthy roots and shoots. Stem cuttings can be taken in spring. Select healthy, non-flowering stems and cut them into 4-6 inch sections. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in a well-draining potting mix and keep them moist. Seeds can be sown indoors in late winter or early spring. Sow seeds thinly in a seed starting mix and keep them moist and warm. Germination typically takes 2-3 weeks.

Rain Lily

What are the light requirements for Rain Lily?

Rain Lilies thrive in bright, indirect light. Indoors, place them near an east- or west-facing window where they can receive several hours of sunlight daily. If you notice the leaves becoming pale or leggy, it indicates insufficient light. Conversely, scorching can occur if they are exposed to intense, direct sunlight, especially during the hottest part of the day. Rotate the pot regularly to ensure even light exposure on all sides of the plant. Supplement with grow lights if natural light is limited, especially during winter months.

How do I care for Rain Lily?

Rain Lilies are relatively easy to care for, requiring well-draining soil and bright, indirect light. Water thoroughly when the top inch of soil feels dry, and allow the soil to dry out slightly between waterings. Fertilize with a balanced liquid fertilizer during the growing season (spring and summer) to encourage blooming. Repot every 2-3 years or when the bulbs become overcrowded. Protect from frost in colder climates by bringing potted plants indoors or mulching garden beds. Deadhead spent flowers to promote further blooming. Provide adequate drainage to prevent root rot, and ensure good air circulation. Avoid overwatering, especially during dormancy.

How do I propagate Rain Lily?

Rain Lilies can be easily propagated by division. When repotting, gently separate the bulbs and plant them in individual pots. Offsets, or small bulbs that form around the base of the main bulb, can also be removed and planted. Stem cuttings are not applicable for Rain Lilies as they grow from bulbs. Keikis are not applicable for Rain Lilies. Ensure each division has healthy roots. Plant in well-draining soil and water thoroughly. Keep the soil consistently moist until new growth appears.

Last updated: May 10, 2026 — Plant care data reviewed and verified by our editorial team.