Delphinium vs Perennial Pea Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
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.
Perennial Pea
Lathyrus latifolius
Lathyrus latifolius, commonly known as Perennial Pea, is a climbing perennial vine that can reach lengths of 6 feet or more. It features winged stems and tendrils that allow it to scramble over other plants or structures. The plant produces showy, pea-like flowers in shades of pink, rose, purple, and white during the summer months. While visually appealing, it's primarily an outdoor plant and not suited for indoor cultivation due to its need for full sun and extensive root system. People grow it for its attractive flowers and ability to cover fences or trellises.
Quick Plant Comparison
| Feature | Delphinium | Perennial Pea |
|---|---|---|
| Light | Full sun (at least 6 hours of direct sunlight per day) | Full sun (at least 6 hours of direct sunlight daily) |
| Watering | 2-3 times per week, depending on weather and soil drainage | Every 7-10 days, depending on weather conditions |
| Humidity | 40-60% | 30-50% |
| Temperature | 15-24°C | 15-25°C |
| Care Level | Expert | Expert |
| Growth Rate | Moderate | Fast |
| Max Height | Not typically grown indoors; outdoors: 0.6-1.8 meters | N/A (Outdoor plant, not suitable for indoor growing) |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining, fertile soil rich in organic matter | Well-drained soil, loamy or sandy soil is preferred |
| Beginner Friendly | ❌ No | ❌ No |
| Weekly Maintenance | 30 minutes weekly (weeding, watering, deadheading) | 30 minutes weekly during growing season |
🔬 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. |
Perennial Pea
| Scientific Name | Lathyrus latifolius |
|---|---|
| Family | Fabaceae |
| Native To | Europe |
| Also Known As | Perennial Pea, Everlasting Pea, Broad-leaved Everlasting Pea |
| Leaves | The leaves are alternate, pinnately compound with two leaflets and a terminal tendril. The leaflets are lance-shaped, 5-10 cm long, and have a bluish-green color. |
| Flowers | The flowers are pea-like, about 2-3 cm wide, and come in shades of pink, rose, purple, and white. They are borne in clusters on long stalks during the summer months. It will not flower indoors. |
📏 Size & Growth — Plant Comparison
Delphinium
Perennial Pea
🌱 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.
Perennial Pea
Methods: Seed, Division, Root cuttings
Difficulty: Easy
Tips: Soak seeds in warm water for 24 hours before planting to improve germination. Divide established plants in spring or fall. Root cuttings can be taken in late fall or early spring.
✨ 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
Perennial Pea
The Perennial Pea is a long-lived perennial vine with showy flowers. Unlike some other pea species, it does not produce edible pods.
- ✓ Attracts pollinators like bees and butterflies.
- ✓ Provides beautiful vertical interest in the garden.
- ✓ Relatively low maintenance once established.
- ✓ Can help to stabilize soil on slopes.
- ✓ Offers a long blooming period throughout the summer.
- ⚠️ Toxic to pets
📅 Maintenance Schedule — Plant Care Comparison
Delphinium
Perennial Pea
🌞 Light Requirements
Delphinium
Full sun (at least 6 hours of direct sunlight per day)
Low light tolerant: ❌ No
Perennial Pea
Full sun (at least 6 hours of direct sunlight daily)
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.
Perennial Pea
Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. During hot, dry periods, more frequent watering may be necessary. Allow the soil to drain well after watering.
🌡️ Temperature & Humidity
Delphinium
Temperature: 15-24°C
Humidity: 40-60%
Perennial Pea
Temperature: 15-25°C
Humidity: 30-50%
🤔 Which Plant Is Right For You?
Delphinium
Delphinium spp.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.
Perennial Pea
Lathyrus latifoliusGardeners looking for a flowering vine to cover fences, trellises, or walls in a sunny location.
✅ Choose This Plant If...
- You want a fast-growing vine to cover a fence or trellis.
- You have a sunny garden and want to attract pollinators.
- You enjoy the look of pea-like flowers in various colors.
- You are looking for a low-maintenance perennial once established.
- You want a plant that can tolerate a wide range of soil conditions.
❌ Skip This Plant If...
- You have pets or small children who might ingest the plant.
- You have a small garden and are concerned about aggressive spreading.
- You are looking for an indoor plant.
- You don't have a location with full sun.
- You are sensitive to plants that may cause skin irritation.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Delphinium needs full sun (at least 6 hours of direct sunlight per day), while Perennial Pea prefers full sun (at least 6 hours of direct sunlight daily).
Delphinium has moderate growth, while Perennial Pea grows fast.
💡 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.
Perennial Pea Care Tips
Perennial Pea is an outdoor plant that requires full sun and well-drained soil. It is not suitable for indoor growing due to its light and space requirements. It can be an aggressive spreader, so containment may be necessary. Toxicity to pets is a significant concern.
- Provide a sturdy support structure for the vine to climb.
- Deadhead spent flowers to encourage continued blooming.
- Monitor for signs of powdery mildew and treat promptly.
- Control spread by pruning and removing unwanted seedlings.
- Avoid planting near areas where pets or children have access.
⚠️ Common Problems & Solutions — Plant Care Comparison
Delphinium
Perennial Pea
❓ 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.
Perennial Pea
What are the light requirements for Perennial Pea?
Perennial Pea requires at least 6-8 hours of direct sunlight per day to thrive and produce abundant blooms. A south-facing location is ideal, but east or west-facing exposures can also work if they provide sufficient sunlight. In hotter climates, some afternoon shade can be beneficial to prevent scorching of the leaves and flowers. Insufficient light can lead to leggy growth, reduced flowering, and pale foliage. If growing indoors, supplement with grow lights if natural light is limited. Rotate the plant regularly to ensure even light exposure on all sides. Monitor your Perennial Pea closely and adjust its location as needed to ensure it receives adequate sunlight.
How do I care for Perennial Pea?
Perennial Pea thrives in full sun to partial shade and requires well-drained soil. Water regularly, especially during dry periods, but avoid overwatering, which can lead to root rot. Fertilize in spring with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers to encourage continued flowering throughout the season. Provide a sturdy support structure, such as a trellis or fence, for the plant to climb. Prune back in late fall or early spring to control its size and shape. Watch out for common pests like aphids and spider mites, and treat infestations promptly. Mulch around the base of the plant to retain moisture and suppress weeds. Regular monitoring and preventative measures are key to keeping your Perennial Pea healthy and vibrant.
How do I propagate Perennial Pea?
Perennial Pea can be propagated by seed, division, or stem cuttings. For seed propagation, scarify the seeds and soak them in water for 24 hours before planting. Sow seeds indoors in early spring or directly outdoors after the last frost. For division, carefully dig up a mature plant in early spring or late fall and divide the root ball into smaller sections, each with its own set of roots and shoots. Replant the divisions in well-draining soil. For stem cuttings, take 4-6 inch cuttings from healthy stems in late spring or early summer. 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 until they root.
Last updated: May 2, 2026 — Plant care data reviewed and verified by our editorial team.