Achillea vs Delphinium Plant Comparison

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

Achillea

Achillea

Achillea millefolium

VS
Delphinium

Delphinium

Delphinium spp.

Achillea

Achillea

Achillea millefolium

Achillea millefolium, commonly known as Yarrow, is a herbaceous perennial prized for its fern-like foliage and clusters of small, daisy-like flowers. Typically grown outdoors in gardens, it forms a spreading mat of aromatic leaves. The flowers, which come in shades of white, yellow, pink, and red, bloom from late spring to late summer. Yarrow is valued for its medicinal properties, drought tolerance, and ability to attract pollinators. It's primarily an outdoor plant and struggles indoors due to high light requirements.

Asteraceae Native to Europe and Asia, naturalized in North America
✨ Features: Attracts pollinators, medicinal properties, drought tolerance
📖 Read Complete Achillea Guide
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

Quick Plant Comparison

Feature Achillea Delphinium
Light Full sun (at least 6 hours of direct sunlight daily) Full sun (at least 6 hours of direct sunlight per day)
Watering Every 1-2 weeks, depending on weather and soil drainage 2-3 times per week, depending on weather and soil drainage
Humidity 30-50% 40-60%
Temperature 15-25°C 15-24°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height 0.3-1 meter (outdoors) Not typically grown indoors; outdoors: 0.6-1.8 meters
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil, sandy or loamy soil is ideal. Avoid heavy clay soils. Well-draining, fertile soil rich in organic matter
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly (deadheading, weeding) 30 minutes weekly (weeding, watering, deadheading)

🔬 Botanical Information — Comparing These Plants

Achillea

Scientific Name Achillea millefolium
Family Asteraceae
Native To Native to Europe and Asia, naturalized in North America
Also Known As Yarrow, Common Yarrow, Milfoil
Leaves The leaves of yarrow are finely divided and fern-like, giving them a delicate, feathery appearance. They are typically green to grayish-green in color and are aromatic when crushed. The leaves are arranged alternately along the stems.
Flowers Yarrow rarely flowers indoors. Outdoors, it produces clusters of small, daisy-like flowers in shades of white, yellow, pink, or red. The flowers are long-lasting and attract a variety of pollinators.

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.

📏 Size & Growth — Plant Comparison

Achillea

Height 0.3-1 meter (outdoors)
Spread 0.3-1 meter (can spread via rhizomes)
Growth Rate Moderate
Growth Pattern Yarrow grows in a spreading, mat-forming habit. It sends up upright stems topped with flower clusters. It spreads via rhizomes, which can lead to it becoming somewhat aggressive in certain conditions.

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.

🌱 Propagation — Comparing Plant Growth

Achillea

Methods: Division, Seed, Stem cuttings

Difficulty: Easy

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

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.

✨ Benefits & Features — Comparing Plant Value

Achillea

Yarrow is known for its feathery foliage and clusters of small, daisy-like flowers. It also possesses medicinal properties and is highly attractive to pollinators. Its drought tolerance makes it a valuable addition to water-wise gardens.

  • ✓ Attracts beneficial insects and pollinators
  • ✓ Drought-tolerant and low-maintenance
  • ✓ Adds texture and color to the garden
  • ✓ Historically used for medicinal purposes
  • ✓ Can be used in cut flower arrangements
  • ⚠️ Toxic to pets

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

📅 Maintenance Schedule — Plant Care Comparison

Achillea

Repotting Not applicable for outdoor planting. If grown in containers, repot every 2-3 years or as needed.
Pruning Deadhead spent flowers regularly to encourage continued blooming. Cut back foliage in late fall or early spring.
Fertilizing Apply a balanced fertilizer (10-10-10) in early spring. Avoid over-fertilizing, as it can lead to leggy growth.
Seasonal Care In winter, cut back dead foliage. In spring, divide clumps if needed. In summer, deadhead spent flowers to encourage continued blooming.

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.

🌞 Light Requirements

Achillea

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

Low light tolerant: ❌ No

Delphinium

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

Low light tolerant: ❌ No

💧 Watering Needs

Achillea

Water deeply when the top inch of soil is dry. Avoid overwatering, as it can lead to root rot. Yarrow is drought-tolerant once established. Overwatering signs: yellowing leaves, wilting despite moist soil. Underwatering signs: dry, crispy leaves, stunted growth.

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.

🌡️ Temperature & Humidity

Achillea

Temperature: 15-25°C

Humidity: 30-50%

Delphinium

Temperature: 15-24°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Achillea

Achillea

Achillea millefolium
Care: Expert Time: 15 minutes weekly (deadheading, weeding) Beginner: No

Experienced gardeners looking for a drought-tolerant, pollinator-attracting plant for sunny gardens.

✅ Choose This Plant If...

  • You want a drought-tolerant plant for a sunny garden.
  • You want to attract pollinators to your garden.
  • You are interested in the medicinal properties of plants.
  • You want a low-maintenance perennial.
  • You enjoy the look of fern-like foliage and daisy-like flowers.

❌ Skip This Plant If...

  • You have pets that might ingest the plant, as it is toxic.
  • You don't have a location with full sun.
  • You are looking for an easy indoor plant.
📍 Ideal Location: Outdoor garden, sunny border, meadow garden
🎨 Style: Cottage, Wildflower, Naturalistic
🏠 Apartment Friendly: No
⚠️ Toxic to dogs, cats, and horses. Contains sesquiterpene lactones which can cause skin irritation, vomiting, diarrhea, and anorexia. All parts of the plant are considered toxic.
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.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

☀️

Achillea needs full sun (at least 6 hours of direct sunlight daily), while Delphinium prefers full sun (at least 6 hours of direct sunlight per day).

💡 Pro Tips For Comparing These Plants

Achillea Care Tips

Yarrow is primarily an outdoor plant and requires full sun to thrive. It's drought-tolerant and relatively low-maintenance once established. Growing it indoors is extremely challenging due to its high light requirements and tendency to spread. Indoor attempts often result in weak, leggy growth.

  • Plant in well-draining soil to prevent root rot.
  • Provide full sun for optimal growth and flowering.
  • Deadhead spent flowers regularly to encourage continued blooming.
  • Divide clumps every few years to prevent overcrowding.
  • Avoid over-fertilizing, as it can lead to leggy growth.
❄️ Winter: Cut back dead foliage in late fall or early winter. In colder climates, a layer of mulch can help protect the roots.
☀️ Summer: Deadhead spent flowers regularly to encourage continued blooming. Water deeply during dry spells. Provide adequate air circulation to prevent powdery mildew.

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.

⚠️ Common Problems & Solutions — Plant Care Comparison

Achillea

Common Issues: Powdery mildew, Root rot, Aphids
Solutions: Powdery mildew: Improve air circulation, apply fungicide. Root rot: Improve drainage, reduce watering. Aphids: Insecticidal soap, neem oil.

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.

❓ Frequently Asked Questions — Comparing These Plants

Achillea

What are the light requirements for Achillea?

Achillea thrives in full sun, requiring at least 6-8 hours of direct sunlight per day. Insufficient light can lead to leggy growth, reduced flowering, and weaker stems. When planting, choose a location that receives ample sunlight throughout the day. In hotter climates, some afternoon shade may be beneficial to prevent scorching of the foliage. For indoor cultivation (less common but possible), provide the brightest possible light, ideally with supplemental grow lights. Rotate the plant regularly to ensure even exposure to light.

How do I care for Achillea?

Achillea is relatively low-maintenance, thriving in well-drained soil and full sun. Water regularly after planting to help establish the root system. Once established, Achillea is drought-tolerant and prefers infrequent, deep watering. Fertilize in spring with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers to encourage continued blooming throughout the summer. Divide clumps every 2-3 years in spring or fall to prevent overcrowding and maintain vigor. Achillea benefits from good air circulation to prevent fungal diseases. Avoid overwatering, especially in heavy clay soils. Mulch around the base of the plant to retain moisture and suppress weeds.

How do I propagate Achillea?

Achillea can be easily propagated through division, stem cuttings, or seeds.

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.

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