Kale (Ornamental) vs Soapwort Plant Comparison

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

Kale (Ornamental)

Kale (Ornamental)

Brassica oleracea var. sabellica

VS
Soapwort

Soapwort

Saponaria officinalis

Kale (Ornamental)

Kale (Ornamental)

Brassica oleracea var. sabellica

Ornamental kale is a cool-season biennial grown as an annual for its vibrant, colorful foliage. It is not grown for consumption, though it is related to edible kale. The plant forms a rosette of frilly or ruffled leaves in shades of white, pink, purple, and red. Ornamental kale is primarily an outdoor plant, thriving in cooler temperatures and full sun. It is often used in fall and winter gardens for its striking visual appeal, providing color when many other plants are dormant. While technically possible to grow indoors, it is challenging to provide the necessary light and temperature conditions for optimal growth.

Brassicaceae Europe and Asia
✨ Features: Provides vibrant color in cool-season gardens.
📖 Read Complete Kale (Ornamental) Guide
Soapwort

Soapwort

Saponaria officinalis

Saponaria officinalis, commonly known as soapwort, is a herbaceous perennial plant that grows to about 30-90 cm tall. It features lance-shaped, opposite leaves and clusters of fragrant, five-petaled flowers that are typically pink or white. Soapwort is primarily an outdoor plant, known for its historical use as a soap substitute due to the saponins found in its roots and leaves, which create a lather when agitated in water. People grow it in gardens for its attractive flowers and historical interest, though it can be invasive.

Caryophyllaceae Eurasia
✨ Features: Historical use as a soap substitute; attractive, fragrant flowers.
📖 Read Complete Soapwort Guide

Quick Plant Comparison

Feature Kale (Ornamental) Soapwort
Light Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for best color development. Full sun to partial shade
Watering Every 3-7 days depending on environmental conditions and pot size. Every 7-10 days, depending on weather and soil drainage
Humidity 40-60% 30-50%
Temperature 10-18°C 15-25°C
Care Level Expert Expert
Growth Rate Moderate Fast
Max Height Indoors: 15-30 cm (6-12 inches) 30-90 cm (outdoors); significantly smaller if grown in a container indoors, likely 30-45cm
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining potting mix rich in organic matter. Well-draining soil, such as a sandy loam
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 5-10 minutes weekly 15 minutes weekly (weeding, deadheading)

🔬 Botanical Information — Comparing These Plants

Kale (Ornamental)

Scientific Name Brassica oleracea var. sabellica
Family Brassicaceae
Native To Europe and Asia
Also Known As Ornamental Kale, Flowering Kale, Decorative Kale
Leaves The leaves of ornamental kale are broad and frilly or ruffled, with varying degrees of texture. They come in a range of colors, including white, pink, purple, and red, often with contrasting veins and edges. The leaves can be quite large, reaching up to 30 cm (12 inches) in diameter.
Flowers Ornamental kale will bolt and produce flowers in its second year, typically after a period of cold exposure. The flowers are small and yellow, similar to other members of the Brassica family. However, it is typically grown as an annual, so flowering is not common.

Soapwort

Scientific Name Saponaria officinalis
Family Caryophyllaceae
Native To Eurasia
Also Known As Common Soapwort, Bouncing Bet, Fuller's Herb, Sweet William
Leaves The leaves are lance-shaped, opposite, and typically 5-7 cm long. They are smooth and have a slightly grayish-green color.
Flowers Soapwort produces clusters of fragrant, five-petaled flowers that are typically pink or white. It rarely flowers indoors due to insufficient light.

📏 Size & Growth — Plant Comparison

Kale (Ornamental)

Height Indoors: 15-30 cm (6-12 inches)
Spread Indoors: 15-30 cm (6-12 inches)
Growth Rate Moderate
Growth Pattern Ornamental kale grows in a rosette shape, forming a dense cluster of leaves. It does not typically spread aggressively and maintains a compact form.

Soapwort

Height 30-90 cm (outdoors); significantly smaller if grown in a container indoors, likely 30-45cm
Spread Spreads via rhizomes, can become invasive. Outdoors: 30-60cm. Indoors in a pot: limited by pot size, but still spreads.
Growth Rate Fast
Growth Pattern Soapwort grows upright with branching stems. It spreads via rhizomes, forming clumps that can become quite dense over time.

🌱 Propagation — Comparing Plant Growth

Kale (Ornamental)

Methods: Seed

Difficulty: Easy

Tips: Sow seeds indoors 6-8 weeks before the last expected frost. Keep soil moist and provide adequate light. Transplant seedlings outdoors after the danger of frost has passed.

Soapwort

Methods: Seed, Division, Stem cuttings

Difficulty: Easy

Tips: Divide rhizomes in spring or fall. Take stem cuttings in late spring or early summer and root in water or moist soil. Seeds can be sown directly in the garden in spring or fall.

✨ Benefits & Features — Comparing Plant Value

Kale (Ornamental)

Ornamental kale is unique for its vibrant, non-traditional colors and frilly or ruffled leaves. Unlike edible kale, it is primarily grown for its aesthetic appeal. Its colors intensify in cooler temperatures, making it a popular choice for fall and winter gardens.

  • ✓ Adds vibrant color to gardens during cooler months.
  • ✓ Attracts beneficial insects.
  • ✓ Provides a unique visual element.
  • ✓ Relatively low-maintenance outdoors.
  • ✓ Can be used in cut flower arrangements.
  • ⚠️ Toxic to pets

Soapwort

Soapwort's unique characteristic is its saponin content, making it a natural soap substitute. Its historical use and ability to produce a lather set it apart from many other flowering perennials.

  • ✓ Attracts pollinators
  • ✓ Historically significant
  • ✓ Fragrant flowers
  • ✓ Low maintenance once established
  • ✓ Can be used for gentle cleaning
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Kale (Ornamental)

Repotting Not typically repotted as it is grown as an annual.
Pruning Remove yellowing or damaged leaves to maintain appearance and prevent disease.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 2-4 weeks during the growing season.
Seasonal Care In winter, protect from extreme cold. In summer, provide shade during the hottest part of the day. Ornamental kale thrives in cooler temperatures.

Soapwort

Repotting If grown in a container, repot every 1-2 years to refresh the soil and control spread.
Pruning Deadhead spent flowers to encourage further blooming. Prune back aggressively if it starts to spread too much.
Fertilizing Balanced liquid fertilizer diluted to half strength, applied once in spring and once in early summer.
Seasonal Care In winter, the plant dies back to the ground. Mulch to protect the roots in colder climates. In summer, ensure adequate watering and monitor for pests.

🌞 Light Requirements

Kale (Ornamental)

Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for best color development.

Low light tolerant: ❌ No

Soapwort

Full sun to partial shade

Low light tolerant: ❌ No

💧 Watering Needs

Kale (Ornamental)

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Ensure good drainage. Signs of underwatering include wilting leaves; overwatering includes yellowing leaves and a soggy soil.

Soapwort

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Signs of overwatering include yellowing leaves and a soggy soil. Underwatering is indicated by wilting leaves.

🌡️ Temperature & Humidity

Kale (Ornamental)

Temperature: 10-18°C

Humidity: 40-60%

Soapwort

Temperature: 15-25°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Kale (Ornamental)

Kale (Ornamental)

Brassica oleracea var. sabellica
Care: Expert Time: 5-10 minutes weekly Beginner: No

Gardeners looking to add color to their fall and winter gardens in cooler climates.

✅ Choose This Plant If...

  • You want vibrant color in your fall and winter garden.
  • You live in a cooler climate where it thrives.
  • You enjoy unique and visually striking foliage.
  • You are looking for a low-maintenance outdoor plant for seasonal displays.
  • You want to attract beneficial insects to your garden.

❌ Skip This Plant If...

  • You live in a hot climate where it will struggle.
  • You are looking for an easy indoor plant.
  • You have pets that might ingest it.
  • You prefer edible kale varieties for culinary purposes.
📍 Ideal Location: Outdoors in a sunny garden bed or container.
🎨 Style: Cottagecore, Rustic, Seasonal
🏠 Apartment Friendly: Limited
⚠️ Ornamental kale contains glucosinolates, which can cause gastrointestinal upset in dogs, cats, and horses if ingested in large quantities. Symptoms include vomiting, diarrhea, and abdominal pain. All parts of the plant are potentially toxic.
Soapwort

Soapwort

Saponaria officinalis
Care: Expert Time: 15 minutes weekly (weeding, deadheading) Beginner: No

Gardeners looking for a low-maintenance, historically interesting plant for their outdoor garden.

✅ Choose This Plant If...

  • You want a plant with a rich history of practical use.
  • You appreciate fragrant, pink or white flowers in your garden.
  • You need a low-maintenance perennial for a sunny location.
  • You want to attract pollinators to your garden.
  • You are interested in plants with natural saponins for gentle cleaning.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You have limited space and don't want a potentially invasive plant.
  • You are looking for a plant that thrives indoors.
📍 Ideal Location: Outdoor garden, herb garden, or sunny border
🎨 Style: Cottage garden, Traditional
🏠 Apartment Friendly: No
⚠️ All parts of the plant, especially the roots, contain saponins which are toxic to dogs, cats, and horses. Symptoms include vomiting, diarrhea, and irritation of the mouth and throat. According to the ASPCA, it can cause gastrointestinal upset.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

📈

Kale (Ornamental) has moderate growth, while Soapwort grows fast.

💡 Pro Tips For Comparing These Plants

Kale (Ornamental) Care Tips

Ornamental kale is primarily an outdoor plant and requires specific conditions to thrive indoors. Providing sufficient light and cool temperatures is crucial. Indoor growth is often less vibrant and shorter-lived than outdoor growth. Requires vigilant monitoring for pests and diseases.

  • Provide at least 6 hours of direct sunlight daily for best color development.
  • Water thoroughly when the top inch of soil feels dry.
  • Fertilize every 2-4 weeks during the growing season with a balanced liquid fertilizer.
  • Protect from extreme cold in winter.
  • Remove yellowing or damaged leaves to prevent disease.
❄️ Winter: Protect from extreme cold by covering with a frost blanket or moving to a sheltered location. Reduce watering frequency during periods of dormancy.
☀️ Summer: Provide shade during the hottest part of the day to prevent scorching. Ensure adequate watering to prevent wilting. Monitor for pests and diseases, which can be more prevalent in warmer weather.

Soapwort Care Tips

Soapwort is primarily an outdoor plant and will struggle indoors due to its high light requirements and tendency to spread. It needs full sun and well-draining soil. Indoor cultivation is challenging and requires careful attention to light, watering, and containment to prevent it from becoming invasive.

  • Plant in well-draining soil to prevent root rot.
  • Provide full sun for best flowering.
  • Deadhead spent flowers to encourage more blooms.
  • Monitor for aphids and treat promptly.
  • Control spread by planting in a container or using barriers.
❄️ Winter: Cut back the plant to the ground in late fall. Mulch around the base to protect the roots from freezing temperatures.
☀️ Summer: Water regularly during dry spells. Monitor for pests and diseases. Deadhead spent flowers to encourage continued blooming.

⚠️ Common Problems & Solutions — Plant Care Comparison

Kale (Ornamental)

Common Issues: Aphids, Cabbage White Butterfly caterpillars, Root rot, Powdery mildew
Solutions: Aphids: Insecticidal soap or neem oil. Cabbage White Butterfly caterpillars: Handpick caterpillars or use Bacillus thuringiensis (Bt). Root rot: Ensure good drainage and avoid overwatering. Powdery mildew: Improve air circulation and apply a fungicide.

Soapwort

Common Issues: Root rot, Powdery mildew, Aphids, Invasive spread
Solutions: Ensure well-draining soil and avoid overwatering to prevent root rot. Improve air circulation and treat with fungicide for powdery mildew. Control aphids with insecticidal soap. Contain spread by planting in a pot or using barriers.

❓ Frequently Asked Questions — Comparing These Plants

Kale (Ornamental)

What are the light requirements for Kale (Ornamental)?

Ornamental kale needs at least 6 hours of direct sunlight per day to develop its best color. In hotter climates, providing some afternoon shade can prevent the leaves from scorching. If growing indoors, place near a south-facing window or supplement with grow lights. Insufficient light can result in leggy growth and faded colors. Rotate the plant regularly to ensure even light exposure on all sides. If the plant is not getting enough light, the colors will be less intense and the leaves may turn more green than purple or pink.

How do I care for Kale (Ornamental)?

Ornamental kale thrives in cool weather and requires full sun to partial shade. Plant in well-draining soil with a slightly acidic to neutral pH. Water regularly, keeping the soil consistently moist but not waterlogged, especially during dry periods. Fertilize every 2-3 weeks with a balanced liquid fertilizer diluted to half strength, especially during the growing season to encourage vibrant colors. Deadhead any fading or damaged leaves to maintain a tidy appearance and promote new growth. Protect from extreme cold and frost, as this can damage the foliage. Mulch around the base of the plant to retain moisture and suppress weeds. Monitor for pests such as aphids and cabbage worms, and treat accordingly with insecticidal soap or neem oil.

How do I propagate Kale (Ornamental)?

Ornamental kale is typically grown from seed, but it can also be propagated by stem cuttings.

Soapwort

What are the light requirements for Soapwort?

Soapwort requires at least six hours of direct sunlight per day to thrive and produce abundant blooms. Insufficient light can lead to leggy growth and reduced flowering. An east- or south-facing window is ideal for indoor cultivation. If natural light is insufficient, supplement with grow lights. Rotate the plant regularly to ensure even light exposure on all sides. During the summer months, consider moving outdoor container plants to a location with full sun. Monitor the leaves for signs of sunburn (scorched spots) if exposed to intense afternoon sun, and adjust placement accordingly.

How do I care for Soapwort?

Soapwort thrives in well-draining soil and requires ample sunlight, ideally six or more hours per day. Water thoroughly when the top inch of soil feels dry to the touch, avoiding overwatering, which can lead to root rot. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer, diluted to half strength, to encourage abundant blooms. Prune spent flowers regularly to promote continuous blooming. Soapwort is relatively pest-resistant but monitor for aphids and spider mites, treating as needed with insecticidal soap. Provide good air circulation to prevent fungal diseases. In colder climates, provide winter protection or grow in containers that can be moved indoors. Repot every 2-3 years in spring.

How do I propagate Soapwort?

Soapwort can be easily propagated through division, stem cuttings, or from seed.

Last updated: April 27, 2026 — Plant care data reviewed and verified by our editorial team.