Horehound vs Purple Fountain Grass Plant Comparison

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

Horehound

Horehound

Marrubium vulgare

VS
Purple Fountain Grass

Purple Fountain Grass

Pennisetum setaceum 'Rubrum'

Horehound

Horehound

Marrubium vulgare

Horehound is a perennial herbaceous plant known for its wrinkled, grayish-green leaves and square stems, typical of the mint family. It grows to about 25-45 cm tall. While it can be grown indoors, it thrives outdoors in well-drained soil and full sun. It's cultivated for its medicinal properties, particularly for cough remedies and digestive aids. The plant produces small, white flowers clustered in the leaf axils. Its aromatic foliage is also used in herbal teas and candies.

Lamiaceae Europe, North Africa, and Asia; naturalized in North and South America
✨ Features: Medicinal properties, aromatic foliage, attracts pollinators
📖 Read Complete Horehound Guide
Purple Fountain Grass

Purple Fountain Grass

Pennisetum setaceum 'Rubrum'

Purple Fountain Grass is a striking ornamental grass prized for its arching, burgundy-purple foliage and bottlebrush-like flower plumes. It typically grows in a mounded form, reaching several feet in height and width. While technically a perennial in warmer climates, it is often grown as an annual in cooler regions due to its sensitivity to frost. It is primarily an outdoor plant, grown for its dramatic texture and color in gardens and landscapes. People grow it for its ornamental value, adding movement and visual interest to borders, containers, and mass plantings.

Poaceae Hybrid cultivar; species native to Africa, Southwest Asia
✨ Features: Attractive foliage and flower plumes, drought tolerance, deer resistance
📖 Read Complete Purple Fountain Grass Guide

Quick Plant Comparison

Feature Horehound Purple Fountain Grass
Light Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth. Full sun (at least 6 hours of direct sunlight per day)
Watering Every 1-2 weeks, depending on environmental conditions and soil drainage. Every 7-10 days, depending on weather and soil drainage
Humidity 30-50% 20-50%
Temperature 15-25°C 18-30°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height 25-45 cm (indoors, may be smaller) Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters
Pet Safety ❌ Toxic To Pets ✅ Safe
Soil Well-drained, sandy or loamy soil. A mix of potting soil, perlite, and sand is suitable. Well-draining soil, such as a sandy loam or a potting mix amended with perlite
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Horehound

Scientific Name Marrubium vulgare
Family Lamiaceae
Native To Europe, North Africa, and Asia; naturalized in North and South America
Also Known As Horehound, White Horehound, Common Horehound
Leaves The leaves are ovate to round, 2-5 cm long, and have a wrinkled, grayish-green appearance due to a covering of fine hairs. The leaf margins are crenate (scalloped). The texture is slightly woolly to the touch.
Flowers Horehound produces small, white flowers in dense clusters (whorls) at the leaf axils. Flowering typically occurs in summer (June-August). It is unlikely to flower indoors unless provided with very intense light.

Purple Fountain Grass

Scientific Name Pennisetum setaceum 'Rubrum'
Family Poaceae
Native To Hybrid cultivar; species native to Africa, Southwest Asia
Also Known As Purple Fountain Grass, Red Fountain Grass
Leaves The leaves are long, narrow, and arching, with a deep burgundy-purple color. They have a fine texture and create a graceful, flowing appearance.
Flowers It produces bottlebrush-like flower plumes that are initially a deep burgundy-purple, fading to a tan color as they mature. Flowering typically occurs in summer and fall. It is unlikely to flower indoors.

📏 Size & Growth — Plant Comparison

Horehound

Height 25-45 cm (indoors, may be smaller)
Spread 30-60 cm
Growth Rate Moderate
Growth Pattern Horehound grows as an upright, bushy perennial. It has a spreading habit, but is not considered aggressively invasive. It forms a dense clump of stems and foliage.

Purple Fountain Grass

Height Outdoor: 0.6-1.5 meters. Indoor (unlikely to thrive): 0.3-0.6 meters
Spread Outdoor: 0.6-1.2 meters. Indoor (unlikely to thrive): 0.3-0.6 meters
Growth Rate Moderate
Growth Pattern Grows in a mounded, upright form with arching foliage and flower plumes.

🌱 Propagation — Comparing Plant Growth

Horehound

Methods: Seed, stem cuttings, division

Difficulty: Easy

Tips: For stem cuttings, take 4-6 inch cuttings in spring or summer, remove lower leaves, and root in water or moist soil. For division, separate the plant at the roots in spring or fall. Seeds can be sown directly in the garden in spring or fall.

Purple Fountain Grass

Methods: Seed, Division

Difficulty: Moderate

Tips: Divide clumps in spring or early summer. Sow seeds indoors 6-8 weeks before the last frost.

✨ Benefits & Features — Comparing Plant Value

Horehound

Horehound is known for its medicinal properties, particularly its use as an expectorant and cough suppressant. Its bitter taste is due to the presence of marrubiin, a diterpene compound. The plant's woolly texture and grayish-green foliage also distinguish it from other mint family members.

  • ✓ Provides medicinal benefits for coughs and respiratory ailments.
  • ✓ Attracts pollinators like bees and butterflies to the garden.
  • ✓ Adds an aromatic element to the garden.
  • ✓ Can be used in herbal teas and candies.
  • ✓ Offers a visually appealing texture and color to the landscape.
  • ⚠️ Toxic to pets

Purple Fountain Grass

Its deep purple foliage and graceful, arching habit make it a standout in any garden. The bottlebrush-like flower plumes add further visual interest and movement.

  • ✓ Adds visual interest and texture to the garden
  • ✓ Attracts birds
  • ✓ Drought tolerant
  • ✓ Deer resistant
  • ✓ Provides movement in the landscape
  • 🐾 Pet Safe

📅 Maintenance Schedule — Plant Care Comparison

Horehound

Repotting Repot every 1-2 years in spring, or as needed if the plant becomes root-bound.
Pruning Prune regularly to maintain shape and encourage bushier growth. Remove spent flowers to prevent self-seeding.
Fertilizing Balanced liquid fertilizer diluted to half strength. Apply every 4-6 weeks during the growing season (spring and summer).
Seasonal Care In winter, reduce watering and provide protection from frost if grown in colder climates. In summer, ensure adequate sunlight and water regularly.

Purple Fountain Grass

Repotting Not applicable as it is primarily an outdoor plant. If grown in a container, repot every 1-2 years in spring.
Pruning Cut back dead or damaged foliage as needed. Prune lightly in early spring to encourage new growth.
Fertilizing Balanced slow-release fertilizer in spring; liquid fertilizer diluted to half strength monthly during the growing season
Seasonal Care In colder climates, cut back foliage in late fall after it has turned brown. In warmer climates, prune lightly in early spring to remove dead or damaged growth. Reduce watering in winter.

🌞 Light Requirements

Horehound

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

Low light tolerant: ❌ No

Purple Fountain Grass

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

Low light tolerant: ❌ No

💧 Watering Needs

Horehound

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, as it can lead to root rot. Ensure good drainage. Signs of overwatering include yellowing leaves and a musty smell. Underwatering is indicated by wilting and dry, crispy leaves.

Purple Fountain Grass

Water deeply when the top inch of soil feels dry to the touch. Avoid overwatering, which can lead to root rot. Signs of underwatering include drooping or browning leaves. Signs of overwatering include yellowing leaves and soggy soil.

🌡️ Temperature & Humidity

Horehound

Temperature: 15-25°C

Humidity: 30-50%

Purple Fountain Grass

Temperature: 18-30°C

Humidity: 20-50%

🤔 Which Plant Is Right For You?

Horehound

Horehound

Marrubium vulgare
Care: Expert Time: 15 minutes weekly Beginner: No

Experienced gardeners looking for a medicinal herb to grow outdoors.

✅ Choose This Plant If...

  • You want a plant with medicinal properties for cough relief.
  • You enjoy growing aromatic herbs in your garden.
  • You want to attract pollinators to your outdoor space.
  • You have a sunny, well-drained garden spot.
  • You are an experienced gardener looking for a new challenge.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You lack a sunny outdoor space.
  • You are a beginner gardener.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Sunny garden or herb garden
🎨 Style: Cottage, Herb Garden, Rustic
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Horehound contains compounds that can be toxic to dogs, cats, and horses. Symptoms include gastrointestinal upset (vomiting, diarrhea), weakness, and potentially heart problems if ingested in large quantities. All parts of the plant are considered toxic.
Purple Fountain Grass

Purple Fountain Grass

Pennisetum setaceum 'Rubrum'
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners looking for a dramatic ornamental grass to add color and texture to their landscape.

✅ Choose This Plant If...

  • You want a striking focal point in your garden.
  • You need a drought-tolerant plant for a sunny location.
  • You desire a plant with beautiful purple foliage and plumes.
  • You want to attract birds to your garden.
  • You need a deer-resistant plant.

❌ Skip This Plant If...

  • You live in a cold climate and don't want to treat it as an annual.
  • You don't have a sunny location.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Outdoor garden, sunny border, container on a patio
🎨 Style: Modern, Mediterranean, Southwestern, Cottage
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Pennisetum species are generally considered non-toxic to dogs, cats, and horses.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Purple Fountain Grass ✓
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

Horehound Care Tips

Horehound is best suited for outdoor cultivation due to its high light requirements. Indoor growing is challenging and requires very bright light, excellent drainage, and careful watering. It is toxic to pets, so keep it out of reach. Regular pruning is needed to maintain shape.

  • Provide at least 6 hours of direct sunlight daily for optimal growth.
  • Ensure well-draining soil to prevent root rot.
  • Prune regularly to maintain shape and encourage bushier growth.
  • Harvest leaves in the morning for the best flavor and medicinal properties.
  • Protect from frost in colder climates.
❄️ Winter: In winter, reduce watering significantly. If grown outdoors in colder climates, provide mulch around the base of the plant for insulation. Dormancy is normal during winter.
☀️ Summer: In summer, ensure adequate sunlight and water regularly, especially during hot and dry periods. Harvest leaves for medicinal use or drying. Prune after flowering to encourage bushier growth.

Purple Fountain Grass Care Tips

Purple Fountain Grass is primarily an outdoor plant and will struggle indoors due to its high light requirements. It needs full sun and well-draining soil. While it can be grown in containers, it requires regular watering and fertilization. Overwintering indoors is possible in colder climates, but the plant may not thrive.

  • Plant in well-draining soil in a sunny location.
  • Water deeply but infrequently, allowing the soil to dry out between waterings.
  • Fertilize in spring with a balanced slow-release fertilizer.
  • Cut back foliage in late fall or early spring.
  • Protect from frost in colder climates.
❄️ Winter: In cold climates, cut back foliage after it turns brown. Reduce watering significantly. If overwintering indoors, provide as much light as possible and keep soil slightly moist.
☀️ Summer: Water more frequently during hot, dry weather. Fertilize monthly with a diluted liquid fertilizer to promote growth and flowering.

⚠️ Common Problems & Solutions — Plant Care Comparison

Horehound

Common Issues: Root rot, powdery mildew, aphids
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Powdery mildew: Improve air circulation and treat with a fungicide. Aphids: Spray with insecticidal soap or neem oil.

Purple Fountain Grass

Common Issues: Root rot, Aphids, Spider mites, Leaf spot
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Aphids: Spray with insecticidal soap. Spider mites: Increase humidity and treat with miticide. Leaf spot: Remove affected leaves and apply fungicide.

❓ Frequently Asked Questions — Comparing These Plants

Horehound

What are the light requirements for Horehound?

Horehound requires at least 6-8 hours of direct sunlight per day to thrive. Insufficient light can lead to leggy growth and reduced flowering. When growing indoors, place Horehound near a sunny window, preferably south-facing. If natural light is insufficient, supplement with artificial grow lights. Rotate the plant regularly to ensure even light exposure on all sides. Outdoor plants should be positioned in a location that receives full sun throughout the day. Shaded areas can result in weak, spindly growth. Consider the intensity of the sunlight in your region when selecting a planting location. In hotter climates, some afternoon shade may be beneficial.

How do I care for Horehound?

Horehound thrives in well-draining soil and requires full sun for optimal growth and flowering. Water thoroughly when the top inch of soil feels dry, but avoid overwatering, as this can lead to root rot. Fertilize lightly in the spring with a balanced fertilizer to encourage healthy growth and abundant blooms. Prune regularly to maintain a compact shape and promote bushier growth. Horehound is relatively drought-tolerant once established. Ensure good air circulation to prevent fungal diseases. Protect from frost in colder climates by providing a sheltered location or bringing potted plants indoors. Monitor for pests such as aphids and spider mites and treat accordingly. A pH level of 6.5 to 7.5 is ideal for Horehound. Regularly check the soil quality and adjust as needed. Provide adequate spacing between plants to ensure good air circulation and prevent overcrowding.

How do I propagate Horehound?

Horehound can be propagated easily through stem cuttings. Take 4-6 inch cuttings from healthy stems. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in well-draining potting mix. Keep the soil moist and provide indirect light. Roots should develop within a few weeks. Alternatively, Horehound can be propagated by division. Carefully dig up the plant and separate the root ball into smaller sections. Replant each section in its own pot or in the garden. Horehound does not produce keiki.

Purple Fountain Grass

What are the light requirements for Purple Fountain Grass?

Purple Fountain Grass requires at least 6-8 hours of direct sunlight per day to thrive and develop its characteristic vibrant purple foliage and abundant flower plumes. Insufficient sunlight can lead to leggy growth, faded color, and reduced flowering. When planting, choose a location that receives full sun throughout the day. If growing in containers, rotate the plant regularly to ensure even sun exposure on all sides. In hotter climates, some afternoon shade may be beneficial to prevent scorching, but avoid placing it in deep shade, which will hinder its growth. Supplemental lighting may be necessary if grown indoors during winter months.

How do I care for Purple Fountain Grass?

Purple Fountain Grass thrives in full sun and well-draining soil. Water thoroughly when the top inch of soil feels dry, but avoid overwatering, which can lead to root rot. Fertilize monthly during the growing season (spring and summer) with a balanced fertilizer to promote healthy growth and vibrant blooms. Prune away dead or damaged foliage in late winter or early spring before new growth emerges. In colder climates, treat it as an annual or bring it indoors during the winter. Provide adequate air circulation to prevent fungal diseases. Regularly inspect for pests like aphids or spider mites, and treat accordingly. Avoid planting in overly compacted or poorly draining soil. Mulching around the base can help retain moisture and suppress weeds. Protect from strong winds.

How do I propagate Purple Fountain Grass?

Purple Fountain Grass can be propagated by division. In early spring, carefully dig up the plant and divide the root ball into smaller clumps, ensuring each clump has healthy roots and foliage. Replant the divisions in well-draining soil and water thoroughly. Keep the soil consistently moist until the new plants are established. Division is the most reliable method. Seed propagation is possible but can be inconsistent in producing plants true to the ‘Rubrum’ cultivar. Stem cuttings are not typically used for propagating this grass. Keikis are not applicable as this plant doesn’t produce them. Ensure good air circulation to prevent fungal diseases after dividing.

Last updated: April 22, 2026 — Plant care data reviewed and verified by our editorial team.