Key Lime vs Lysimachia Plant Comparison

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

Key Lime

Key Lime

Citrus aurantiifolia

VS
Lysimachia

Lysimachia

Lysimachia nummularia

Key Lime

Key Lime

Citrus aurantiifolia

The Key Lime is a small, thorny citrus tree typically reaching 6-13 feet in height. It produces small, highly aromatic limes with a thin, greenish-yellow rind. The pulp is juicy and acidic. Key Limes are primarily grown outdoors in warm climates for their fruit, which is used in pies, beverages, and other culinary applications. While it can be grown in containers, replicating its ideal outdoor conditions indoors is challenging. It is not naturally an indoor plant.

Rutaceae Southeast Asia
✨ Features: Aromatic foliage and fruit, used in culinary applications.
📖 Read Complete Key Lime Guide
Lysimachia

Lysimachia

Lysimachia nummularia

Lysimachia nummularia, commonly known as Creeping Jenny or Moneywort, is a perennial ground cover characterized by its trailing stems and rounded, coin-like leaves. It typically grows to only a few inches in height but can spread extensively. While primarily an outdoor plant, it is sometimes grown in hanging baskets or containers indoors. People grow it for its attractive foliage and ability to quickly cover ground, creating a lush, green carpet. Its vibrant green or golden foliage adds visual interest to gardens and landscapes. It is not ideally suited for long-term indoor growth.

Primulaceae Europe
✨ Features: Attractive foliage, ground cover, erosion control.
📖 Read Complete Lysimachia Guide

Quick Plant Comparison

Feature Key Lime Lysimachia
Light Full sun (6-8 hours of direct sunlight daily) Full sun to partial shade outdoors. Indoors, requires very bright, direct light for several hours daily.
Watering Every 1-2 weeks, depending on environmental conditions and pot size. Every 3-7 days, depending on light and temperature.
Humidity 50-70% 30-50%
Temperature 21-32°C 15-24°C
Care Level Expert Expert
Growth Rate Moderate Fast
Max Height 2-4 meters outdoors, 1-2 meters in containers indoors (with difficulty) 2-10 cm (indoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining citrus potting mix Well-draining potting mix or garden soil.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes weekly 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Key Lime

Scientific Name Citrus aurantiifolia
Family Rutaceae
Native To Southeast Asia
Also Known As Key Lime, Mexican Lime, West Indian Lime
Leaves The leaves are small, oval-shaped, and glossy green. They are aromatic when crushed.
Flowers Key Limes produce small, white, fragrant flowers in spring. They can flower indoors with sufficient light, but fruiting is rare.

Lysimachia

Scientific Name Lysimachia nummularia
Family Primulaceae
Native To Europe
Also Known As Creeping Jenny, Moneywort, Twopenny Grass
Leaves Rounded, coin-like leaves that are typically bright green, but some varieties have golden or chartreuse foliage. Leaves are small, usually less than an inch in diameter, and have a smooth texture.
Flowers It may produce small, yellow, cup-shaped flowers in the summer, but flowering is rare indoors.

📏 Size & Growth — Plant Comparison

Key Lime

Height 2-4 meters outdoors, 1-2 meters in containers indoors (with difficulty)
Spread 2-3 meters outdoors, 0.5-1 meter in containers indoors
Growth Rate Moderate
Growth Pattern The Key Lime tree is a small, shrubby tree with a rounded crown. It has thorny branches and a tendency to sucker from the base.

Lysimachia

Height 2-10 cm (indoors)
Spread 30-60 cm (indoors, can be aggressive in ideal conditions)
Growth Rate Fast
Growth Pattern Trailing, spreading ground cover. Stems can grow long and cascade over edges of containers or spread across the ground.

🌱 Propagation — Comparing Plant Growth

Key Lime

Methods: Seed, grafting, air layering, cuttings

Difficulty: Moderate

Tips: Use rooting hormone for cuttings and provide high humidity. Grafting is the most reliable method for fruit production.

Lysimachia

Methods: Stem cuttings, Division

Difficulty: Easy

Tips: Take stem cuttings and place them in water or directly into moist soil. Keep the soil consistently moist until roots develop. Division can be done by separating rooted sections of the plant.

✨ Benefits & Features — Comparing Plant Value

Key Lime

Key Limes are smaller and more acidic than Persian limes. They have a distinctive aroma and are a key ingredient in Key Lime pie.

  • ✓ Provides fresh limes for culinary use.
  • ✓ Aromatic foliage adds a pleasant scent to the garden.
  • ✓ Can be a rewarding challenge for experienced gardeners.
  • ✓ Offers a taste of the tropics in your own backyard.
  • ✓ The fruit is a good source of Vitamin C.
  • ⚠️ Toxic to pets

Lysimachia

Its trailing growth habit and coin-shaped leaves make it a unique and attractive ground cover. It can tolerate a range of soil conditions and is relatively easy to propagate.

  • ✓ Provides ground cover and helps prevent soil erosion.
  • ✓ Adds visual interest with its bright green or golden foliage.
  • ✓ Can be used in hanging baskets or containers.
  • ✓ Relatively easy to propagate.
  • ✓ Can tolerate a range of soil conditions.
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Key Lime

Repotting Every 2-3 years, or when the plant becomes root-bound.
Pruning Prune to maintain shape and remove dead or crossing branches. Prune after fruiting.
Fertilizing Citrus-specific fertilizer, diluted to half strength, every 4-6 weeks during the growing season (spring and summer)
Seasonal Care In winter, reduce watering and provide supplemental light if needed. Protect from frost. In summer, water more frequently and fertilize regularly.

Lysimachia

Repotting Every 1-2 years, or as needed if the plant becomes root-bound. More frequently if growth is vigorous.
Pruning Regular pruning is necessary to control its spread and maintain its shape. Prune back stems that become too long or leggy.
Fertilizing Balanced liquid fertilizer diluted to half strength, every 4-6 weeks during the growing season (spring/summer).
Seasonal Care In winter, reduce watering and provide adequate light. In summer, ensure adequate moisture and protection from intense afternoon sun.

🌞 Light Requirements

Key Lime

Full sun (6-8 hours of direct sunlight daily)

Low light tolerant: ❌ No

Lysimachia

Full sun to partial shade outdoors. Indoors, requires very bright, direct light for several hours daily.

Low light tolerant: ❌ No

💧 Watering Needs

Key Lime

Water thoroughly when the top inch of soil is dry. Overwatering can lead to root rot, indicated by yellowing leaves and a musty smell. Underwatering results in wilting and leaf drop. Ensure good drainage.

Lysimachia

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, as it can lead to root rot. Signs of underwatering include wilting leaves. Signs of overwatering include yellowing leaves and soggy soil.

🌡️ Temperature & Humidity

Key Lime

Temperature: 21-32°C

Humidity: 50-70%

Lysimachia

Temperature: 15-24°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Key Lime

Key Lime

Citrus aurantiifolia
Care: Expert Time: 30 minutes weekly Beginner: No

Experienced gardeners in warm climates who want to grow their own limes.

✅ Choose This Plant If...

  • You live in a warm climate and can provide ample sunlight.
  • You enjoy the challenge of growing citrus trees.
  • You want to harvest your own Key Limes for cooking and baking.
  • You have a greenhouse or conservatory where you can control the environment.
  • You are willing to provide supplemental lighting and humidity indoors.

❌ Skip This Plant If...

  • You live in a cold climate with limited sunlight.
  • You are a beginner gardener.
  • You do not have the space or resources to provide the necessary care.
  • You have pets that may be poisoned by the plant.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Outdoors in a sunny location. Indoors, a south-facing window with supplemental lighting.
🎨 Style: Tropical, Mediterranean
🏠 Apartment Friendly: Limited
⚠️ According to the ASPCA, citrus plants contain psoralens and essential oils that can cause gastrointestinal upset and dermatitis in dogs, cats, and horses. Symptoms include vomiting, diarrhea, drooling, and skin irritation.
Lysimachia

Lysimachia

Lysimachia nummularia
Care: Expert Time: 15 minutes weekly Beginner: No

Experienced gardeners looking for a ground cover for outdoor spaces or those willing to provide very bright light and manage its growth indoors.

✅ Choose This Plant If...

  • You want a fast-growing ground cover for your garden.
  • You have a very bright, sunny indoor space.
  • You enjoy the look of trailing foliage in hanging baskets.
  • You want a plant that is relatively easy to propagate.
  • You are experienced with managing potentially aggressive plants.

❌ Skip This Plant If...

  • You have pets that may ingest the plant.
  • You have limited sunlight indoors.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Outdoors in a garden or hanging basket. Indoors, a sunny windowsill or under grow lights.
🎨 Style: Cottagecore, Bohemian, Naturalistic
🏠 Apartment Friendly: Limited
⚠️ According to the ASPCA, Lysimachia is toxic to dogs, cats, and horses. Symptoms include vomiting and diarrhea. All parts of the plant are considered toxic.

🎯 Quick Verdict

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

⚡ Key Differences Between These Plants

📈

Key Lime has moderate growth, while Lysimachia grows fast.

💡 Pro Tips For Comparing These Plants

Key Lime Care Tips

Key Limes are challenging to grow indoors due to their high light and humidity requirements. They need very bright light, consistent watering, and protection from drafts. Fruit production indoors is unlikely without significant effort and supplemental lighting. Requires careful monitoring to prevent pests and diseases.

  • Provide well-draining soil to prevent root rot.
  • Water deeply but infrequently, allowing the soil to dry slightly between waterings.
  • Fertilize regularly during the growing season with a citrus-specific fertilizer.
  • Protect from frost and cold temperatures.
  • Prune regularly to maintain shape and remove dead or diseased branches.
❄️ Winter: Reduce watering frequency. Protect from frost. Provide supplemental light if needed.
☀️ Summer: Water more frequently. Fertilize regularly. Protect from intense afternoon sun in very hot climates.

Lysimachia Care Tips

Creeping Jenny is relatively easy to care for outdoors, but it can be challenging indoors due to its high light requirements and potential for aggressive growth. It needs very bright light and well-draining soil. Overwatering is a common problem. Regular pruning is needed to control its spread.

  • Provide bright, indirect light with some direct sun exposure.
  • Water thoroughly when the top inch of soil feels dry, but avoid overwatering.
  • Fertilize regularly during the growing season.
  • Prune regularly to control its spread and maintain its shape.
  • Monitor for pests and treat promptly.
❄️ Winter: Reduce watering frequency during the winter months. Ensure the plant receives adequate light, even during shorter days. Protect from frost if grown outdoors.
☀️ Summer: Provide adequate moisture during the hot summer months. Protect from intense afternoon sun to prevent leaf scorch. Fertilize regularly to support growth.

⚠️ Common Problems & Solutions — Plant Care Comparison

Key Lime

Common Issues: Spider mites, scale, aphids, root rot
Solutions: Spider mites: Increase humidity and use insecticidal soap. Scale: Manually remove and treat with horticultural oil. Aphids: Wash off with water or use insecticidal soap. Root rot: Improve drainage and reduce watering frequency.

Lysimachia

Common Issues: Root rot, Leggy growth, Pest infestations (spider mites, aphids), Yellowing leaves
Solutions: Root rot: Improve drainage and reduce watering frequency. | Leggy growth: Provide more light and prune back stems. | Pest infestations: Treat with insecticidal soap or neem oil. | Yellowing leaves: Check for overwatering or nutrient deficiencies.

❓ Frequently Asked Questions — Comparing These Plants

Key Lime

What are the light requirements for Key Lime?

Key Lime trees demand bright, direct sunlight to flourish indoors. Ideally, place your tree near a south-facing window where it can receive at least 6-8 hours of sunlight daily. If natural light is insufficient, supplement with grow lights. Rotate the tree regularly to ensure even light exposure on all sides, preventing lopsided growth. Insufficient light can lead to leggy growth, reduced flowering, and poor fruit production. Consider using a light meter to measure the intensity of light reaching your tree. For optimal growth, aim for a light intensity of at least 2,000 foot-candles.

How do I care for Key Lime?

Key Lime trees thrive with bright light, ideally 6-8 hours of direct sunlight or equivalent grow lights. Water thoroughly when the top inch of soil feels dry, allowing excess water to drain. Use well-draining potting mix specifically formulated for citrus trees. Fertilize monthly during the growing season (spring and summer) with a citrus-specific fertilizer. Prune regularly to maintain shape and encourage fruiting. Provide adequate humidity by misting regularly or using a humidifier. Protect from drafts and sudden temperature changes. Repot every 2-3 years into a slightly larger pot. Monitor for pests like spider mites or scale and treat promptly. Ensure stable conditions and avoid overwatering. Proper pot size is crucial to prevent root rot.

How do I propagate Key Lime?

Key Lime trees can be propagated through stem cuttings or air layering. For stem cuttings, take a 4-6 inch cutting from new growth. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cutting in a well-draining potting mix and keep it moist. Cover with a plastic bag to maintain humidity. Roots should develop in 4-6 weeks. For air layering, make a small incision on a branch and wrap it with moist sphagnum moss. Cover the moss with plastic wrap and secure it with tape. After several weeks, roots will form in the moss. Cut the branch below the roots and plant it in a pot. Provide warm temperatures and bright, indirect light during propagation. Ensure stable conditions and monitor moisture levels.

Lysimachia

What are the light requirements for Lysimachia?

Lysimachia prefers partial to full sunlight, though the specific light needs vary depending on the species. Generally, plants need at least 4-6 hours of direct sunlight per day to thrive and produce abundant blooms. In hotter climates, providing some afternoon shade can prevent leaf scorch. Insufficient light can result in leggy growth, reduced flowering, and pale foliage.

How do I care for Lysimachia?

Lysimachia thrives in moist, well-draining soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Plant in a location that receives partial to full sunlight, depending on the specific species. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer to encourage blooming. Prune regularly to maintain shape and remove any dead or damaged foliage.

How do I propagate Lysimachia?

Lysimachia can be propagated easily through division, stem cuttings, and, in some species, keikis.

Last updated: April 24, 2026 — Plant care data reviewed and verified by our editorial team.