Locust Tree vs Speedwell Plant Comparison

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

Locust Tree

Locust Tree

Robinia pseudoacacia

VS
Speedwell

Speedwell

Veronica spp.

Locust Tree

Locust Tree

Robinia pseudoacacia

The Black Locust is a medium-sized deciduous tree, typically reaching 40-70 feet in height. It features a relatively straight trunk and an open, irregular crown. The bark is deeply furrowed and dark brown. Its leaves are pinnately compound, with oval leaflets. Black Locust is known for its fragrant, white, pea-like flowers that bloom in drooping clusters in late spring. It is primarily an outdoor tree, valued for its rapid growth, nitrogen-fixing capabilities, and durable wood. It is not suitable as an indoor plant.

Fabaceae Native to the southeastern United States, but widely naturalized throughout North America, Europe, and Asia.
✨ Features: Nitrogen-fixing capabilities, fragrant flowers, durable wood, attracts pollinators.
📖 Read Complete Locust Tree Guide
Speedwell

Speedwell

Veronica spp.

Speedwell encompasses a diverse genus of flowering plants, primarily herbaceous perennials, though some are annuals or shrubs. They exhibit a range of growth habits, from creeping groundcovers to upright forms. The flowers are typically small and blue, but can also be pink, white, or purple, arranged in spikes or racemes. Speedwell is primarily grown outdoors in gardens and meadows for its attractive flowers and ability to attract pollinators. While some species are relatively adaptable, they generally require specific outdoor conditions that are difficult to replicate indoors.

Plantaginaceae Europe, Asia, North Africa, North America
✨ Features: Attracts pollinators (bees, butterflies), deer-resistant (in some cases), long blooming period.
📖 Read Complete Speedwell Guide

Quick Plant Comparison

Feature Locust Tree Speedwell
Light Full sun Full sun to partial shade
Watering Water deeply 1-2 times per week for young trees; mature trees need less frequent watering, only during prolonged drought. Every 3-7 days, depending on weather and soil drainage
Humidity 30-50% 40-60%
Temperature 10-30°C 15-24°C
Care Level Expert Expert
Growth Rate Fast Moderate To Fast, Some Species Can Be Aggressive Spreaders
Max Height Not applicable for indoor growing. Outdoors: 40-70 feet (12-21 meters) 10-90 cm (outdoor)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-drained soil; adaptable to various soil types, including poor, sandy, and clay soils. Prefers slightly acidic to neutral pH. Well-draining, loamy soil
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes monthly (for young trees, more for mature trees needing pruning) 15 minutes weekly (outdoor)

🔬 Botanical Information — Comparing These Plants

Locust Tree

Scientific Name Robinia pseudoacacia
Family Fabaceae
Native To Native to the southeastern United States, but widely naturalized throughout North America, Europe, and Asia.
Also Known As Black Locust, False Acacia, Yellow Locust, Common Locust
Leaves The leaves are pinnately compound, typically 8-14 inches long, with 7-21 oval leaflets. The leaflets are smooth-edged, about 1-2 inches long, and dark green in color.
Flowers Black Locust rarely, if ever, flowers indoors. Outdoors, it produces fragrant, white, pea-like flowers in drooping clusters (racemes) in late spring (May-June). The flowers are highly attractive to bees and other pollinators.

Speedwell

Scientific Name Veronica spp.
Family Plantaginaceae
Native To Europe, Asia, North Africa, North America
Also Known As Speedwell, Gypsyweed, Bird's Eye
Leaves Leaves are typically small, oval or lance-shaped, and arranged oppositely or alternately along the stem. The color is usually green, but some varieties have variegated foliage.
Flowers Speedwell flowers outdoors in spring and summer. The flowers are small and typically blue, but can also be pink, white, or purple. They are arranged in spikes or racemes.

📏 Size & Growth — Plant Comparison

Locust Tree

Height Not applicable for indoor growing. Outdoors: 40-70 feet (12-21 meters)
Spread Not applicable for indoor growing. Outdoors: 20-40 feet (6-12 meters)
Growth Rate Fast
Growth Pattern Black Locust grows as an upright tree with a relatively straight trunk and an open, irregular crown. It can spread through root suckers, forming thickets if not managed.

Speedwell

Height 10-90 cm (outdoor)
Spread 15-60 cm (outdoor), spreads via rhizomes in some species
Growth Rate Moderate To Fast, Some Species Can Be Aggressive Spreaders
Growth Pattern Varies depending on the species. Some are creeping groundcovers, while others are upright and bushy. Some species spread via rhizomes, forming dense mats.

🌱 Propagation — Comparing Plant Growth

Locust Tree

Methods: Seed, Root cuttings, Suckers

Difficulty: Moderate

Tips: Seeds require scarification and stratification before sowing. Root cuttings should be taken in late winter or early spring. Suckers can be separated from the parent tree.

Speedwell

Methods: Stem cuttings, Division, Seed

Difficulty: Easy To Moderate

Tips: For stem cuttings, take cuttings in spring or summer and root them in water or moist soil. Division is best done in spring or fall. Sow seeds in spring after the last frost.

✨ Benefits & Features — Comparing Plant Value

Locust Tree

Black Locust is known for its nitrogen-fixing capabilities, which enrich the soil. Its wood is exceptionally durable and rot-resistant, making it valuable for various outdoor applications. The fragrant flowers attract pollinators, contributing to local biodiversity.

  • ✓ Erosion control
  • ✓ Nitrogen fixation
  • ✓ Durable wood source
  • ✓ Pollinator attraction
  • ✓ Shade provision
  • ⚠️ Toxic to pets

Speedwell

Speedwell is known for its long blooming period and ability to attract pollinators. The flowers come in a variety of colors, and the plant is relatively low-maintenance. Some species spread aggressively, making them useful as groundcovers.

  • ✓ Attracts pollinators
  • ✓ Provides long-lasting color in the garden
  • ✓ Deer-resistant
  • ✓ Relatively low-maintenance
  • ✓ Can be used as a groundcover
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Locust Tree

Repotting Not applicable as this is not an indoor plant.
Pruning Prune in late winter or early spring to remove dead, damaged, or crossing branches. Prune young trees to establish a strong central leader.
Fertilizing Young trees benefit from a balanced fertilizer (10-10-10) in early spring. Mature trees generally do not require fertilization unless nutrient deficiencies are observed.
Seasonal Care Spring: Fertilize young trees; Summer: Monitor for pests and diseases; Autumn: Collect seeds; Winter: Prune dormant trees.

Speedwell

Repotting Not applicable for indoor growing, but if grown in containers outdoors, repot every 2-3 years or as needed.
Pruning Deadhead spent flowers to encourage continued blooming. Prune back in late fall or early spring to maintain shape and size.
Fertilizing Balanced fertilizer (10-10-10) diluted to half strength, applied in spring and early summer
Seasonal Care In spring, fertilize and prune back dead growth. In summer, water regularly and deadhead spent flowers. In fall, divide plants if needed. In winter, provide mulch for protection in colder climates.

🌞 Light Requirements

Locust Tree

Full sun

Low light tolerant: ❌ No

Speedwell

Full sun to partial shade

Low light tolerant: ❌ No

💧 Watering Needs

Locust Tree

Young trees require regular watering to establish a strong root system. Mature trees are drought-tolerant but benefit from occasional deep watering during extended dry periods. Overwatering can lead to root rot, so ensure the soil is well-draining. Check soil moisture before watering.

Speedwell

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Speedwell prefers consistently moist, but not soggy, soil. In hotter weather, more frequent watering may be necessary. Reduce watering during dormancy.

🌡️ Temperature & Humidity

Locust Tree

Temperature: 10-30°C

Humidity: 30-50%

Speedwell

Temperature: 15-24°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Locust Tree

Locust Tree

Robinia pseudoacacia
Care: Expert Time: 30 minutes monthly (for young trees, more for mature trees needing pruning) Beginner: No

Landowners looking for a fast-growing tree for erosion control, nitrogen fixation, or timber production.

✅ Choose This Plant If...

  • You need a fast-growing tree for erosion control.
  • You want to improve soil fertility through nitrogen fixation.
  • You need a source of durable, rot-resistant wood.
  • You want to attract pollinators to your garden.
  • You have a large outdoor space with full sun.

❌ Skip This Plant If...

  • You have limited space, as this is a large tree.
  • You have pets that may ingest toxic plant parts.
  • You live in an area where Black Locust is considered invasive.
📍 Ideal Location: Outdoor location with full sun and well-drained soil.
🎨 Style: Naturalistic, Woodland, Rural
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Black Locust is toxic to dogs, cats, and horses. The toxic principles are robinin and lectins. Symptoms include anorexia, depression, weakness, and gastrointestinal upset (e.g., vomiting, diarrhea). All parts of the plant are considered toxic, but especially the seeds and bark.
Speedwell

Speedwell

Veronica spp.
Care: Expert Time: 15 minutes weekly (outdoor) Beginner: No

Outdoor gardeners looking for a low-maintenance, flowering groundcover or border plant that attracts pollinators.

✅ Choose This Plant If...

  • You want a low-maintenance perennial for your garden.
  • You want to attract pollinators to your yard.
  • You need a deer-resistant plant.
  • You want a long-blooming flower.
  • You want a plant with a variety of colors and growth habits.

❌ Skip This Plant If...

  • You are looking for an indoor plant.
  • You have pets that might ingest it.
  • You have limited sunlight in your garden.
📍 Ideal Location: Outdoor garden bed or border with full sun exposure.
🎨 Style: Cottage, Naturalistic, Meadow
🏠 Apartment Friendly: No
⚠️ Some species of Veronica contain glycosides that can cause mild gastrointestinal upset in dogs, cats, and horses if ingested. Symptoms may include vomiting, diarrhea, and loss of appetite. All parts of the plant are potentially 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

☀️

Locust Tree needs full sun, while Speedwell prefers full sun to partial shade.

📈

Locust Tree has fast growth, while Speedwell grows moderate to fast, some species can be aggressive spreaders.

💡 Pro Tips For Comparing These Plants

Locust Tree Care Tips

Black Locust is an outdoor tree and is not suitable for indoor cultivation. It requires full sun, well-drained soil, and is relatively low-maintenance once established. Indoor cultivation is not possible due to its size and light requirements.

  • Plant in well-drained soil to prevent root rot.
  • Protect young trees from deer browsing.
  • Prune regularly to maintain shape and remove deadwood.
  • Monitor for locust borer infestations.
  • Water deeply during dry periods, especially for young trees.
❄️ Winter: Dormant pruning can be done in late winter to remove dead or damaged branches and shape the tree. Protect young trees from harsh winter winds and frost damage.
☀️ Summer: Monitor for pests and diseases, such as locust borers and leaf miners. Water deeply during dry periods. Provide shade for young trees during extreme heat.

Speedwell Care Tips

Speedwell is primarily an outdoor plant and is challenging to grow indoors due to its high light requirements and need for specific temperature and humidity conditions. It requires full sun and well-draining soil. Indoor cultivation is not recommended.

  • Provide well-draining soil to prevent root rot.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Fertilize in spring with a balanced fertilizer.
  • Divide plants every few years to prevent overcrowding.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: In colder climates, provide mulch around the base of the plant to protect the roots from freezing. Reduce watering during dormancy. Prune back dead growth in late fall or early spring.
☀️ Summer: Water regularly during hot weather. Deadhead spent flowers to encourage continued blooming. Monitor for pests and diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Locust Tree

Common Issues: Locust borer, leaf miners, powdery mildew, root rot (in poorly drained soils)
Solutions: Locust borer: Insecticides or systemic treatments; Leaf miners: Insecticides or removal of affected leaves; Powdery mildew: Fungicides; Root rot: Improve soil drainage and avoid overwatering.

Speedwell

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

❓ Frequently Asked Questions — Comparing These Plants

Locust Tree

What are the light requirements for Locust Tree?

Locust Trees thrive in bright, indirect light. Direct sunlight can scorch the leaves, so avoid placing them in a south-facing window without some form of shading. An east- or west-facing window is ideal, providing ample light without the intensity of direct sun. If natural light is insufficient, consider using grow lights to supplement their needs. Rotate the plant regularly to ensure even growth on all sides. Insufficient light can lead to leggy growth and pale leaves. Observe your plant’s response to the light conditions and adjust its placement accordingly.

How do I care for Locust Tree?

Indoor Locust Trees require bright, indirect light and well-draining soil. Water thoroughly when the top inch of soil feels dry, allowing excess water to drain away. Avoid overwatering, which can lead to root rot. Maintain moderate humidity levels. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Prune regularly to maintain shape and remove any dead or damaged branches. Repot every 2-3 years, or when the plant becomes root-bound, into a slightly larger pot. Ensure good air circulation to prevent fungal diseases. Protect from drafts and sudden temperature changes. Monitor for pests and treat promptly if detected. Provide stable conditions for optimal growth.

How do I propagate Locust Tree?

Locust Trees can be propagated through stem cuttings or air layering. For stem cuttings, take a 4-6 inch cutting from a healthy stem. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cutting in moist, well-draining potting mix. Cover with a plastic bag to maintain humidity. For air layering, make a shallow cut on a stem and wrap it with moist sphagnum moss. Cover the moss with plastic wrap and secure it with tape. Once roots develop, cut the stem below the moss and plant it in a pot. Both methods require patience and consistent moisture.

Speedwell

What are the light requirements for Speedwell?

Speedwell flourishes in full sun, requiring at least six hours of direct sunlight each day for optimal growth and abundant blooming. While it can tolerate some partial shade, especially in hotter climates, insufficient light can lead to leggy growth and reduced flowering. When planting Speedwell, choose a location that receives ample sunlight throughout the day. If growing indoors, place the plant near a sunny window, ideally facing south or east. Rotate the plant regularly to ensure even light exposure on all sides. In areas with intense afternoon sun, providing some light shade during the hottest part of the day can prevent leaf scorch.

How do I care for Speedwell?

Speedwell thrives in well-draining soil and requires regular watering, especially during dry periods. Aim to keep the soil consistently moist, but avoid overwatering, which can lead to root rot. Provide Speedwell with at least six hours of sunlight daily for optimal blooming. In hotter climates, some afternoon shade can be beneficial. Fertilize your Speedwell every 4-6 weeks during the growing season with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers regularly to encourage continuous flowering. Prune back the plant in late fall or early spring to maintain its shape and promote bushier growth. Protect Speedwell from extreme cold and frost in colder climates. Monitor for pests and diseases, and treat promptly if necessary.

How do I propagate Speedwell?

Speedwell can be propagated through division, stem cuttings, and seeds.

Last updated: May 9, 2026 — Plant care data reviewed and verified by our editorial team.