Creeper elm
ulmus thomasii
Also known as: ["Thomas' elm","creeper elm"]
Overview
A deciduous tree native to North America, known for its distinctive bark and ecological significance.
Benefits & Perks
["wildlife attractant (bees, butterflies, birds)","shade tolerant"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Urticales |
| Family: | Ulmaceae |
| Genus: | Ulmus |
| Botanical Name: | Ulmus thomasii |
Plant Characteristics
Basic Information
- Category: Trees
- Suitable Location: outdoor planting in open woodland or park setting
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"-30–40°C"}
- Hardiness: {"zones":"3–5"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Moderate to fast-draining soil.
- Soil Type: Well-draining, loamy soil with organic matter. Tolerates a range of soil types but prefers fertile conditions.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: moderate
- Pruning Frequency: Annually in late winter or early spring before new growth begins.
- Pruning Intensity: Moderate pruning to remove deadwood and shape the tree; avoid heavy pruning unless necessary.
Care Details
Ideal Sunlight Coverage:
Full sun to partial shade (4–6 hours of direct sunlight daily). Adjust for seasonal changes, providing more shade during peak summer.
Sunlight Tolerance Tips:
Acclimate the tree gradually to full sun if moved from shade. Protect from intense midday sun to prevent scorching. Outdoor placement is ideal, but ensure partial shade in hot climates.
Care Requirements
Care Difficulty
moderatemoderate
Sunlight
full sun to partial shade
Monitor for leaf scorch; provide afternoon shade in summer; rotate the tree for even light exposure.
Watering
every 7–10 days during growing season, reduce in winter
Water thoroughly but infrequently to encourage deep root growth; avoid overwatering to prevent root rot; water early in the day to minimize evaporation.
Soil
deep, fertile, well-drained loam
pH: Slightly acidic to neutral (pH 6.0–7.0).
Ensure good drainage; amend with organic matter; test soil pH periodically.
Temperature
Hardy in USDA zones 4–8, tolerating temperatures from -30°F to 90°F. Prefers cooler temperatures during dormancy.
Protect from late frosts; water deeply before cold snaps; avoid pruning in extreme temperatures.
Fertilizing
every 3–4 months with balanced slow-release fertilizer
Fertilize only in spring; avoid nitrogen-heavy fertilizers; water well after application.
Propagation
Methods
Seed propagation is most common. Softwood cuttings can also be used but are less reliable.
Step-by-Step Propagation Guide
- Collect seeds in fall.
- Stratify seeds for 60–90 days.
- Sow in spring.
- Keep moist and warm until germination.
Best Time: Spring for seeds; early summer for cuttings when new growth is soft but firm.
Environment
Warm, humid environment with indirect light for cuttings. Cool stratification may be needed for seeds.
Medium
Well-draining seed starting mix or a mix of peat and perlite for cuttings.
Hormone
Rooting hormone is optional for seeds but recommended for cuttings to improve success rates.
Timeline
Seeds may take 1–3 months to germinate. Cuttings may root in 4–8 weeks.
Tools Needed
Pruners, rooting hormone, seed trays, misting bottle, heating mat (optional).
Quick Tips
Use fresh seeds for best germination; maintain consistent moisture; protect cuttings from direct sun.
Pruning & Repotting
Pruning Guide
Method
Use clean cuts just above a bud or branch collar. Remove crossing or rubbing branches.
Pruning Plan
Prune to maintain shape, remove dead or diseased wood, and improve air circulation.
Tools
Hand pruners, loppers, pruning saw, disinfectant.
Checklist
Disinfect tools; prune dead or diseased wood first; make clean cuts; avoid topping the tree.
Repotting Guide
Best Season
Early spring before active growth begins.
Pot Size
Increase pot size by 2–3 inches in diameter for container-grown saplings.
Method
Remove the plant gently, trim roots if necessary, place in a larger pot with fresh soil, and water thoroughly.
Suggestions
Not typically repotted as it is a large tree. Container-grown saplings should be repotted every 2–3 years.
Checklist
Choose the right pot size; use fresh soil mix; trim roots if pot-bound; water well after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply; ensure drainage; avoid wetting foliage.
How to Apply Water Properly
Water at the base of the tree, ensuring moisture reaches the root zone. Apply water slowly to allow absorption and avoid runoff. Ensure proper drainage to prevent waterlogging.
Watering Schedule Tips
Water deeply once a week during the growing season, reducing frequency in winter. Adjust based on rainfall and soil moisture levels.
Soil Improvement
Add compost or well-rotted manure to improve fertility and structure. Incorporate sand or perlite for better drainage if needed.
Temperature Stress Management
Signs of Temperature Issues
Leaf scorch, wilting, premature leaf drop, or stunted growth in extreme heat or cold.
Cold Stress
Low temperatures can cause dieback, reduced vigor, or delayed bud break in spring.
Solution: Plant in a sheltered location; apply mulch to insulate roots; avoid late-season fertilization to prevent frost damage.
Hot Stress
Excessive heat can lead to leaf scorch, wilting, and reduced photosynthesis.
Solution: Provide shade during peak heat; increase watering frequency; use mulch to retain soil moisture.
Fertilizing Guide
Fertilizing Checklist
Check soil nutrient levels; apply fertilizer in spring; water thoroughly after fertilizing.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring. Apply according to package instructions, avoiding over-fertilization.
Common Problems & Solutions
Toxicity Warning
Cats
Non-toxicUlmus thomasii is not toxic to cats. The plant does not contain any known substances that are harmful to felines when ingested.
⚡ Toxic If:
if eaten
Dogs
Non-toxicUlmus thomasii is not toxic to dogs. The plant does not contain any known substances that are harmful to canines when ingested.
⚡ Toxic If:
if eaten
Humans
Non-toxicUlmus thomasii, commonly known as the corkbark elm, is not considered toxic to humans. There are no known toxic compounds or physiological effects associated with the consumption of any part of this plant.
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Is Ulmus thomasii suitable for urban planting?
A: Yes, but it is susceptible to Dutch elm disease, which may limit its longevity in urban environments.
Q: Does Ulmus thomasii produce edible fruits?
A: The seeds are technically edible but not commonly consumed by humans.
Q: How does Ulmus thomasii differ from other elms?
A: It is distinguished by its deeply furrowed, cork-like bark and its preference for rich, moist soils.
Quick Reference
| Family: | Ulmaceae |
| Care: | moderate |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during growi |
Get Expert Care Tips
Download the Plantious app for personalized care reminders and plant identification!
Google Play App Store
