Sakhalin Daisy
reynoutria sachalinensis
Also known as: ["Sakhalin Fleeceflower","Giant Japanese Knotweed"]
Overview
A large, herbaceous perennial plant native to Sakhalin Island and other parts of East Asia, known for its rapid growth and tall, hollow stems.
Benefits & Perks
["fast growing","wildlife attractant (bees, butterflies, birds)","drought tolerant","rare/collector’s item"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Caryophyllales |
| Family: | Polygonaceae |
| Genus: | Reynoutria |
| Botanical Name: | Reynoutria sachalinensis |
Plant Characteristics
Basic Information
- Category: Herbs & Weeds
- Suitable Location: garden bed or border in temperate regions
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"–34–38°C"}
- Hardiness: {"zones":"3–9"}
- Misting: rarely required
- Drainage: Moderately well-draining. Avoid waterlogged conditions.
- Soil Type: Rich, loamy soil with good organic matter. Tolerates a range of soils but prefers fertile conditions.
Maintenance Level
- Maintenance Level: very low
- Toughness Level: very high
- Pruning Frequency: Annually in late winter or early spring before new growth begins.
- Pruning Intensity: Moderate to heavy, depending on desired size and shape.
Care Details
Ideal Sunlight Coverage:
Full sun to partial shade (4–6 hours of direct sunlight daily). Tolerates light shade but may become leggy.
Sunlight Tolerance Tips:
Acclimate new plants gradually to direct sun to prevent scorching. In hot climates, provide afternoon shade. Indoors, place near a south-facing window with filtered light.
Care Requirements
Care Difficulty
easymoderate
Sunlight
full sun to partial shade
Rotate plant for even growth; use sheer curtains to diffuse intense light; monitor for sunburn.
Watering
every 7–10 days during active growth, reduce in winter
Water thoroughly until runoff, allow soil to dry partially between waterings, and avoid waterlogging.
Soil
rich, moist, well-drained loam
pH: Slightly acidic to neutral (pH 6.0–7.0).
Mulch to retain moisture; avoid compacted soil; test pH annually.
Temperature
Hardy in USDA zones 3–9. Prefers 60–75°F (15–24°C) during growth; tolerates winter lows to -30°F (-34°C).
Protect from late spring frosts; ensure good air circulation in heat; avoid sudden temperature swings.
Fertilizing
every 4–6 weeks during growing season
Avoid over-fertilizing to prevent excessive growth; use organic matter as a slow-release supplement; test soil before fertilizing.
Propagation
Methods
Stem cuttings or division. Stem cuttings root readily in warm conditions.
Step-by-Step Propagation Guide
- Take 4–6 inch cuttings.
- Remove lower leaves.
- Dip in hormone (optional).
- Plant in medium.
- Maintain moisture and warmth.
Best Time: Late spring to early summer when the plant is actively growing.
Environment
High humidity (70–80%), warm temperatures (65–75°F), and indirect light.
Medium
Well-draining potting mix with perlite or sand. Can also root in water initially.
Hormone
Rooting hormone is optional but recommended for faster rooting.
Timeline
Roots develop in 3–4 weeks; new growth appears in 6–8 weeks.
Tools Needed
Pruners, rooting hormone, pots, well-draining medium, misting spray bottle.
Quick Tips
Use sharp, sterile tools; keep cuttings out of direct sun; maintain consistent moisture.
Pruning & Repotting
Pruning Guide
Method
Cut stems back to a healthy bud or lateral branch. Remove crossing or crowded stems.
Pruning Plan
Prune to control size, remove dead/damaged stems, and encourage bushier growth.
Tools
Pruning shears, loppers (for thicker stems), gloves.
Checklist
Sterilize tools; cut at a 45-degree angle; remove dead/diseased wood; clean up debris.
Repotting Guide
Best Season
Early spring before active growth starts.
Pot Size
Increase pot size by 2–3 inches in diameter.
Method
Remove plant gently; trim roots if crowded; place in a new pot with fresh soil; water thoroughly.
Suggestions
Repot every 2–3 years or when roots fill the container. Necessary to refresh soil and provide space.
Checklist
Choose new pot; prepare fresh soil; inspect roots; water after repotting; place in shade temporarily.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture with finger; water deeply; ensure drainage; adjust seasonally.
How to Apply Water Properly
Water directly at the root zone, ensuring even saturation to a depth of 6–8 inches. Ensure excess water drains freely to prevent root rot. Water early in the morning to minimize evaporation.
Watering Schedule Tips
Water deeply once per week during active growth, reducing frequency to every 2–3 weeks in winter. Adjust based on rainfall and soil moisture retention.
Soil Improvement
Add compost or well-rotted manure to enhance fertility and structure. Incorporate perlite or sand for drainage if needed.
Temperature Stress Management
Signs of Temperature Issues
Chlorosis or leaf scorch in excessive heat; stunted growth or dieback in prolonged cold without protection.
Cold Stress
Leaves may wilt or turn yellow; growth slows or halts. Roots can freeze in poorly drained soil.
Solution: Mulch heavily around the base in fall; avoid overwatering before freezes; use frost cloth in marginal zones.
Hot Stress
Wilting, leaf drop, or scorched foliage due to excessive transpiration.
Solution: Provide shade during peak heat; increase watering frequency; use mulch to retain soil moisture.
Fertilizing Guide
Fertilizing Checklist
Check soil pH; follow label dilution; fertilize in spring/summer; avoid winter feeding.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring. Apply a diluted liquid fertilizer monthly during growing season, ceasing in fall.
Common Problems & Solutions
Toxicity Warning
Cats
Non-toxicReynoutria sachalinensis is not considered toxic to cats. The plant does not contain known toxic substances that would harm feline health.
⚡ Toxic If:
Generally non-toxic
Dogs
Non-toxicReynoutria sachalinensis is not considered toxic to dogs. There are no known toxic compounds in this plant that would pose a risk to canine health.
⚡ Toxic If:
Generally non-toxic
Humans
Non-toxicReynoutria sachalinensis is not considered toxic to humans under normal circumstances. It lacks significant toxic compounds that would cause adverse physiological effects.
⚡ Toxic If:
Generally non-toxic
Frequently Asked Questions
Q: Is Reynoutria sachalinensis invasive?
A: Yes, it is considered highly invasive in many regions due to its rapid growth and ability to outcompete native species.
Q: Does this plant have any medicinal uses?
A: Traditional uses are limited, but related species in the Polygonaceae family have been studied for potential health benefits.
Q: How should I control its spread?
A: Regularly monitor and remove new shoots, and consider using physical barriers or herbicides in severe cases.
Quick Reference
| Family: | Polygonaceae |
| Care: | easy |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during activ |
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