Rue (Ruta graveolens)
Rue, also known as Herb of Grace, is a small shrubby perennial that grows 2 to 3 feet high with delicate blue-green foliage and small, bright yellow flowers. It is in the citrus family (Rutaceae) and is native to the Balkans and southeastern Europe where it is used as a bitter flavoring in traditional cuisines of the eastern Mediterranean.
Rue’s shrubby nature and charming foliage and flowers make it an excellent low-growing hedge, border, or container plant. The yellow flowers that bloom in June and July attract butterflies, but the highly fragrant leaves give off a strong aroma when crushed and can also repel insects. Planted in the garden, Rue is an effective insect-repelling companion. It is the national herb of Lithuania, and in southeastern Europe, it developed a reputation as a magical protective herb and was often planted in doorways to ward off evil spirits.
Rue is a fast-growing, low-maintenance plant. It is deer-resistant and drought-tolerant after it is established and will grow in a variety of soils as long as they are well-draining. It does best in full sun but will tolerate light shade and is hardy in USDA zones 4 to 10.
How to Grow Rue Plants
Climate and Soil Requirements
- Climate: Rue thrives in temperate climates and is best suited for USDA hardiness zones 4-9. The plant prefers warm, dry conditions and can tolerate drought and poor soil.
- Soil: Prefers well-draining, sandy or loamy soil with a slightly alkaline to neutral pH (7.0-8.0). Rue can thrive in poor soil conditions but performs best in well-amended ground.
Planting
- Location: Choose a sunny location that receives at least 6-8 hours of direct sunlight daily. Rue can tolerate partial shade but will have better foliage in full sun.
- Soil Preparation: Prepare the soil by tilling and adding sand or grit to improve drainage if necessary. Rue does not require rich soil and can thrive in relatively poor, well-drained soil.
- Planting Time: Plant seeds or young plants in the spring after the last frost. If starting from seed, sow seeds indoors 8-10 weeks before the last frost and transplant seedlings outdoors once they are sturdy.
- Spacing: Space plants 18-24 inches apart to allow adequate room for growth and air circulation.
Watering
- Establishment Phase: Water regularly to keep the soil consistently moist but not waterlogged during the first year. Consistent moisture is crucial for young plants.
- Mature Plants: Once established, Rue is drought-tolerant. Water deeply and infrequently, allowing the top inch of soil to dry out between waterings. Avoid overwatering, as Rue prefers dry conditions.
Sunlight
- Full Sun: Ensure the plants receive at least 6-8 hours of direct sunlight daily for optimal growth and robust foliage.
Fertilizing
- Minimal Fertilization: Rue thrives in poor soil and does not require heavy fertilization. Apply a light, balanced fertilizer in early spring if the soil is particularly poor.
- Frequency: Fertilize sparingly, as too much fertilizer can reduce the plant's aromatic oils and bitterness.
Pruning and Maintenance
- Routine Pruning: Prune in early spring to remove dead or damaged stems and to shape the plant. Light pruning throughout the growing season encourages bushier growth and prevents the plant from becoming leggy.
- Maintenance: Rue requires minimal maintenance once established. Mulch around the base to retain moisture and suppress weeds.
Pest and Disease Management
- Common Pests: Rue is generally pest-resistant but can occasionally attract aphids and spider mites. Use insecticidal soap or neem oil to control infestations.
- Diseases: Watch for signs of fungal diseases such as root rot and powdery mildew. Ensure proper spacing, good air circulation, and avoid overhead watering to reduce disease risk. Apply fungicides if necessary.
Harvesting Leaves
- When to Harvest: Harvest leaves as needed throughout the growing season. The best time to harvest is in the morning after the dew has dried, when the essential oils are most concentrated.
- How to Harvest: Use scissors or garden shears to cut the leaves, taking care not to damage the main stems. Harvesting regularly encourages new growth and maintains the plant's shape.
