Hippophae rhamnoides (Sea Buckthorn)

Description

Hippophae rhamnoides, commonly known as sea buckthorn, is a deciduous shrub or small tree native to Europe and Asia. It typically grows 2–6 metres tall and is well-known for its bright orange berries and silvery-green, narrow leaves. The plant is dioecious, meaning male and female flowers grow on separate plants, and both are required for fruit production.

It is highly resilient, tolerating a wide range of soils and conditions, including sandy, saline, and nutrient-poor environments. Sea buckthorn has a deep and spreading root system that helps prevent soil erosion and improves soil fertility through nitrogen fixation.

Propagation

1. From Seed:

   • Collect ripe berries (spring in the Southern Hemisphere, typically September–November).
   • Extract seeds by mashing berries and rinsing the pulp away.
   • Stratify seeds by storing them in damp sand in the fridge (2–5°C) for 1–3 months before sowing.
   • Sow seeds in spring (September–November) in trays filled with a well-draining seed mix.
   • Keep soil consistently moist until germination, which takes 2–3 weeks.

2. From Cuttings:

   • Take hardwood cuttings during winter (June–August).
   • Select healthy, 20–25 cm long stems from the previous season's growth.
   • Remove lower leaves and dip the cut end in rooting hormone.
   • Plant cuttings in a sandy soil mix and keep them moist until roots develop (usually within 2–3 months).

3. From Root Suckers:

   • Sea buckthorn naturally produces suckers from its roots. These can be dug up in late winter or early spring and transplanted to a new location.

Cultivation

• Climate: Prefers cool to temperate climates. It is hardy to frost and tolerates temperatures as low as -40°C.
• Sunlight: Requires full sun for optimal growth and fruit production.
• Soil: Thrives in well-drained, sandy, or loamy soils with a pH of 6–7.5. Avoid waterlogged conditions.
• Watering: While drought-tolerant once established, young plants require regular watering until their roots are established.
• Fertilisation: Minimal fertilisation is needed due to its nitrogen-fixing ability, but a light application of compost or a balanced fertiliser in spring can support growth.
• Pruning: Prune in late winter to remove deadwood and shape the plant.
• Pests and Diseases: Generally pest-free, though occasional aphids or fungal issues may arise in humid conditions.

Uses and Benefits

1. Nutritional:

   • The berries are rich in vitamins C, A, E, and K, antioxidants, omega fatty acids, and flavonoids.
   • Often used in juices, jams, teas, and oils.

2. Medicinal:

   • Used to boost immunity, promote skin health, and reduce inflammation.
   • Sea buckthorn oil is used topically for skin conditions and wound healing.

3. Ecological:

   • Acts as a pioneer species in degraded or eroded areas, improving soil fertility through nitrogen fixation.
   • Provides habitat and food for wildlife, including pollinators and birds.

4. Other Uses:

   • Its wood can be used for small crafts, and the plant serves as an effective windbreak or hedge in agroforestry systems.

Integration into a Forest Garden

Sea buckthorn is an excellent addition to a forest garden due to its multifunctionality:

• Nitrogen Fixation: Enhances soil fertility, benefiting nearby plants.
• Windbreak: Can be planted on the forest garden's edge to protect other species from strong winds.
• Biodiversity: Attracts pollinators with its flowers and birds with its berries.
• Edible Yield: Provides a high-value fruit crop with numerous culinary and medicinal uses.
• Layering: Fits well in the shrub layer of a forest garden, with smaller companion plants thriving beneath its canopy.