Maritime pine (Pinus pinaster) is a tall pine tree with habitats centered around the Mediterranean Basin, and particularly on the Iberian Peninsula. It can reach up to 35 m tall and produces cones with large wings. It roots in acidic, sandy, and even nutrient-poor soils where few commercially useful trees grow. Maritime pine is commonly harvested for timber.
I. Appearance and Characteristics
Pinus pinaster, the maritime pine or cluster pine, is a pine native to the south Atlantic Europe region and parts of the western Mediterranean.
Its range is in the western Mediterranean Basin and the southern Atlantic coast of Europe, extending from central Portugal and Northern Spain (especially in Galicia) to southern and Western France, east to western Italy, Croatia and south to northern Tunisia, Algeria and northern Morocco. It favours a Mediterranean climate, which is one that has cool, rainy winters and hot, dry summers.
It generally occurs at low to moderate altitudes, mostly from sea level to 600 m (2,000 ft), but up to 2,000 m (6,600 ft) in the south of its range in Morocco. The high degree of fragmentation in the current natural distribution is caused by two factors: the discontinuity and altitude of the mountain ranges causing isolation of even close populations, and human activity.
Pinus pinaster is a medium-size tree, reaching 20–35 metres (66–115 feet) tall with a trunk diameter of up to 1.2 m (4 ft), exceptionally 1.8 m (6 ft).
The bark is orange-red, thick, and deeply fissured at the base of the trunk, somewhat thinner in the upper crown.
The leaves (‘needles’) are in pairs, very stout (2 millimetres or 1⁄16 inch broad), up to 25 cm (10 in) long, and bluish-green to distinctly yellowish-green. The maritime pine features the longest and most robust needles of all European pine species.
The cones are conic, 10–20 cm (4–8 in) long and 4–6 cm (1+1⁄2–2+1⁄2 in) broad at the base when closed, green at first, ripening glossy red-brown when 24 months old. They open slowly over the next few years, or after being heated by a forest fire, to release the seeds, opening to 8–12 cm (3–4+1⁄2 in) broad.
The seeds are 8–10 mm (5⁄16–3⁄8 in) long, with a 20–25 mm (13⁄16–1 in) wing, and are wind-dispersed.
II. How to Grow and Care
Maritime pine is a robust, adaptable species well-suited to a range of environments. Key care needs include full sun exposure and well-drained soil, ensuring it thrives in many conditions. Special care points: irrigation is crucial during establishment, but maritime pine becomes drought tolerant as it matures. This species has a generally easy care difficulty level, requiring minimal maintenance once established.
Sunlight
Maritime pine thrives best in full sun conditions, requiring abundant, direct sunlight to optimize its growth and health. While maritime pine has a high tolerance to varying light levels, deviating significantly from direct sun exposure could negatively impact its vigor and development, potentially leading to inhibited growth or reduced resilience. An adaptation that maritime pine has developed for its ideal light conditions includes its needle-like leaves, which reduce water loss and are efficient in high-light environments. As such, maritime pine is best planted outdoors in locations where it can receive unfiltered sunlight for most of the day, ensuring its robust growth.
Temperature
The maritime pine is mostly native to the northern hemisphere and can withstand many challenging environmental conditions. Tolerant of temperatures ranging between -60 to 50 ℃, making it suitable for hardiness zones 11 and below, this is a plant that grows best in well-drained, deep and moist soil.
Watering
Maritime pine thrives in its native habitat with a natural preference for well-drained soils and periodic dry spells, indicating moderate drought tolerance. Its watering needs are best met with a schedule of once every 1-2 weeks, ensuring the soil has time to dry between waterings. Typically grown outdoors due to its size and growth habit, maritime pine is an evergreen plant that requires careful consideration of soil moisture levels to prevent root rot while maintaining needle health.
Soil
Maritime pine can grow in a variety of different soil types, including bare mineral soil, sandy soil, volcanic ash, calcareous soil, limestone soil, and everything from dusty soil to red soil. Since it is resistant to drought, it will even grow in barren landscapes. However, it grows best in loose, fertile, well-drained, and slightly acidic soil. In the case of too much alkalinity, needles of potted plants will turn yellow and fall, so it is best to use natural mountain soil in pots and containers.
Fertilizing
For maritime pine, use balanced nutrition fertilizers to enhance growth and vigor. Apply in early spring and mid-fall, sparingly, to avoid runoff. Granular, slow-release formulas tailored to conifers are ideal. With different seasons, adjust quantity; less in dormant winter, more in active growth phases. Precautions include avoiding overfertilization and keeping away from the trunk base. Practical tip: water maritime pine after fertilizing for optimal nutrient absorption.
Planting Instructions
Maritime pine is best planted in early spring. Ideally, use healthy and vigorous seedlings with soil balls, as this can greatly improve the survival rate. In the case of many lateral roots, the deep main root can be cut. Otherwise, the root system should be protected to avoid damage.
Plant in a high, dry, well-drained, and well-ventilated place, with loose soil. In low-lying places with accumulated water, or places with sticky soil, try building a platform or changing the soil before planting. The planting pit should be treated with a basal fertilizer before planting. Newly planted large seedlings should be supported to prevent them being blown down by the wind. Before planting, excess branches should be pruned off. Protect the plant’s shape from damage as much as possible, as this will help to restore growth at a later stage.
Ideally, plant indoor potted plants in the spring, and repot every two or three years in the late fall or early spring. Repotting too frequently will lead to the death of the plant. If the plant is growing weakly, find out the cause of this and change the flowerpot soil, or replant in a larger pot.
Cut back on water before repotting, so as to keep the soil slightly dry. Remove the soil ball from the pot, keeping it whole, and then prune away any old roots from the bottom and sides. Remove some of the old soil from the middle of the soil ball, replace with new soil, apply a small amount of basal fertilizer, and then cover the plant with new soil. Ensure a suitable pot size – a deep pot will easily accumulate water, leading to root rot.
Pruning
For an indoor potted plant, any dead, diseased or damaged branches should be removed. You can then adjust the tree’s shape by pruning branches, pinching buds, and trimming leaves, giving you a better ornamental effect. Prune the plant before all of its needles fall off, so as to obtain a compact shape, richer lateral and side branches, and a better form overall. Pruning should be done during the dormancy period, so as to prevent excess loss of sap and damage to the plant’s vigor.
For a plant in a garden, dense lateral branches should be pruned so as to improve the survival rate. Remove excess lateral branches during the vigorous growth period based on needs, focusing on encouraging the trunk to grow tall and straight. Cut off any diseased or dead branches right away, so as to prevent the spread of pathogens.
Propagation
Maritime pine, a coniferous tree native to the Mediterranean region, is best propagated through sowing. Propagation starts with the collection of cones, from which seeds are extracted. The seeds require pre-sowing treatments, such as stratification to overcome dormancy. It is essential to maintain optimal moisture and temperature conditions post-sowing to ensure successful germination and growth.
Practical guidance suggests using well-draining soil and providing consistent care during the early stages of development for healthy seedlings. Careful attention must be given to protect young plants from pests and diseases.
Transplanting
For maritime pine, ushering them into a new location thrives best as warmth returns and frost bids farewell—typically late spring. Choose a sunny site with well-draining soil to allow maritime pine to establish robust roots.
III. Uses and Benefits
Pinus pinaster is widely planted for timber in its native area, being one of the most important trees in forestry in France, Spain and Portugal. Landes forest in southwest France is the largest man-made maritime pine forest in Europe. It has also been cultivated in Australia as a plantation tree, to provide softwood timber. P. pinaster resin is a useful source of turpentine and rosin.
In addition to industrial uses, maritime pine is also a popular ornamental tree, often planted in parks and gardens in areas with warm temperate climates. It has become naturalized in parts of southern England, Uruguay, Argentina, South Africa and Australia.
It is also used as a source of flavonoids, catechins, proanthocyanidins, and phenolic acids. A dietary supplement derived from extracts from P. pinaster bark called Pycnogenol is marketed with claims it can treat many conditions; however, according to a 2012 Cochrane review, the evidence is insufficient to support its use for the treatment of any chronic disorder.