Weymouth Pine

Family Pinaceae (Pínus). Name: strobus - an original Linnaean taxon (apparently has the same root as the term strobile – the reproductive organ of conifers, i.e. the cone)

Pinus strobus – translated from Latin as “pine with cones”. For practical usage the Russian taxon was named Weymouth pine. In 1705 Lord Weymouth introduced this pine from America and planted it on his estate. In nature it grows in the eastern part of North America, the southeastern provinces of Canada, and also on the French islands of Miquelon and Saint-Pierre.

It is a graceful ornamental tree 40-50 m tall, 100-180 cm wide and 10-15 m in diameter. Crown dense, broadly branched, narrowly pyramidal when young and with horizontally spreading branches in maturity. Buds ovoid-cylindrical in shape, light brown, 0.4-0.5 cm long, slightly resinous.

Bark light gray when young, becoming darker and rougher with age, developing deep fissures and irregular large plates with a faint purple tint.

Foliation and branching are sparse. The trunk in youth is glossy, smooth, gray-green, in old trees – plated, deeply furrowed. Young shoots are thin, pubescent or glabrous, brownish-green, under the leaf cushions.

Needles in bundles of 5, thin, soft, 6-10 cm long and 0.7-1 mm wide, bluish-green, directed sideways or upwards, straight or slightly curved, flexible. Needle margins finely serrate, tips sharp. Retained on the tree for 2-3 years.

Blooms in April-May. Male cones are elliptical, light brown, 0.4-0.5 cm long, slightly resinous. Female cones before opening are cylindrical or narrowly cylindrical, after opening become ovoid-cylindrical, ripen every two years in late September, shed seeds and then fall. Cone length 8-20 cm, symmetrical, brownish or pale brown, with a gray or purple tint. Grow in clusters on stalks 2-3 cm long. Seeds oval or ovoid, laterally compressed and tapered at both ends, 5-6 mm long, reddish-brown with dark mottling. Wing 1.8-2.5 cm long, pale brown, easily separates from the seed.

Hardiness zone 5a. Shade-tolerant, less demanding of light than Scots pine and black pine. Resistant to heavy snow loads and strong wind, more tolerant of smoke and gas than Scots pine. Fast-growing, especially during the 10-40 year period. By 40 years reaches a height of 18-19 m. Lives more than 400 years.

Forms: has numerous ornamental forms: pyramidal (f. fastigiata), weeping (f. pendula), dwarf (f. nana), umbrella-shaped (f. umbraculifera), prostrate (f. prostrata), golden (f. aurea), silvery (f. nivea), bluish (f. glauca), variegated (f. variegata). Cultivars: Macopin ("Macopin"), "Pumila" Dwarf ("Ritila"), "Radiata" Radiant ("Rediata").

Location: prefers sunny, open sites. Can grow on almost any soil type except saline soils. Develops best on moist neutral or leached (with lime added) chernozems, sandy loams or loams with good drainage. It is not recommended to plant near gooseberry, currant, rowan, or hawthorn. Poorly tolerates continental conditions. Prefers well-drained soil and a cool, moist climate.

Planting: planting is recommended from late August to mid-October or in late April to early May. For group planting, spacing between seedlings is kept at about 1.5 m for small forms and 4 m for large forms. The planting hole depth 0.7-0.9 m. It is recommended to make a 15-20 cm drainage layer of broken brick at the bottom. Garden soil should be amended with sand; for acidic soils add lime at 200-300 g, for fertilizing the plant use nitroammophoska (50 g). The root collar should be at soil level. After planting, water the soil abundantly.

Care: young trees require regular abundant watering; mature pines are drought-tolerant. In autumn it is recommended to perform water-charging irrigation 3-4 times with 10-15 liters per plant. Mulching is necessary to retain soil moisture. If the soil around the trunk becomes compacted, loosen it, mixing the mulch layer with the soil, and in autumn reapply mulch.

Pruning: formative and sanitary pruning are recommended. Formation of a dense crown is produced by pinching the annual shoot growth.

Pests: pine aphids, adelgids, coniferous mealybugs, pine scale, pine bark bug, spider mite, red pine sawfly, pine tussock moth, pine shoot moth, pine geometrid moth, pine owlet moth, pine mining moth, cone moth, cone pyralid, pine bark beetle, large and small pine weevils, pine longhorn beetle, pine jewel beetle, pine elephant weevil, dotted pyralid.

Diseases: rust fungi, scleroderris (umbrella disease), Schütte, bark necrosis, spring sunscald.

Propagation: propagated by seeds sown outdoors in early spring. Seeds should be pre-stratified for a month. Highly ornamental forms are also propagated by grafting.

Uses: used in shelterbelts, for planting forest edges, slopes, retaining walls, Japanese gardens, heaths, rock gardens and alpine beds. Combines well with tsuga, pseudotsuga, linden, beech, oaks, hazel, sea buckthorn, Elaeagnus, maples, larch, spruce and fir.