Populus alba aka Silver Poplar

White poplar is extremely cold hardy, tolerating temperatures well below -20°C (-4°F) in USDA zones 3-9. It thrives in regions with cold to mild winters and hot summers, making it adaptable to a wide temperature range. Once established, the tree handles both winter freezes and summer heat without issues.

White poplar is not particularly demanding regarding humidity levels and adapts to various atmospheric conditions. Native to regions ranging from Mediterranean climates to continental areas, it tolerates both humid and drier air conditions. The tree's main moisture requirement is soil water rather than atmospheric humidity.

White poplar is deciduous and goes dormant in winter after leaf drop. In early spring, it produces catkins before leaves emerge. The main growing season is spring through summer when it exhibits fast growth. Water needs are highest during the growing season, though established trees are quite drought tolerant. Minimal seasonal care is needed beyond ensuring adequate moisture during establishment.

White poplar is dioecious, producing separate male and female catkins on different trees in early spring. Male catkins are grey with dark red stamens, while female catkins are greyish-green. After wind pollination, female catkins lengthen to 8-10 cm and develop seed capsules that mature from late spring to early summer, releasing cottony seeds.

Notable cultivars include 'Richardii' (Golden Leaved Poplar) with greenish-yellow leaves and white-felted undersides growing to about 12m, 'Pyramidalis' (syn. 'Bolleana') a slender pyramidal form from Turkestan resembling Lombardy poplar but wider, and 'Nivea' a variety published in 1789. 'Richardii' is particularly popular for its striking golden-and-white foliage that flutters in the breeze.

White poplar is exclusively an outdoor tree, hardy in USDA zones 3-9 and UK zone 3. It requires full sun and ample space, as mature trees reach 50-75 feet tall and wide. The tree is commonly planted in parks, along roadsides, and in coastal areas for dune stabilization. However, its aggressive root suckering habit makes it unsuitable for small gardens or near buildings and paving.

White poplar requires minimal pruning beyond removing dead, damaged, or crossing branches in late winter while dormant. The main maintenance challenge is managing vigorous root suckers that can appear up to 50 meters from the parent tree. These suckers should be removed promptly by cutting or mowing to prevent unwanted colony formation. Avoid heavy pruning as it can stimulate excessive suckering.

White poplar propagates easily through hardwood cuttings in winter, root suckers in autumn or late winter, or seeds. Seeds require no stratification and germinate rapidly when mature, though they germinate better when not covered with soil. The tree naturally spreads via root suckers that can extend up to 50 meters from the parent plant, forming extensive clonal colonies.

White poplar is susceptible to numerous pests and diseases including borers (major problem), aphids, leaf beetles, sawflies, and caterpillars. Disease issues include dieback, cankers, leaf spot, powdery mildew, and rust. University extensions note that a very wide range of pests and diseases tend to kill these trees off, making white poplar relatively short-lived despite fast growth.

White poplar is wind-pollinated and dioecious, meaning individual trees are either male or female. Male trees produce grey catkins with dark red stamens that release pollen in early spring, while female trees have greyish-green catkins that capture airborne pollen. Interestingly, in cultivation in northern Europe, the majority of white poplars are female trees.

White poplar has very limited edibility. The leaves are rich in Vitamin C and can be eaten, while the inner bark can be dried, ground into powder, and added to flour for bread-making. However, PFAF describes the bark as a famine food that is only used when all else fails, indicating poor palatability and nutrition compared to conventional food sources.

The stem bark contains salicin (the compound used to make aspirin) and is used as an anti-inflammatory, pain reliever, and fever reducer. Internally, it treats rheumatism, arthritis, gout, back pain, urinary complaints, digestive disorders, and menstrual cramps. Externally, the bark treats chilblains, hemorrhoids, infected wounds, and sprains. The leaves are used for dental and bone conditions, while twigs have detoxifying properties.

White poplar wood is lightweight, resistant to abrasion, and low flammability, used for various timber applications. The bark yields a yellow dye. An extract from shoots serves as a natural rooting hormone for plant cuttings. The tree is planted for shelterbelt windbreaks, erosion control, and coastal sand dune stabilization due to its extensive root system, fast growth, and salt tolerance.