A common use for field elm (Ulmus minor) and other types of elm trees is for their wood, which has an interlocking grain and is therefore resistant to splitting. This tree has a distinctive crown, and you can tell it apart from the similar wych elm by noting the fact that its shoots are more slender.
I. Appearance and Characteristics
Ulmus minor Mill., the field elm, is by far the most polymorphic of the European species, although its taxonomy remains a matter of contention. Its natural range is predominantly south European, extending to Asia Minor and Iran; its northern outposts are the Baltic islands of Öland and Gotland, although it may have been introduced by humans. The tree’s typical habitat is low-lying forest along the main rivers, growing in association with oak and ash, where it tolerates summer floods as well as droughts.
The tree typically grows to < 30 m (98 ft) and bears a rounded crown. The bark of the trunk is rough, furrowed lightly in older trees to form a block pattern. Young branchlets occasionally have corky wings. The shoots are slender compared with those of wych elm. The leaves are smaller than those of the other European species, hence the specific epithet minor, however they can vary greatly according to the maturity of the tree. Leaves on juvenile growth (suckers, seedlings etc.) are coarse and pubescent, whereas those on mature growth are generally smooth, though remaining highly variable in form; there are generally fewer than 12 pairs of side veins. A common characteristic is the presence of minute black glands along the leaf veins, detectable with the aid of a magnifying glass. The samarae are oval or obovate, glabrous, 12–15 mm (15⁄32–19⁄32 in) long, notched at the top, with the seed close to the notch. Ulmus minor in France generally begins to flower and fruit when aged 10 years.
The species readily produces suckers from roots and stumps, even after devastation by Dutch elm disease; consequently genetic resources are not considered endangered.
II. How to Grow and Care
Sunlight
Field elm thrives best under full sunlight, whereby the plant receives direct, unfiltered light for the majority of the day. This light intensity ensures robust growth and optimal health. It possesses a notable adaptability, tolerating partial sun, although such conditions may lead to less vigorous development and possible alterations in leaf density. The species has evolved to capitalize on high light environments, offering maximum photosynthetic efficiency. Outdoor placement should aim for locations unhindered by significant shade, harnessing field elm’s ability to absorb ample light throughout the day.
Temperature
Plants of Genus Ulmus are mainly native to the temperate zone of the northern hemisphere. These trees are known for their adaptability – they enjoy adequate sunshine, but are also tolerant to cold and drought, with a developed root system that provides resistance to strong winds and soil erosion. The trees have a long lifespan and are usually fast growers, with strong vitality.
Watering
Field elm thrives in environments that mimic its native habitat, where it experiences periodic dry spells. This species is adapted to a moderate level of drought tolerance and prefers a balance in soil moisture without being waterlogged. For optimal health, field elm should be watered once every three weeks, aligning with its ability to withstand drier conditions for extended periods. Typically grown outdoors due to its size and growth habit, field elm is an adaptable deciduous plant that responds well to the seasonal rainfall patterns in temperate climates.
Soil
Field elm can tolerate a variety of different soil types and pH values, but good drainage is a must. Fertile sandy loam is best suited to the tree’s growth, and this can be mixed with garden soil, leaf mold and river sand at a ratio of 1:1:1 as cultivation soil.
Fertilizing
For optimal growth, field elm benefits greatly from fertilization, enhancing resilience and foliage. Apply a balanced nutrition fertilizer, such as a 10-10-10 mix, in spring for overall health. During active growth, monthly applications of high nitrogen fertilizer support leaf vigor. Use specified dosages on product labels to avoid over-fertilization risks. Seasonal variations dictate reduced feeding in autumn, simulating natural cycles. Practically, incorporate fertilizer into moist soil, watering thoroughly post-application for root absorption, and ensure protective gear is worn to prevent skin or inhalation exposure.
Pruning
Prune field elm in the late winter to thin its branches and remove any that are diseased. This is also a good time to prune for tree shape. In the spring, once the branch buds sprout, you will need to remove any excessive lateral buds. Select the buds from the parts needed for cultivation to maintain the tree’s shape, as this will reduce unnecessary nutrition consumption.
Propagation
Field elm is propagated best in Autumn and Winter using hardwood cuttings, layering (air), or sowing seeds. Propagation difficulty is moderate. Signs of successful propagation include new growth and root development. Keep soil moist for optimal results.
Transplanting
The optimal time to transplant field elm is during S1-S2, typically referred to as ‘dormant season’. This is when the plant has stopped active growth, making it less stressful to uproot. Choose a location with rich, well-drained soil and sufficient sun exposure. Remember, gradual acclimatisation post-transplant is key to field elm’s successful relocation!
Pests and Diseases
The species has a hugely variable reaction to Dutch elm disease (DED), including all the fashionable pre-20th century plantsman’s clones (see Subspecies and varieties). However, field elm is genetically highly variable; Italian specimens when inoculated with the pathogen displayed between 15 and 100% dieback and between 70 and 100% wilting, whereas with trees tested in Spain, the variability ranged from 5 to 100% dieback, and 20 to 95% wilting. In 2013 researchers at the Universidad Politėcnica de Madrid announced the discovery and cloning of trees in Spain with levels of resistance greater than ‘Sapporo Autumn Gold’ (see Cultivation).
Tolerance of elm yellows (phloem necrosis) is generally good, U. minor exhibiting symptoms such as the ‘witch’s broom’ only sporadically throughout Italy, including Sicily and Sardinia, however the disease was often locally common within the species in France, including Paris.
III. Uses and Benefits
Field elm will flourish in moist but well-drained medium to large gardens where it makes an excellent shade tree. It may also be grown on boulevards as a street tree, flourishing in a range of soils. This fast-growing water lover is salt, pollution, and flood tolerant.
