Ulmus laevis Seeds | European White Elm
LATIN NAME: Ulmus laevis
COMMON NAME: European White Elm
Plant Profile
European white elm is the riverbank elm of central and eastern Europe, a tall tree of twenty-five to thirty-five metres with a broad, open crown and a trunk that widens into buttresses at the base. Its leaves are large, asymmetrical and softly hairy beneath, and its flowers hang on long, slender stalks, a detail that separates it from the other European elms at a glance. It grows on floodplains and along slow rivers, where its roots reach the water table, and it tolerates weeks of standing water better than any of its relatives. The wood is lighter and softer than that of field elm, and less valued. Unlike the other elms it has largely escaped Dutch elm disease, which has made it a species of renewed interest.
Science & Biotechnology
The resistance of Ulmus laevis to Dutch elm disease is not absolute but it is substantial, and the reasons are still being worked out. The bark beetle vectors prefer the thicker bark of other elms, and the species flushes later, which may desynchronise it from the beetle’s breeding cycle. Its xylem anatomy, with wider vessels and a different pit structure, may also slow the spread of the fungus. Whatever the mechanism, surveys after the European epidemic found mature white elms surviving in riverine woods where field elm had gone. The species is now a priority for conservation and for breeding, and its genetic diversity is higher than that of the other European elms, probably because floodplain populations stayed connected along rivers. It is also susceptible to elm yellows, a phytoplasma disease spread by leafhoppers.
Uses & Benefits
The timber is used for furniture, for packing cases and for light construction, and it works easily but rots quickly when wet, so it is not a wood for outdoor use. The tree is planted for floodplain restoration, for windbreaks and as a shade tree in wet ground where other trees fail. Its roots stabilise riverbanks, and its canopy shades the water, which benefits fish. In the garden it suits a large, damp site or the edge of a pond, where its buttressed base and open crown look well. It is fast-growing when young and can put on a metre a year. The samaras feed birds in late spring, and the tree supports a range of moth larvae, including the white-letter hairstreak.
Growing from Seed
Collect the samaras in late May or June, when they turn papery and pale, and sow them immediately. They lose viability within a few weeks, so do not store them. Surface-sow in a tray of loam, sand and leaf mould, cover with grit, and keep standing in shallow water, since this species germinates in damp conditions. Germination takes one to three weeks. Prick out into deep pots and grow on in full sun with ample water. Plant out in autumn into moist or periodically flooded ground, and stake for two years. The tree transplants well when young, unlike most elms, and it grows fast enough to make a specimen within fifteen years.
Our Take
The elm that survived the epidemic, and the one for a wet corner. Fast, tolerant and far less likely to die.
Related Reading
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