Ulmus glabra Seeds | Wych Elm
LATIN NAME: Ulmus glabra
COMMON NAME: Wych Elm
Plant Profile
Pick up a winged fruit from a wych elm and the seed sits dead centre in the middle of the disc, like a stone in the middle of a coin. Pick one from a field elm and the seed is pushed over to one side, almost touching the edge. It is the quickest identification in the genus. The samara spins as it falls, which keeps it in the air and buys distance from the parent tree.
The leaves give the second clue: wych elm carries the largest leaf in the genus, broad and rough above with a strongly unequal base and a long drawn-out tip, on distinctly hairy twigs and buds. Field elm is smaller-leaved, smoother-budded and, crucially, builds thickets of root suckers where wych elm does not. On narrow-leaved and smooth-leaved elms the seed also sits near the wing margin.
The disease that emptied the elm out of the European landscape is caused by ascomycete fungi, chiefly Ophiostoma ulmi and the far more aggressive Ophiostoma novo-ulmi. Both are carried by elm bark beetles, above all the larger elm bark beetle Scolytus scolytus and the smaller European elm bark beetle Scolytus multistriatus, which breed in the bark of dying elm and feed in the crotches of healthy twigs.
In cool, wet, windy country the beetle vectors work less effectively, and wych elm there often flowers and sets fertile seed before the crown is lost. Even a badly affected tree can survive as a bushy stump that pushes new growth and flowers young, which is exactly what makes seed. In the west of Scotland and in Ireland this has left a small tree of banks and shelter belts.
Science & Biotechnology
Elm breeding has continued since the first epidemic, notably in the Netherlands, where crossings within Ulmus × hollandica produced the ‘Commelin’ group of selected clones, and later in programmes that screened Asian species for tolerance. Laboratories have used micropropagation and somatic embryogenesis to bulk up selected genotypes quickly, and molecular markers to tell clones apart and check parentage.
The inner bark of wych elm is tough, stringy and mucilaginous, and it was put to a different use from the timber: cut into strips and soaked, it served as rope and as coarse lashing, and in country practice the mucilaginous inner layer went on as a soft poultice. Similar inner bark from the North American elms became the slippery elm of the herbal trade.
Uses & Benefits
Most European elms regenerate aggressively from their roots, and a hedgerow of field elm is often one organism. Wych elm does not behave that way. It spreads almost entirely by seed, which is why it so often stands as a single broad tree in a hedge or on a rocky bank rather than as a thicket, and why northern populations depend so heavily on a good seed crop.
The habit has consequences in the nursery and in the landscape. A tree that does not sucker cannot be relied on to regenerate a cut hedge, but it also cannot spread root-borne disease between adjacent properties. Named garden forms, including the weeping clones that are layered and grafted, keep their character precisely because the plant does not throw suckers from the stock.
Elm wood resists splitting when it is worked, which made it the traditional timber for chair seats, for the curved boards of cartwheel hubs and for coffins, and it was used for the parts of boats and piers that stayed wet. Wych elm timber is heavy and hard on hand tools but takes a good finish. As an ornamental it is valuable on exposed, wet sites.
Growing from Seed
Inside the tree the fungus grows through the water-conducting vessels of the outer wood. The tree plugs those vessels with tyloses and gum, and it is this sealing rather than the fungus itself that kills the crown: water cannot reach the leaves, so the foliage flags and browns on one side before the whole crown dries. A browning branch that bends into a shepherd’s crook is the classic symptom.
Elm samaras lose their power of growth quickly once dry, so sow them as soon as they are ripe, while the wing is still soft. Scatter them over a seedbed of loam and leaf mould with the wing barely covered, keep the bed shaded and watered, and thin the seedlings once the second pair of true leaves has opened so the young trees stand a hand apart. Lift them for lining out in the first dormant season.
Our Take
Wych elm is worth planting again for its own sake, not as a substitute for the avenues that were lost, and fresh samaras sown in a shaded bed will give you sturdy young trees. Our pages on the field elm and on slippery elm cover the two elms most often confused with it, and the European white elm is the choice for riverside ground.
Related Reading
Readers interested in Wych Elm frequently explore these as well: