Ulmus ‘San Zanobi’

Ulmus ‘San Zanobi’ (‘San Zanobi’ elm) arose from a cross of Ulmus ‘Plantijn’ and Ulmus pumila, by research scientist Lorenzo Mittempergher at the Instituto per la Protezione delle Pianti in Florence, Italy, and was released in 2003. Ulmus ‘Plinio’ comes from the same sowing. This elm was named after saint Zenobius of Florence. During a procession, his coffin touched a dead elm which spontaneously sprouted: a magnificent start of new life and a fine reference to this elm's resistance to Dutch elm disease. As a juvenile tree, the crown of Ulmus ‘San Zanobi’ is narrowly egg-shaped and in terms of growth the branching pattern is between Ulmus ‘Columella’ and Ulmus ‘Lobel’. In maturity, the branches sag which creates a semi-open, broader egg-shaped to rounded crown form - between four and eight metres wide, with good branch distribution and the same applies to the upright main trunk. ‘San Zanobi’ attains a height of twenty-five metres.

In March, ‘San Zanobi’ produces violet flowers. These are followed by stem-less, round, bright green samaras around the seeds, which fall to the ground creamy-white. The fairly large, oval and smooth leaf has the asymmetrical base characteristic of elms. The foliage emerges fresh green, turns darker green in summer and persists on the tree late in the year. The bare slender twigs and the bark are grey-green in colour, and in older trees they develop grooves in the bark.

‘San Zanobi’ is a vigorous grower which, after one or two robust rounds of pruning, obtains a good form and with its healthy appearance and ornamental silhouette make it ideal for use in the urban environment. The tree has good resistance to Dutch elm disease and its preference for drier soils in warm sites provide opportunities in a changing climate. ‘San Zanobi’ hates wet or heavy clay soils and on richer soils - because of its more vigorous growth - will likely require more pruning. This feature makes Ulmus ‘San Zanobi’ also of interest for timber production.