Alnus jorullensis is one of the fastest shade trees available, adding up to 1.2 metres a year on a straight clean trunk. The Mexican Alder holds its foliage through most of the year in mild districts, behaving as a semi-evergreen rather than a true deciduous tree.
Alnus jorullensis grows to 15 to 20 metres tall and 10 to 15 metres wide, forming an upright pyramidal canopy that broadens with age. That combination of speed and clean form makes it a common specification for quick avenue planting, screening and civic shade where results are needed within a few years.
This tree is frost hardy, surviving heavy and frequent frost without damage, and grows in full sun to part shade. It tolerates a wide range of soils including wet ground, and like other alders it fixes nitrogen, which improves the soil as it grows.
Frequently Asked Questions
About Alnus jorullensis
How fast does Alnus jorullensis grow?
Very fast, at 70 centimetres to 1.2 metres per year. It is among the quickest shade trees available and delivers useful canopy within three to four years.
Is the Mexican Alder evergreen or deciduous?
It behaves as a semi-evergreen in mild districts, holding much of its foliage year round, and drops more heavily in cold winters. It is rarely fully bare.
How big does Alnus jorullensis grow?
It reaches 15 to 20 metres tall and 10 to 15 metres wide. It is a large tree suited to acreage, avenues and parkland rather than small suburban blocks.
Does it tolerate wet ground?
Yes. Like other alders it handles wet and periodically waterlogged soils well, which makes it useful along drainage lines and in low-lying positions.
Does Alnus jorullensis improve soil?
Yes. Alders fix atmospheric nitrogen through root nodules, which improves depleted soils. This makes the species useful in rehabilitation and shelterbelt planting.
Is the Mexican Alder frost hardy?
Yes. It survives heavy and frequent frost without damage, though heavier leaf drop occurs after cold winters.
How far apart should I plant it for an avenue?
Plant 8 to 10 metres apart for an avenue, and keep trees at least 10 metres from buildings, paving and services given the fast growth and eventual size.