Gleditsia triacanthos 'Sunburst'Honey locust

The compound, finely divided foliage opens golden yellow in spring, moves to yellowish-green tones in summer and returns to warm colours in autumn, ensuring continuous colour interest. The rounded, airy crown casts a light, luminous shade, which sets this cultivar apart from trees of dense shade: it lets through enough light to sustain lawn or massed shrub planting at the base, a decisive factor in an urban park or central reservation.

Unlike the straight species, armed with three-branched thorns and bearing long pods, 'Sunburst' derives from var. inermis and is practically free of thorns and fruit. This absence removes the risk to users and the mess of pods on the paving, qualifying it for street planting, squares and residential spaces where the straight species would not be viable.

In Portuguese conditions it reaches 10 to 15 m in height by 8 to 10 m in width, with moderate growth. It adapts to chalky, clay and poor sandy soils, as long as they are well drained, and does not tolerate prolonged waterlogging. It withstands heat, wind and moderate drought once established, and copes well with urban pollution, behaviour that supports its use in exposed city settings.

Full exposure is needed to maintain the intensity of the golden colour; in partial shade the foliage tends towards green. The genus is not among those under recognised plant-health pressure in Portugal, unlike Fraxinus with ash dieback or Platanus with canker stain, which simplifies its specification for avenue planting.

In avenue planting it occupies a register close to that of a Fraxinus or a lime, but with a more regular silhouette under formative pruning, better drought tolerance and without the plant-health exposure of the ash. The low maintenance requirement after establishment strengthens its place in municipal tree-planting projects.