Jacaranda trees in Fitzroy Street and Victoria Park are putting on their annual show.

Up high and on the ground are beautiful blooms.

Dubbo City Council's manager horticultural services Ian McAlister is among the throng enjoying their temporary presence.

"They appear in spring and early summer and last for up to two months," he said.

"The flower colour varies from soft blue through to mauve/blue and almost purple."

How the jacarandas came to be in the centre of the city is not entirely clear.

It is considered likely they were planted by staff of the former Dubbo Shire Council between 1971 and 1975.

Whoever planted them, probably knew they would survive.

"The jacaranda tree is a native of the dry, high plains of Brazil and Argentina and are well suited to hot and dry climates," Mr McAlister said.

But Dubbo's frosts can be a challenge for the trees that can grow to 15 metres high.

"It is frost tender when young but tolerates frost better once it grows above three metres in height," Mr McAlister said.

"If we get a run of heavy frosts they can get frost burn, but they generally recover.

"Trees in protected areas, such as Victoria Park, handle frost better than those more exposed say on streets."

The lacy green foliage of jacaranda trees turns yellow in autumn before falling.

"The lovely trumpet-shaped flowers appear before the leaves return, then drop to form a blue carpet underneath the tree," Mr McAlister said.