Once spring arrives, a reddish-brown structure will begin to grow out of the indent eventually producing orange, jelly-like telial horns.

The basidium then produces basidiospores, which are released via wind and rain to infect its aecial, deciduous host's plant tissues (leaves, twigs, fruit, petioles).

The aeciospores are released into the air by the combination of wind and low humidity and infect susceptible evergreen hosts from midsummer into early fall beginning its telial stage.

The gall increases in size throughout the summer and fall seasons so it can overwinter the spore bearing structures that will protrude out the following spring thus restarting the cycle.

The pathogen prefers humid and cloudy conditions for developing growth and the spores depend on rain and wind to be dispersed to its alternate host.

This does not guarantee safety as there have been cases reported of cedar-hawthorne rust spores traveling 15 miles to infect its complementary host.

There are also a multitude of different hawthorne varieties that have been bred for resistance, so choosing one of those is wise if a known susceptible evergreen host is growing nearby.