Hawthorn Rust most often infects leaves and may lead to premature leaf drop. The bright yellow spots can make an entire plant appear yellow. Hawthorn rust may also form spindle-shaped galls on shoots. Disease prevention and control is the key to effective control. A program of hawthorn rust management is made up of two primary components—protective fungicide treatments and selection of disease resistant varieties. Elimination of juniper from an area can reduce disease but is neither a realistic nor desirable practice in urban landscapes. Close placement of the two hosts can, however, increase the severity of the disease. When dealing with susceptible hawthorn varieties, properly chosen and timed fungicide treatments will do an excellent job of managing rust diseases, keeping your plants healthy and attractive.