Canadian Food Inspection Agency

Canadian Food Inspection Agency

November 15, 2005 12:06 ET

CFIA: Chrysanthemum White Rust Found In B.C., Agency Asks Public to Dispose of Chrysanthemums

OTTAWA, ONTARIO--(CCNMatthews - Nov. 15, 2005) - The Canadian Food Inspection Agency (CFIA) is asking home gardeners in British Columbia to dispose of their chrysanthemums this fall, to prevent the spread of Chrysanthemum White Rust (CWR), a serious fungal disease which affects the plants.

Through the late summer and fall, CWR was found in several commercial chrysanthemum growing facilities in British Columbia. While affected greenhouses and nurseries have been quarantined, a large portion of the crop had already been sold.

Therefore, the CFIA is asking those who have purchased a potted chrysanthemum not to plant it in your garden, and do not compost the plants in your backyard composter. Instead, once you have finished enjoying it, dispose of it with your household garbage. This disease requires green plant tissue to survive and by disposing of the plants, the disease will be destroyed.

If you planted chrysanthemums in your garden, it is recommended that you pull out the purchased plant plus any other chrysanthemums in your garden as a precaution. The disease spreads very quickly and easily from one chrysanthemum to another.

The first symptoms of white rust are whitish-yellow circular spots on the upper leaf surface. They vary in size from pinhead size to five millimeters across. As the infection develops, the spot becomes sunken and a whitish or buff-coloured pustule appears on the under surface of the leaf.

The disease survives inside the plant, so if a chrysanthemum with CWR survives the winter in the garden, it can spread the disease to other chrysanthemums and surrounding gardens or to commercial growers during the following year. It is also possible that other chrysanthemums in the garden have already been infected. Symptoms are not always obvious in the early stages of infection.

Following initial discovery of the diseased plants, the CFIA issued quarantine notices and placed destruction orders on infected plants. Traceback of movement of plants and cuttings have been carried out and efforts are being made to trace the origins of the outbreak. The disease could have severe trade and economic implications for our commercial chrysanthemum growers.

CWR affects a number of species of chrysanthemums including potted florist mums, cut mums and garden mums. It does not pose any threat to people or pets, nor does it affect any plants outside of the plant groups of Chrysanthemum, Dendranthema, and Leucanthemella. It will not affect your marguerite, painted or shasta daisies.

Contact Information

  • Minister's office
    Matt Tolley
    (613) 759-1059
    CFIA Media Relations
    (613) 228-6682