Is the Dwarf Chrysanthemum Poisonous?

Defining Dwarf Chrysanthemum

• Several popular garden mum species contain dwarf varieties, and some species are naturally of short stature, but none is consistently referred to as "dwarf chrysanthemum." Hardy garden mums (Chrysanthemum morifolium) varieties, which are hardy in United States Department of Agriculture plant hardiness zones 5 through 9, grow from 1 to 3 feet high and those offered as "cushion mums" can grow or be pinched back to maintain mounds under 2 feet in height and width. Garden mums (Chrysanthemum x grandiflora, alt. Dendrathema x grandiflora) naturally dwarf. Hardy in zones 8 through 10, foliage reaches 6 inches, and flowers add another 1 to 12 inches in height. Miyabe daisy "White Bomb" (Chrysanthemum weyrichii "White Bomb") reaches 12 to 24 inches in height and is hardy in USDA zones 4 through 9. Cornell University Extension notes that new varieties are bred so rapidly that you will find a number of local varieties suited specifically to your growing conditions.

Toxic Elements

• Chrysanthemums contain a natural insecticide called pyrethrum, in varying amounts. While particular species of chrysanthemum, specifically Dalmatian (Chrysanthemum cinerariaefolium) and Persian or pyrethrym daisy (Chrysanthemum coccineum), are cultivated for commercial pyrethrum production in USDA zones 3 through 7, horticulturalists and animal specialists warn home gardeners that all chrysanthemum varieties may possess toxic pyrethrum-based properties. These toxins can be particularly hazardous to children and pets because of their relatively small size. Pyrethrum attacks the nervous system of insects, producing paralysis on contact; effectiveness is determined by insect resistance and strengh of dosage.

Human Reactions

• The University of Arkansas Extension classifies hardy garden mums (Chrysanthemum morifolium) as a Category 3 toxic plant, on a scale of 4, with 1 being the most toxic and 4 being generally non-toxic. Reactive symptoms can include allergic dermatitis and mild to moderate stomach upset. High amounts of inhaled pyrethrum can produce asthmatic breathing, headache, tremors and incoordination. Symptoms can be more severe in children, especially infants.

Animal Reactions

• According to the American Society for the Prevention of Cruelty to Animals, all chrysanthemums are toxic to horses, dogs and cats. Symptoms include dermatitis, hypersalivation, diarrhea, vomiting and coordination problems. Clinical tests of high concentrations of pyrethrum confirmed potential liver damage in mammals.

Managing Mums in Your Landscape

• For adults, work gloves and thorough hand-washing address possible dermatitis problems. Discard mums if you experience breathing problems or nausea when working with them. Plant them behind border plants to make access to them harder for children, or put them in tall planters, where they cannot be reached by young children or pets. You should, as with any other allergic reaction, seek medical advice for symptoms or in case leaves or flowers may have been ingested.