New Plant Problems on Impatiens

I checked with the University of Florida on the use of Imidacloprid at the reduced rare of 0.235 percent concentration on citrus to control the pysillid that causes citrus greening. The product can be used on citrus up to 6 feet in height and must be applied 2 weeks before the new growth to be effective. There are reports of colony collapse to bee colonies because of this product. Nothing should be sprayed when bees are flying and pollinating plants. I still remain leery of this product with its systemic action.

A new foliar disease is killing Impatiens walleriana and interspecific hybrids with Impatiens walleriana as a parent. The New Guinea Impatiens, Impatiens hawkeri are very tolerant of the foliar diseases. Plasmopara obducens, Downy Mildew, is the causal agent causing the destruction of the Impatiens. Symptoms are yellow to pale green foliage, and mild mottling. Advanced symptoms include: Stunting of plant growth and malformed leaves and flower buds, Foliage is downward curling and distorted, wilting, plant collapse, severe defoliation. Management practices should include: Sanitation and scouting, Rotation of effective fungicides with different modes of action, Homeowner fungicides include: Concern Copper Soap Fungicide, Fertilome Broad Spectrum Landscape & Garden Fungicide, Monterey Agri-Fos, Ortho Max Garden Disease Control, Southern Ag Liquid Copper Fungicide, Southern Ag Triple Action Neem Oil. Do not replant Impatiens into landscape beds where downy mildew was identified during the previous season.  You should water in the morning so foliage can dry out before evening.

Thanks to Margery Daughtrey of Cornell University, Syngenta, and Cheryl Ricker for bringing this to my attention.