UMD Extension doesn't main a database of spray mixture information like application rates, and you'd need to check the label for any products used as to multi-ingredient compatibility concerns and the timing of application(s). Penn State Extension provides some detail regarding recommended herbicide selection for Lesser Celandine control, and their primary suggestion is to use glyphosate instead. Triclopyr can be used instead where desirable grasses are growing intermingled with the Celandine. They do not address MCPA or dicamba. We don't recommend using dicamba in any area where they may be roots of desirable trees or shrubs, as it can cause significant and permanent damage to them if the exposure is great enough.

If you are a licensed pesticide applicator and are managing Lesser Celandine for clients, we recommend you inquire with your county Extension office's Ag Agent or one of Extension's weed specialists, such as Kurt Vollmer and Kelly Nichols to see if they have tips for professionals (as HGIC focuses on home gardeners). Contact information for those two Agents is available on the linked pages.

Miri