I want to fertilize my perennial garden, but I need to spray for insects, which should I do first?
I haven fertilized my perennial garden yet this season, but I see some plants have been chewed on plus my Columbines have gray mold on the leaves. Which should I do first, fertilize or spray insecticide/ mold control?
If the mold is black "sooty mold", it could be related an insect pest that puts out 'honeydew' excretions that the mold grows on. Control the pest and you will control the sooty mold without fungicides.
You can do the fertility and pest management simultaneously. but the pest control is maybe more urgent in order to avoid the pest infestation and mold infection progressing into advanced conditions which are harder to control.
Don't spray without good reason, identify the target pest and use appropriate and least toxic materials. For example if you see chewed leaves, is it old damage or current, is the feeding still in progress or has the caterpillar, if that's what it is, come and gone in the feeding stage of their life cycle. What mold do you observe? Are there growing conditions that you could correct for more air and light circulation, or if you are overhead watering is that what is contributing to the condition.
IPM is Integrated Pest Management, or you can alternately say Intelligent Plant Management. Know what you are working with and minimize pesticide use.