Hi Sharon, I have been there! Well, I’ve been advised to go ahead and grab that yarrow when the flowers still look nice … besides that one seems to put out all season long unlike some of the others mentioned. Same with Comfrey; Doc said in a video take it all and in a few weeks it will be back in all its glory 🙂 For Monarda, the herb is the medicine and when in flower it is most potent but when you have no other option, I’d gather it. Something is better than nothing. And my opinion on the skullcap is take what you can get that still isn’t dry on top. Again, when in beginnings of flowering is best time to harvest; however, I would take some of the stems, selecting what is still viable/green on top and use the whole stem if I needed it. Those last two I’d only use when/if needed until next year …. or, I’d buy it online from a trusted source and not worry about the potency. (which i would always note on the jar that is was late harvest and probably weak medicinal).
Best of luck,
Dawn