Harvesting the African Marigolds is the easiest part of the process. You simply cut off the mature flowers. It is okay to pinch the blooms off with your fingers if you don’t have pruning shears handy. I left about 1” of stem attached to the flower. One problem I had at first was mistaking blooming flowers for dying ones, but I since learned that a bloom that looks like it’s dying may in fact just be getting ready to bloom.
The flowers can be used right away or stored for later. If you want to store the flowers, lay them out to dry first someplace dry and out of the way. It may take a few days. Just check the middle and if it is still squishy, even a little bit, give it another day or so to dry. Even the littlest amount of moisture can cause mold when you place your flowers in an air tight container for storage.
If I were harvesting in the wild (which I haven’t yet), I’d like to follow the principles of the honorable harvest. I learned about these principles in the book Braiding Sweetgrass by Robin Wall Kimmerer. The principles include never take the first one, ask permission, listen for the answer, use everything that you take, be grateful, minimize harm, share what you’ve taken, reciprocate the gift, and take only that which is given.
Although we have grown these flowers purposefully for dyeing, I think the principles can still apply.