We have our largest concentration of DL in a 5'D x 100' L bed in front of a picket fence bordering our front sidewalk. The town snow plow last winter, and a late winter flood- dislodged many of our DL, sabotaging my planting them in carefully chosen single color groups (yellow and red.) After the snows melted, we replanted the orphans wherever we could find a spot for them (in this unlabelled bed.) The result is that now, yellows are blooming here and there in areas where I want all red. So I devised this way to tag them for moving/reorganizing by color- after they bloom:
I grabbed a pocketful of red 'twist ties' at a market last week, and i devised 2 different ways to tie them for tagging red or yellow dl.
I twist the tie in the crotch of a branch of the dl stem so the tie doen't slide down the stem. For one color dl, i twist the 2 ends of the tie tightly around the stem crotch. To signify the other color of dl, i twist together, at a crotch, the very tips of the twist tie, essentially creating a loop.

I like using twist ties as opposed to yarn because i only need one hand to tie a twist tie. Do you have an easier way of doing tagging?(Not labelling with names.)

best,
mindy
www.cottonarboretum.com/