When To Plant, Divide And Recover
Since at this time of the year we are especially concerned with fall planting and dividing, the principal perennials which are best handled at this time may be enumerated as follows: Anemone sylvestris (snowdrop anemone), Brunnera macrophylla (Anchusa myosotidiflora), Caltha palustris flore pleno (double-flowered marsh marigold), Convallaria majalis (lily-of-the-valley), epimedium (barren-wort), helleborus (Christmas rose), Lathyrus vernus (spring vetchling), Nepeta mussini and N. grandiflora, and paeonia (peony). To these one should also add adonis (pheasant’s eye), ere-murus (desert candle), Mertensia virginica (Virginia bluebells) and Papaver orientale (Oriental poppy). These latter plants are completely at rest by the end of summer, and August-September is the only safe period to transplant and divide them.