Herbaceous perennials are plants that while perennial are non woody. The structure of these plants are different from woody plants. The herbaceous perennial has a root structure consisting of tubers, bulbs, or rhizomes these help to store the food for next years growth andÃ‚ provide for new shoots and leaves to form each year. They die back each year and emerge the following year.
Most perennials can be purchased in quart or gallon containers or as bare root stock. The containerized plants allows for the planting of these plants throughout the growing season. Bare root stock must be planted in the spring within a couple of weeks of purchase. The advantage of containerized of course is that the plant is already growing and
has a head start. The earlier in the year that you can plant the better for it allows for the roots to become more established before the winter.When planted in the fall there is always the risk of the planted being uprooted by freeze thaw cycles.
Transplanting of most herbaceous perennials takes place in early spring as the plants are just starting to emerge if they are done latter in the season you should wait until after they have flowered and then cut them back about a half so they can reestablish themselves with out support all the growth. You may also have to shade these plants for a week or so if they have been moved late in the season.
A necessary maintenance tasks with herbaceous perennials is division. There really is no hard and fast rule about when a plant needs to be divided. Rather than say every three years or 5 years I tell people to watch for signs . The center of the plant nay start to die out while the outer edges are growing strong, You may find the plants flowers are becoming fewer and smaller or that the plant is starting to flop over. It may also be that the plant has just outgrown the area allotted to it. What ever the reason it is a really simple process just dig all around the plant until you can lift it out of the ground. Take the clump and then use a shovel or sharp knife to cut the clump into pieces the size of a quart container and replant. You should trim out any dead spots or broken roots then keep it moist and shaded for a few days. Most herbaceous perennials should be divided in early spring but some such as dayliles and hostas do well if divided in late summer right after flowering. While the thought of cutting up your plants may seem daunting to you let me assure you it is much more traumatic for you then your plants.
To assure that your herbaceous perennials do well remember to remove dead leaves and stems in the fall and to cover the plants with mulchÃ‚ for the winter.