A herbaceous perennial plant is defined as a non-woody plant which usually dies back to ground level and grows again from the rootstock each year.
These plants are sold in two forms:
- Herbaceous Plants
- Herbaceous Bulbs (Perennating/storage organs, corms or tubers) – specified separately
Traditionally herbaceous plants were supplied as clumps, dug from open ground production and wrapped to prevent damage and desiccation. Increasingly, herbaceous plants are supplied pot or container grown available throughout the year. More recently, herbaceous plants (as clumps or pot grown) are being lifted from field or container yard and held in a cold store for later planting, either into pots to grow on or into the ground. By this method, nursery work can be extended and landscape planting can take place when climate and ground conditions are easier than is often the case during the dormant season. During the growing season, all herbaceous plants are sold as green plants.
This group also includes ferns, grasses, sedges, marginals, aquatics, bulbs, corms, rhizomatous and tuberous plants, herbs and non-woody vigorous alpine plants, categorised as:
- non-woody, evergreen perennials which retain some leafy presence above ground during the winter months. e.g. Helleborus spp., Euphorbia spp., Bergenia spp.
- grasses and grass like plants, e.g. Stipa spp., Festuca spp., Galanthus spp.
- some sub-shrubs (defined as “shrub-like plants, but with the woody parts confined to the lower proportion of the plant”), e.g Helianthemum spp., Thymus spp..
The NPS further classifies herbaceous plants by:
- Root Protection
- Size of Container
- Minimum Spread
- Number of buds
- Method of Propagation
- Plant List
Each plant must be specified by giving its full BOTANICAL name. For full details of the specification terms used in naming plants see Trees.