Part 4 Plants for Horticultural Applications
31 Seasonal Plants
Learning Objectives
- Describe seasonal plants common to the horticulture industry.
Planning combinations of woody and herbaceous plants with different life cycles and high visual impact generates year round interest in exterior and interior plantings. When visual interest is planned for one period such as early summer, borders and containers can have a poor appearance the rest of the year. Optimizing the use of grasses, bulbs, perennials, annuals, biennials, shrubs, climbers, and trees can provide a succession of plant forms, colours, textures, and habits throughout the seasons. In temperate regions, year round interest is maximized by selecting plants with at least two, and even three or four seasons of interest.
Conifers and broadleaf evergreens shrubs are often used for year round colour and spatial structure. For example, Taxus cuspidata ‘Capitata’ (upright yew) provides reliable winter colour and a framework that can be enhanced with other shapes, textures, and colours. On the other hand, a planting of broadleaf evergreens such as Skimmia japonica (Japanese skimmia) offers winter colour and structure as well as showy spring flowers and colourful fruit in the autumn. Distinctive plant shapes and the bark of trees such as Cryptomeria japonica (Japanese cedar) and Morus alba ‘Pendula’ or species with persistent fruit like Sorbus aucuparia (European mountain ash) also contribute structure and winter interest.
Practice
Recognize woody plants for winter interest.
Some deciduous shrubs and trees like Caryopteris x clandonensis (bluebeard), Cercidiphyllum japonicum (katsura), and Rhus typhina (staghorn sumac) have interesting branching patterns throughout all seasons. The bark and buds of Ribes sanguineum (flowering currant, winter currant), Magnolia x soulangeana (saucer magnolia), Liriodendron tulipifera, and Styrax japonicus (Japanese snowbell, Japanese snowcone) provide winter interest and interesting buds forecast the appearance of foliage and flowers. Climbers with variegated or textured foliage and colourful flowers like Actinidia kolomikta (actinitdia) and Campsis radicans (trumpet vine) also contribute vertical structure. View the images seasonal plant characteristics available at this link to the KPU Plant Database [New Tab].[1]
The appearance of plants before, during, and after flowering is an important consideration for planning seasonal interest. For example, the herbaceous specimen plant Gunnera manicata (gunnera, giant rhubarb) provides a bold shape and texture for at least half to perhaps three quarters of the year. With planning, the eye-catching winter stems and seed heads of grasses and perennial species such as Pennisetum alopecuroides (fountain grass), Pennisetum setaceum ‘Rubrum’ (red fountain grass), and Perovskia atriplicifolia (Russian sage) can serve as distractions from seasonal voids. Layering various heights of ground covers, bulbs, annuals and perennials u