4 Introduction to Plants for Difficult Planting Situations
4 Introduction to Plants for Difficult Planting Situations
Learning Objectives
- Describe plant tolerance for difficult planting conditions.
Few landscapes and gardens will contain the perfect planting conditions. Environmental stress from variable combinations of light and moisture levels, exposure to wind and cold, soil characteristics, site slopes and drainage can create difficult situations for planting. Some plants will be better suited to tolerate environmental stress because of morphological and physiological adaptations developed in their native habitat. For example, Berberis buxifolia (box leaf barberry), Gleditsia triacanthos f. inermis (thornless honey locust), and Ginkgo biloba (maidenhair tree, ginkgo) are able to tolerate a fairly wide range of planting conditions. When planting in difficult situations such as the examples described below, select plants from similar habitats that are naturally adapted to grow under the existing conditions.
Sunny arid conditions
Environmental stress associated with arid (xeric) conditions can severely limit plant growth. Climate characteristics include full light exposure, high summer temperatures, low and unpredictable precipitation, and low humidity with drying winds. Soils with poor structure, minimal organic matter or soil biology and low water holding capacity and nutrient availability are common in arid conditions. Where hardiness is a limiting factor for plant selection, local regional native plants adapted to the existing climate, soils, and moisture regimes are often the most suitable choice.
Shallow, extensive root systems allow species such as Rudbeckia fulgida (black-eyed Susan) to survive in drought and poor soil conditions. Plant characteristics such as small, compound, and modified leaves and stems, and light or gray colored leaves with hairy or waxy surfaces reflect sunlight, moderate the temperature at the leaf surface, and reduce water loss. Achillea filipendulina ‘Gold Plate’ (Gold Plate yarrow), Artemisia schmidtiana (silver mound), Festuca ovina glauca (blue fescue), Rosa rugosa (rugosa rose), and Abies concolor (white fir) are some examples of plants with these characteristics. Read more about plant adaptations at this link to Plant Adaptations to Arid Environments [New Tab].
Shade
Shaded areas that may seem problematic are in fact ideal for plants that occur naturally in habitats with low light, such as woodlands and ravines. There are many shrubs, trees, climbers, bulbs, ferns, and ground cover plants that either tolerate or prefer partial to full shade. For example, evergreen species and cultivars of Rhododendron spp. prefer deep to part shade while Rhododendron Northern Lights Group (azalea) prefers full sun to part shade. Characteristics of shade plants such as branched habits, two-ranked leaf arrangement, and broad, thin leaf blades are suited to capture available light. A strategy of some herbaceous plants, such as Crocus cvs. (crocus) is to emerge early, flower, set seed