CSLB C-27 Landscaping ContractorPlanting and LandscapingHard
A landscape architect specifies the use of California native plants for a new residential project to promote biodiversity and reduce water consumption. Which of the following is a key planting technique to ensure the successful establishment of these native plants, particularly in nutrient-poor or clay soils?
- ADeep cultivation of the soil to break up compaction and create a large basin for water retention.
- BPlanting in a raised mound or on a slope to ensure excellent drainage, avoiding over-amendment of native soil.
- CExtensive soil amendment with rich organic matter to improve fertility and water retention.
- DRegular application of high-nitrogen fertilizer during the first year to encourage rapid growth.
Show answer & explanationAnswer & explanation
Correct answer: B. Planting in a raised mound or on a slope to ensure excellent drainage, avoiding over-amendment of native soil.
Many California native plants are adapted to well-drained, often nutrient-poor soils. Extensive amendment of native clay soils can create a 'bathtub effect' where water pools, leading to root rot. Raised mounds or planting on slopes naturally improve drainage. Over-amending with rich organic matter can also lead to excessive growth and reduced drought tolerance in natives.
Why the other options are wrong
- A. Deep cultivation without proper drainage solutions can still lead to water pooling in compacted clay, and a basin design is generally counterproductive for drainage-loving natives.
- C. Extensive amendment, especially with rich organic matter, can be detrimental to many natives adapted to leaner soils and can lead to a 'bathtub effect' in clay, causing root rot.
- D. High-nitrogen fertilizer can cause excessive, weak growth in natives, reducing their natural drought tolerance and making them more susceptible to pests and diseases. Natives generally thrive with minimal fertilization.
Native Plant Planting
Techniques for establishing California native plants, focusing on appropriate soil preparation and drainage to mimic their natural habitat conditions.
- Prioritize drainage over fertility.
- Avoid excessive soil amendment.
- Minimal fertilization.
Memory trick: For 'natives' to thrive, give them 'drainage' and 'leave the soil alone'.