CSLB C-27 Landscaping ContractorPlanting and LandscapingMedium
A landscape contractor is tasked with renovating a client's backyard which includes several mature, established trees. To improve soil health and water penetration around these trees without disturbing their root systems, which soil amendment and application method would be most appropriate?
- AApplying a thick layer of raw manure directly to the soil surface.
- BInjecting liquid fertilizer into the root zone at high pressure.
- CIncorporating gypsum deeply into the soil using a power tiller.
- DTopdressing with a high-quality compost, avoiding contact with the trunk.
Show answer & explanationAnswer & explanation
Correct answer: D. Topdressing with a high-quality compost, avoiding contact with the trunk.
Topdressing with compost is an excellent way to improve soil health, structure, and water penetration around established trees. It adds organic matter, beneficial microbes, and nutrients without disturbing the delicate root system. Avoiding contact with the trunk prevents rot and pest issues.
Why the other options are wrong
- A. Raw manure can burn roots due to high nitrogen and salt content, and may contain weed seeds or pathogens; it should be composted first.
- B. High-pressure injection can damage roots and compact soil, and liquid fertilizer alone doesn't improve soil structure like organic amendments.
- C. Power tilling can severely damage the shallow feeder roots of established trees, leading to stress or decline.
Soil Amendment for Established Trees
Methods to improve soil health, structure, and water absorption around mature trees without causing root damage, primarily involving surface application of organic materials.
- Avoids disturbing established root systems.
- Improves soil structure, aeration, and water retention.
- Adds beneficial microorganisms and slow-release nutrients.
- Compost is a preferred amendment.
Memory trick: Tree's Treat: Compost on top, roots rejoice, no chop!