Week 2 – Soil, Plant Production & Urban Tree Establishment

• Overview

This week focused on the importance of soil as a fundamental component of landscape design, alongside understanding how trees are produced and established for urban environments. Soil was introduced as a living, dynamic system that supports plant growth and wider ecological processes.

The session also explored how trees are grown in nurseries and the different production systems used before they are planted on site.

• Key Learning – Soil as a System

One of the most important ideas from this lecture is that soil is not just “ground”, but a complex structure made up of solids, air, and water.

• Around 50% of soil is solid material, while the remaining space is filled with air and water

• Soil texture (sand, silt, clay) affects drainage, aeration, and plant growth

• Soil structure determines how water and air move through the ground

Urban environments often damage soil through:

• Compaction from construction

• Mixing of materials (e.g. rubble, concrete)

• Loss of organic matter

This can severely restrict root growth and reduce plant survival.

Soil composition showing the balance between solids, air and water

• Urban Soil Challenges

A key issue highlighted is that urban soils are rarely natural. They are often disturbed, compacted, or contaminated.

For example:

• Compacted soil prevents roots from growing

• Waterlogging can create low-oxygen conditions (gleying)

• Contaminated soils (e.g. brownfield sites) require treatment before planting

This shows that landscape architects must understand existing ground conditions before designing.

• Plant Production & Tree Establishment

The lecture also explored how trees are grown and prepared before being planted in urban landscapes.

Trees are typically produced using three main systems:

• Bare root – lightweight and cost-effective

• Rootball – soil kept around roots for protection

• Container-grown – can be planted year-round

Trees are often propagated through methods such as:

• Grafting or budding (to maintain consistent characteristics)

• Cuttings (producing identical clones)

This ensures uniformity in urban planting schemes, where consistency is important.

• Reflection (Link to My Design)

This lecture has changed how I think about the ground within my Woolwich site. Previously, I focused more on surface design, but this session highlighted that successful landscapes begin below ground level.

In my project, which aims to create a space for entrepreneurs along the riverfront, soil conditions will be critical in ensuring planting success. This includes:

• Considering soil compaction in high-traffic areas such as markets

• Designing planting zones that improve soil quality

• Selecting tree types that can tolerate urban and potentially contaminated conditions

Overall, this session reinforced that soil is not just a base layer, but a key design element that directly affects the success of the entire landscape.