R2111 2.1 Site appraisal and site-specific plants

Question 1

Plants suitable for sun

Answer 1

• Lavandula angustifolia*
• Phormium cookianum*

Question 2

Plants for salt-laden wind

Answer 2

• Griselinia littoralis*
• Armeria maritima*

Question 3

Plants for strong wind

Answer 3

• Pinus mugo*
• Phyllostachys nigra*

Question 4

Examples of microclimates?

Answer 4

Rain shadow (which is…), remains predominantly dry in all but the wettest weather. This is usually created by the house or other building or by overhanging trees and evergreen shrubs.

Frost pocket which is often low-lying ground where cold air collects at night (as it flows downhill) allowing frost to develop. It may also result from a barrier e.g. a wall or fence across a slope which impedes the downward flow of cold air.

Sun trap

Wind tunnel

Heavy shade

Question 5

Design responses to micro climates?

Answer 5

Rain shadow could be used for a patio, deck or seating area as it is a sheltered spot. The area could also be used for plants which thrive in dry conditions, e.g. Lavandula angustifolia and Helichrysum angustifolium.

To avoid a frost pocket, openings can be created in a hedge to allow frosty air to escape. If walls are being built across a slope it is essential that they are angled to allow frost to roll down past the wall.

Question 6

Physical factors that create microclimates?

Answer 6

Aspect

Buildings

Topography

Question 7

Factors which must be recorded when carrying out a site appraisal?

Answer 7

• The aspect of the site, north, east, south, west facing areas of the garden which create sun or shade
• Soil pH to identify if the soil is acidic, neutral or alkaline. This will affect the selection of plants for the garden
• Soil drainage to include any areas of wet or waterlogged soil as well as any dry areas
• Microclimates within the garden e.g. frost pockets at the base of a slope and sun traps near south facing walls
• Existing garden structures e.g. sheds, walls, fences and their condition
• Views out of the garden to include borrowed landscapes and fine views as well as any eyesores e.g. electricity pylons which can be seen from the garden
• Additional factors which were acceptable included; soil type, soil texture, contours, exposure, style of house.

Question 8

How are factors associated with soil assessed during a site appraisal?

Answer 8

Soil pH

Using a soil-testing kit, soil samples are taken from several inches deep at various points across the site to test for the degree of alkalinity or acidity of the soil.

Soil texture

Hand tests can be used to assess the texture of the soil i.e. taking a soil sample, moistening it and rolling it between the finger and thumb to make a ball and feel how smooth or gritty it is.

Soil drainage

Soil drainage can be assessed by digging a hole (at least 0.5m) which is then filled with water to see how long it takes to drain. Alternatively, the site can be observed to locate any damp patches, waterlogging or ‘indicator’ plants.

Question 9

What information is needed in site appraisal?

Answer 9

Soil

• Depth
• Texture
• pH

Drainage

Contours (extent of slopes)

Aspect & exposure

Micro-climate (include visual clues)

• Frost pockets
• Shade
• Rain shadows
• Sun traps
• Wind tunnels

​Visual assessment of external features

• Good views
• Eyesores
• Style of house