This document discusses designing gardens for sustainability. It states that once the environmental impacts of a design are assessed, mitigation measures can be incorporated to reduce or eliminate negative impacts. For example, incorporating a rain garden can retain runoff and clean water before it drains, benefitting both the environment and design. When choosing materials, those with the lowest carbon, energy and water inputs and longest lifespan are most sustainable, such as FSC-certified wood. Sustainable maintenance practices like using compost and minimizing machinery can be planned from the beginning. The outcomes of the lesson are to understand how sustainability affects landscaping choices and how sustainable maintenance practices integrate into design.

1. RHS Level 2 Certificate
WEEK 25 PART 2 CHAPTER 2
SUSTAINABILITY IN GARDEN DESIGN – DESIGNING FOR SUSTAINABILITY.

2. Environmental Impact Design can
mitigate negative impacts
Once you have your impact assessment then the design can be used to reduce or
improve any long term or severe negative impacts.
As with risk assessment in health and safety, some impacts may be so severe that
the activity should not occur (removing an ancient Oak tree in order to build a patio,
for example). However for most, careful design can turn a negative into a positive.
For example – you have identified that serious water run-off into a watercourse is
likely to occur (due to changes in slope or hard landscaping). This will deposit soil,
road dust and pollutants, cause nuisance surface water flooding, etc.
Incorporating a rain garden or bog garden to retain the run off and clean the water
before it drains may be both a positive for the environment (for plants, insects and
amphibians) and for the design (an attractive new feature).

3. Sustainability - materials
Choose materials with lowest inputs – carbon, energy, water – and
longest life.
Wood – FSC certified, native wood most sustainable choice.
Stone – by-products of quarrying have lowest impact, imported stone
highest.
Use recycled or re-manufactured materials instead of new, but check
transport inputs. Recycle ‘arisings’ from the site rather than landfill them
– e.g. excess top soil used to recontour an area, chipping removed woody
plants for use as mulch.
Plants – plant according to the conditions, permanent planting has lower
inputs than bedding.

4. Sustainability - maintenance
Water – plan space for a water butt, include porous hose
irrigation, planting that needs minimal irrigation. Control of
water runoff.
Soil improvement – plan space for a composting area if
possible. Avoid bare soil to limit erosion and C02 emissions.
Planting – permanent planting uses fewer resources and
produces less waste than temporary displays. Bedding can be
minimised to reduce impacts – use of heat, water, fertilizer,
transport (if bought in) etc.
Machinery – reduce use of powered machinery e.g. wild
flower areas not lawn.

5. Outcomes
Check the outcomes – after this part of the lesson, can you?
1.5 Describe how the environmental sustainability of landscaping
materials may affect choices made during the planning and design
stage.
1.6 State how sustainable practices in the maintenance of a garden
can be integrated successfully during the planning and design stage

6. End of Part
Now review the ‘Sustainability in the Garden’ handout. You could
also read more about this approach to design in the additional
materials suggested.
Then click on the ‘Next’ button to see the exercise for this chapter.