Environment

Question 1

What are the Positive impacts of horticulture on the
environment, to include:

Answer 1

• carbon storage in soils and plant tissue
• plant ecosystem services including air quality improvement, temperature, regulation, noise reduction, flood mitigation and water management
• biodiversity.

Question 2

What are the Negative impacts of horticulture, to include:

Answer 2

carbon footprint
* machinery emissions
* peat extraction
* single use plastic
* water management
* heating of glasshouses and structures
* waste and end of life impacts.

Question 3

What hort programs have environmental benefits?

Answer 3

• urban greening
• allotments
• domestic gardens
• parks
• botanical and
  heritage gardens.

Question 4

What are some Sustainable horticultural
practices to be aware of?

Answer 4

the carbon footprint of plants

• water management
• composting of green waste
• soil carbon management with no dig systems
• alternatives to plastics

Question 5

What is ‘biophilia’

Answer 5

Love of living things, like green areas (nature)

Humans have a deeply engrained love of nature which is an intuitive and natural drive imprinted into our DNA

Question 6

What are the benefits to the planet with hort.

Answer 6

1. photosynthesis producing the oxygen that life needs to breathe
2. Carbs for animals to eat
3. carbon being stored in longlived plants like trees, and in more indirect ways in the soil

Question 7

Lifecycle of trees in relation to carbon

Answer 7

1. 50% of dry weight of tree is carbon.
2. When tree dies/or burns Carbon returns to atmosphere.
3. Young absorb carbon; old pretty neutral; dead return carbon to atmspohere.
4. Healthy forest and grassland as well, are creating soil conditions that are putting a lot of the carbon produced during decay into the soil, and keeping it there.
5. Trees provide shade and urban cooling.
6. Soil carbon represents about 50% of the total carbon stored in forests

Soil carbon is considered very stable, meaning it does not change much over time. However if soils are
disturbed significantly, such as being ploughed or suffering erosion, or vegetation removed, then a series of developments occurs in the soil which
can result in a catastrophic loss of CO

Question 8

How are lawns for the environment?

Answer 8

1. Water
2. Fertilizer
3. pesticide
4. fertilizer
5. ugly

Question 9

How do peat soils deal with carbon sequestration

Answer 9

anaerobic conditions results in delayed decay. Over geological time these peatlands can become fossilised as coal deposits.

Question 10

How do plants affect carbon sequestration

Answer 10

grow more plants and in particular more trees, then we can at least do something about absorbing all this excess CO2 . Indeed, growing plants is the only practicable way of absorbing the excess CO2 we have put into the atmosphere since the Industrial Revolution.

Question 11

What can one mature absorb in 1 year?

Answer 11

22 kilograms of carbon dioxide from the atmosphere, and in exchange release
oxygen, in addition to removing a host of other pollutants, especially VOCs (volatile organic compounds, such as from car and domestic heating exhausts and industrial solvents).

Question 12

what do scientists atrribute the mini ice age to?

Answer 12

after 1492, when 90% of the population of the Americas died as a result of disease brought by European contact, may have resulted in the so-called ‘little ice age’ because so much CO2 was taken out of the atmosphere as trees recovered land de-forested by millennia of Native American agriculture

Question 13

What are other reasons for greening cities?

Answer 13

Heat Island affect - trees offer shade
Transpiration cools buildings
Trap dust/pollutants
Reduce noise

Question 14

Example of two plants that help with pollutants

Answer 14

camellias are very good at removing VOCs and
the plane tree Platanus x hispanica, a traditional street tree in many places is good at filtering out particulates

Conifers are good as they do this all year around.

Question 15

What plants could be of concern?

Answer 15

Cotoneaster is of concern as an invasive because several species smother rockfaces and the often rare plants that grow on them. However its flowers
are an incredible pollinator magnet and some species are particularly good at filtering particulates.

Question 16

What is and how to amend the heat island effect?

Answer 16

which will get considerably worse with climate change; cities heat up more than surrounding countryside, air quality deteriorates, and warm air is
pulled in from the surrounding, raising dust. Plants are the most effective way of reducing this problem: street trees, parks, green roofs, facade greening,
living walls

Question 17

What is the value of green roofs?

Answer 17

primarily to manage water runoff, especially from storms, and to do this effectively, complex meadow type vegetation with a substrate of around 20-30 cms is far more useful than the thin layers of sedums often seen.

Question 18

What is facade greening?

Answer 18

large climbers usually rooted into the ground, grow up support systems can be used to shade and insulate buildings. Living walls, where plants are growing in an irrigated material on a vertical surface can be spectacular, but are notoriously expensive to both build and maintain, but in dense urban environments they can make a significant contribution to air quality.

Question 19

What is SUDS

Answer 19

Sustainable Urban Drainage Scheme

Question 20

How do SUDS work?

Answer 20

Integrated green roofs, Detention basins (Swales, rain gardens) and pocket gardens hold water until it drains into soil, no runoff.

Question 21

Example of a green buildling

Answer 21

ACROS in Japan. Eco-friendly hall covered by terraced gardens & host to symphony orchestras & trade exhibitions.

Question 22

Negative impact of Hort from Energy use

Answer 22

fossil fuels to heat glasshouses, perhaps to grow crops out of season, plants from warmer climates, or for propagation.

19th c. used cheap coal to fuel the widespread practice of growing what became known as ‘bedding plants’

Question 23

How to reduce footprint of polytunnels/glasshouses

Answer 23

Technologies will help: nighttime thermal curtains, ground source heating, solar panels.

Question 24

How does transport affect environment?

Answer 24

plants being shipped around the world,
materials such as growing media and pots, landscaping materials like paving stone,
garden and landscape designers and maintenance staff travelling to their clients

Question 25

How does size of plant make a difference?

Answer 25

Larger pots
More soil
Heavier
More transport required

Question 26

How does Transport affect envirnomental issues

Answer 26

Indiv trips to garden center (online uses eco systems computer-led journey planning)

Long distances for trees from afar

Garden hardscaping moving around

Designers traveling around the world

Larger plants need more transport - something that begin in 19th c.

Question 27

How does garden maintenance affect the environment

Answer 27

Noise from equipment
Air pollution

Question 28

How to deal with maintenance issues in the future?

Answer 28

Battery operated
Accept weeds more
Reduce less use; mowing less
Accept nature and promote biodiversity with a more relaxed management styles. (Considered untidy)

Question 29

What design can help to provide more relaxed mgmt styles.

Answer 29

clipped hedges or shrubs combined with occasionally-cut meadow grass, makes it obvious that the lack of cutting is intentional rather than neglectful.

Question 30

What is one of the worst recently used methods that is unsustainable

Answer 30

Use of mature trees - transported long distances.

they rarely establish as well, or as quickly as smaller specimens

Question 31

carbon cost of moving plants around, is not transporting the plant, but

Answer 31

Substrate. Lighter composts do not cost so much to transport.

Peat, coir not goo

the use of composted green waste or wood
instead. substrates based on composted materials have the advantage that they can be produced almost anywhere, close to where they
might be used.

Question 32

How does water affect the environment

Answer 32

heavily connected to cultural expectations about having green lawns and lush gardens.

Xeriscaping: minimise wasteful features like lawns, or to find substitutes for them with plants that do not need much irrigation

soil improvement so that water is held better in the ground,

the use of mulches to reduce evaporation loss and water-wasting weeds, and

designs that maximise shade.

Question 33

How to provide water for the garden?

Answer 33

Water butts
Rain gardens
Grey water

Question 34

How do materials affect environment?

Answer 34

Plastic pots - Indiv can reuse; producers can’t (but are finding ways to recycle)
Polytunnels - only last 10 years
landscape fabric = suffocates soil

Question 35

What questions should horts ask when purchasing?

Answer 35

How far plant travelled? (can i reduce this? How much CO2 has been emitted)

producers are unwilling to make changes which involve greater costs and greater risks.

Gov’t has stepped in: Peat is an example

Question 36

What are the sustainable hort practices to be aware of?

Answer 36

• the carbon footprint of plants
• water management
• composting of green waste
• soil carbon management with no dig
  systems
• alternatives to plastics.

Question 37

What are the important aspects of urban trees?

Answer 37

1. Reduce urban heat islands
2. Carbon sequestration
3. Reduce air pollution
4. Dust trapping
5. Reduction in noise
6. Reduction in stormwater runoff
7. Temperature reduction
8. Offering shade

Question 38

Why is underplanting good for the environment?

Answer 38

Adding in additional layers of vegetation
maximises the environmental benefits of the planting (carbon capture, rainwater runoff reduction) as well as providing far more habitat for wildlife.

Shrubs or even meadow planting works

Question 39

How to develop for safety?

Answer 39

Some trees, grasses bushes. Separated to feel more safe. Has many things but separated.

Question 40

What is the reason for green roofs?

Answer 40

A green roof holds onto water, releasing it slowly, but also a lot of it is then transpired back into the atmosphere, which is a far more natural process and that transpiration helps keep the building cool.

Green roofs can also play a role in making buildings more livable by helping keep them
cool.

Question 41

What is facade greening?

Answer 41

Green walls. Planting climbers etc. Keep building cool and warm in winter and offers photo/transp.

Question 42

What is the concept behind rain gardens?

Answer 42

No water leaves the property.

Water should soak into soil, or be evaporated
back into atmosphere

Question 43

What is hort sustainability all about?

Answer 43

reducing inputs and reducing harmful outputs

Question 44

THE LAWN

Answer 44

Poor sustainability.

1. Too much water
2. Too much Fertilizer
3. Constant mowing
4. Machine useage
5. lack of diversity
6. Weed abatement

Question 45

What to think of with carbon footprint?

Answer 45

Energy input
Transportation costs (distance/weight/volume)

Question 46

End of life impacts?

Answer 46

Lost materials
energy
pollution
landfill
Recycling
reusing items

Question 47

Irrigation wastage?

Answer 47

Sprinklers more wasteful than drip systems
Automatic systems wasteful - rain still watering
Apply water only as needed not automatically
Targeted irrigation is most important. get roots not leaves.

Question 48

How does fertilizer affect sustainability?

Answer 48

Use only minimum needed
Excess fertiliser results in leaching and runoff into water courses, which is a major cause of
pollution of streams and ponds downstream

Question 49

Ways to avoid irrigation?

Answer 49

mulching, soil improvement

Question 50

How to manage soil as carbon sink

Answer 50

NO till farming
NO till gardening

Question 51

What is sustainability auditing?

Answer 51

All aspects reviewed:
Plant production
plant growth
plant usage

We need to think about the inputs we use, and the outputs we produce, what’s called auditing, really chasing back the carbon footprint and the sustainability impacts of all of our gardening activities.

Question 52

Name THREE aspects of traditional horticultural practice that have a negative environmental impact, and briefly describe what these negative impacts are.

Answer 52

a. Purchasing large container plants that require the transport, often from far distances, in heavy trucks emit harmful pollutants into the atmosphere. Often these larger plants do not settle as well as younger plants, which adds further issues if the plants don’t survive. Using smaller, often bare root, plants is less of an environmental problem as they can be grown locally and transport is less of a problem.
b. Using peat as a medium for growing. Removing peat from its natural habitat will release C02 into the atmosphere. Peat takes many years to develop, so removing one of the greatest carbon sequestration systems is completely unsustainable. Additionally, removing peat also removes a natural habitat for wildlife.
c. Growing lawns has been a traditional practice for many years. However, the amount of water needed to keep the lawn green is wasteful, especially during droughts. Additionally, the fertilizers required to keep the lawn green often run off into streams causing pollutants to enter the waterways. Finally, using noisy, gas powered, equipment to mow the lawn weekly also has a negative environmental impact.

MODEL:

The extraction of peat for growing media results in degrading natural valuable
and often biodiverse habitat, and damage to a major CO2 sink.
The use of lightweight plastic containers at various stages of plant production
involves creating a huge amount of waste, as these cannot be recycled and
are not suitable for reuse, as least on any scale.
The growing of annual plants for ‘bedding out’ involves the use of a lot of
resources, both materials and energy for a short-term effect. These plantings
do give a lot of pleasure, but could be done more sustainably.

Question 53

What is the ‘urban heat island effect’ and how can trees help mitigate it?

Answer 53

The urban heat island effect is caused by the massive amounts of concrete, buildings and roadways in urban settings and a lack of trees, shrubs and greenery to help mitigate the temperature rises due to the absorption of the heat from the sun. Urban settings have become hotter than rural settings because of this problem. Without trees there is no way for photosynthesis and transpiration to take place which would help reduce the heat radiated from the roads and buildings. Adding trees to the area will provide shade, offer the cooling effect through transpiration

MODEL:
The ‘urban heat island effect’ is when cities become very hot, more so than
surrounding countryside, as a result of a number of effects, such as greater
heat absorption by hard materials, a lack of plants to cool through
transpiration. Plants, especially trees, can do a lot to reduce temperatures by
creating shade, and the cooling effect of transpiration.

Question 54

Briefly describe what is meant by: A GREEN ROOF

Answer 54

On a flat surface roof, using plants to help retain water and provide a cooling effect from transpiration. Plants that are meadow like are preferrable to sedums.

MODEL:
a green roof – a roof engineered to be able grow plants on it, typically in a
continuous substrate

Question 55

Briefly describe what is meant by A SWALE

Answer 55

a landscaped area with rocks and substrate that is often more sand than soil. The bioswale takes the runoff water from the roads, holds it in the swale and filters it back into the ground water. Additionally, the bioswale helps to remove pollutants from the rainwater runoff. Any water that overflows the swale will then filter into the storm drains without pollutants. Plants that are found in swales must be able to survive both drought and heavy rains. Bioswales here are run by the local government, not residences – those would be rain gardens. Is that true in the UK as well?

MODEL:
a landscaped depression designed to capture water during a storm, to hold it temporarily while it drains away. Planting needs to be successful during ‘normal’ conditions but to survive temporary flooding at any
time of year

Question 56

Briefly describe what is meant by facade greening

Answer 56

Façade greening is the procedure where one grows climbers up the side of buildings in order to provide a place for photosynthesis and transpiration to cool the building and local area.

MODEL:
the use of large climbing plants on walls or structures
linked to walls

Question 57

Briefly describe what is meant by a rain garden

Answer 57

A rain garden is a planted area built to hold rainwater away from the structures and allow it to soak back into the soil, rather than runoff into the roads and streams.
MODEL:
a planted area which is designed to capture water from rainfall and allow it to soak naturally into the ground rather than be drained off the area

Question 58

Imagine a plant in a container at the garden centre. Describe some of the issues you would need to know about it in order to assess its carbon footprint.

Answer 58

a. When looking at a plant in the garden centre its important to know the provenance of the plant. Checking the UK Passport and Phytosanitary Certificate would be most important to know the origination of the plant. If the plant has travelled far, its carbon footprint would be greater. Additionally, looking at the size of the plant will make a difference. The larger and heavier a plant is, the more of a carbon footprint it makes. Also, knowing the nursery and their procedures – as in pesticides, watering procedures will make a difference to the footprint. Look at the container, what is it made of. If plastic, has it been recycled or how has it been manufactured. What is the growing medium? If it’s peat or coir, it is a larger footprint than using wood based medium. Finally, what kind of plant is it and what was needed to produce it? Was the plant grown in a glasshouse with lights and heat? Finding a plant that is locally produced in an environmentally friendly environment, small size and good growing medium would be the preferable choice for sustainability purposes.

MODEL:
The container itself – how much energy and other resources were used in making and transporting it? Is is re-usable or re-cyclable?
The growing media – is based on peat? or made from materials that have been transported a long way? or from recycled materials within the region?
The plant. How much energy might have been used in its production? Many ornamental plants do start off in glasshouses, and it is not at all easy to assess
how sustainable different production methods are; however a good rule of
thumb might be that larger half-hardy plants sold in spring or early summer
will have take up more greenhouse space than small ones, so the latter would
be more sustainable.
Transport – how far has the plant come from its producing nursery? Again,
the larger the plant the more this will matter.

Question 59

Traditional horticultural practice emphasized a lot of digging. Modern practice emphasizes “no dig”. What are some of the benefits of no-dig cultivations.

Answer 59

a. Soil microbes stay in place and alive with minimal disturbance
b. Worms and other creatures (sometimes gophers!) help aerate the soil and pull nutrients and carbon deeper into the soil
c. Carbon remains in the soil rather than being released back into the atmosphere – which means carbon sequestration continues.
d. Less intensive labour means less overall cost and not as tiring for the body
e. No dig also involves the use of compost and mulches to keep the soil moist and full of nutrients. This reduces weeds (which can compete with plants) and loss of water and topsoil.

MODEL:
No-dig is a lot easier physically!
It is far less disruptive to soil life, some of which is very involved in the continual recycling of organic matter upon which a healthy soil depends.
Disturbing soil exposes organic matter to the air causing oxidation and CO2 release.
No-dig on the other hand contributes to a ‘carbon sink’.
No-dig usually involves mulching as an integral part of its management, the action of worms and other invertebrates dragging organic matter down
ensures good aeration, drainage channels for water and getting nutrients down to plant roots.

Question 60

Imagine that you are a gardener for a large private garden which has been run on relatively traditional lines. You want to persuade the owner that they could be managing it much more sustainably, which would also benefit biodiversity and save them money.
Using bullet points, outline some proposals that would be simple to implement which would not only make their garden practice more sustainable but also have other benefits, and describe what those benefits might be:

Answer 60

a. Reduce lawn area and plant meadows or at least reduce how often to mow. This would provide more space for wildlife and pollinators as well as reduce the amount of time watering/mowing and using fertilizers to keep it pristine.
b. Build a compost heap that incorporates all the non-woody cuttings and leaves from the property. By doing this you prevent the carbon footprint of having the leaves picked up from the city. Additionally, building and maintaining your own compost heap will provide you with unending natural, healthy and sustainable food for all the plants in the garden area rather than having to purchase compost or fertilizer.
c. Build a rainwater garden and include water butts. This would retain the water onsite and prevent run off. Additionally, the butts, attached to the gutter drains will hold rainwater for summer watering. This will reduce the cost of using water from the mains.
d. Change the bedding plants from only annuals to include some perennials to reduce the wastage of plants. Changing the bedding at least twice a year for annual displays disturbs the soil microbes and releases carbon. This is also time and labour intensive. By adding perennials the plants remain in place sequestering carbon, reduce the amount of digging in the space and provide beauty year round. This also helps reduce the labour costs to run the garden.
e. Use the no-dig method of gardening which will reduce the labour costs of the gardeners, keep the microbes happy and sequester carbon.
f. Incorporate the use of mulches and compost rather than using expensive fertilizers. Mulches and compost will not only feed the soil naturally, but they will also help to retain moisture and protect the topsoil.
g. Reduce the use of glasshouses for producing half hardy annuals. Use hardy annuals or perennials that can withstand the winter temperatures. This will reduce the amount of fossil fuels used and reduce the cost of purchasing that fuel.
h. If using plastic containers from nurseries, be sure to keep them and reuse them until they are no longer viable. This reduces the cost of purchasing new containers and also keeps plastic out of the landfill for a longer period of time.

MODEL:
* Reducing mowing, leaving some areas to grow longer grass for several
months – good biodiversity benefits, reduced CO2 from mowing, and if well planned, can be visually more attractive, especially if there are any attractive
wildflowers.
* Building an efficient compost heap, to receive non-woody material, and which is regularly turned, with the resulting compost being used where it will
be most beneficial, in terms of the most nutrient-demanding plants – the
vegetable garden and herbaceous borders.
* Reducing the number of greenhouse-grown bedding plants bought in
spring. Grow hardy annuals instead. This will reduce the carbon footprint of
these areas of the garden.
Introduce a no-dig and mulching regime in the vegetable and cut-flower
garden, which will result eventually in a healthier soil, which will be a better carbon sink.
* Re-using all plastic plant containers, as with care, these can be used for
many years. Surplus to be cleaned and offered to local small growers or other
gardeners. This will considerably help reduce the carbon footprint of the
garden.