2.Growing Media

Question 1

Explain considerations when growing plants in containers.

Answer 1

• Restricted root volume
• Water retention and supply
• Drainage - Must have hole in pot
• Nutrient availability - correct amounts must be added as roots can not go in search for them
• Stability of compost – crumb structure needs to withstand constant wetting

Question 2

Why is soil not suitable for use with pot plants?

Answer 2

• The crumb structure will not allow for constant watering
• Pore space collapse and oxygen supply is restricted
• May contain weeds seeds/ pest and disease
• Variable unknown amount of nutrients
• Variable PH level

Question 3

Peat alternatives?

Answer 3

• Coir (coconut fibre)
• Garden compost
• Wood based – bark sawdust paper etc
• Locally available materials such as straw wool etc

Question 4

State the effects of growing acid-loving plants in alkaline soils.

Answer 4

• Calcifuges
• Stunted growth
• Lime-induced chlorosis
• Nutrient availability decreases which may result in deficiencies

Question 5

Name a situation for each different type of compost.

Answer 5

Multi-purpose composts

• Wide range of uses - low nutrient levels
• Raising seed, container planting

Ericaceous

• Lime free and suitable for Calcifuges
• Planting of Rhododendron

Seed composts

• First planting of seeds, low in nutrients as high levels would be harmful and could even prevent germination
• Good aeration and good moisture retention

Cuttings composts

• They require a high air-filled porosity
• A good mix - 50% of organic material such as composted bark and 50% of an opening material to provide good drainage such as perlite, coarse sand or grit

Question 6

Advantages and disadvantages of using peat?

Answer 6

Advantages –

• Light, cleaner to handle and easy to store
• Sterile - does not need sterilising
• Consistent
• Good open structure with good drainage/water retention capabilities
• Weed, pest and disease free

Disadvantages –

• Non renewable product, develops very slowly
• As the compost is light the staking of tall, heavy plants can be problematic
• It is often very difficult to re hydrate when dry

Question 7

Advantages and disadvantages of loam-based compost?

Answer 7

Advantages:

• Useful for plants that are to be in containers long term, such as shrubs, as it is very stable
• They have a high level of buffering which means they avoid fluctuating water and nutrient content
• Clay content of loam provides a longer supply of nutrients
• The weight of the loam provides stability for the container. Therefore good for outdoors as less likely to be blown over.
• Sterile loam used to prevent fungi and disease

Disadvantages:

• It’s hard to get a good quality loam to use as a base
• The weight does make the it difficult to move containers and not suitable for hanging baskets
• Expensive - needs to be sterilised
• Peat is often used - Non-renewable

Question 8

Advantages of loamless compost?

Answer 8

Advantages:

• Soilless - so do not need to be sterilised
• Light weight
• Cleaner to handle
• Cheaper – no sterilising
• Often no peat used

Question 9

Describe the characteristics of 4 distinct named types of growing media (excluding garden soil) used for plants in containers.

Answer 9

Coir based

• Lightweight
• High water-holding capacity with good porosity and air content
• pH neutral
• Low nutrient content
• Sustainable - waste product

Wood based

• Excellent drainage
• Low PH
• Suitable for potting seeds and growing plants on

Local authority green waste

• High nutrient content
• High PH
• Best used as a mulch

Composted bark based

• Bark is non-clumping with an open, stable structure and is well aerated
• Low water-holding capacity
• Variable pH value

Question 10

List 4 distinct problems associated with growing plants in containers.

Answer 10

• Plants can become root bound
• Containers can become difficult to move if they are large /blown over if the container is not heavy enough
• Permanent plantings require top dressing or repotting
• Plants need to be watered

Question 11

Identify 2 situations where growing plants in containers is more suitable than growing them in open ground.

Answer 11

• Tender plants can be placed in the correct situation for sunlight/shade, etc.
• Ericaceous plants can be grown in a growing media with a suitable pH
• Containers can be moved to avoid excess rainfall/frost etc
• Application of nutrients can be controlled when feeding plants

Question 12

What are the ingredients of loam-based seed compost?

Answer 12

• 2 parts by bulk medium loam (partially sterilised)
• 1 part bulk peat or peat substitute
• 1 part by bulk sand

Question 13

What are the ingredients of potting compost?

(for growing on)

Answer 13

• 7 parts bulky medium loam (partially sterilised)
• 3 part bulk peat or peat substitute
• 2 part by bulk sand

Question 14

What are the ingredients of ericaceous compost?

Answer 14

• 2 parts by bulk loam (partially sterilised)
• 1 part by bulk peat or peat substitute
• 1 part by bulk sand

Question 15

List the benefits of adding organic matter to a soil

Answer 15

• Increased activity of micro organisms
• Hummus is added - Soil structure improved (aeration/drainage)
• Water holding capacity improved
• Nutrients in soil are gradually increased

Question 16

List the Limitations of adding organic matter to a soil

Answer 16

• May be a source of plant pests - Larvee/eggs
• May contain plant disease - Fungi/Spores
• Manure may contain urea and ammonia which scorches plant roots

Question 17

State the difference between ‘green’ and ‘brown’ material

Answer 17

Green material

• Break down quickly
• Grasses, leaves, herbaceous plants, vegetable matter
• High nutrient content

Brown material

• Break down slowly
• Branches, stems, woody areas, cardboard, wood chippings
• Generally contain lignin - hard material
• Low nutrient content
• Have a good impact on soil structure

Question 18

List key examples of the types of compost

Answer 18

• Farmyard manure
• Garden compost
• Spent mushroom compost
• Local authority compost (green waste)

Question 19

List key examples of the types of mulch used

Answer 19

Organic - Generally improves plant growth, over time will add nutrients into soil

• Chipped/shredded bark (Often laid ontop of weed suppressant, prevents evaporation)
• Leaf mold (rotted leaves of deciduous tree’s- slow)
• Composted straw (Used as a mulch, prevents slugs and snails)
• Local authority compost
• Spent mushroom compost
• Green manure (Green leafy plants are grown as crop and then incorporated into soil)

Inorganic - Does not add nutrients but can improve temp/suppress weed growth

• Pebbles or gravel
• Slate
• Stone chippings
• Recycled glass
• Geo textile sheets

Question 20

Describe the process of composting to include; Site, Construction, Materials, Care

Answer 20

Site

• Compost bin should be away from main garden
• Sheltered area away from wind/ extreme temp
• Easy access for wheel barrow
• Either plastic container or slated wooden box

Construction

• 1 cubic meter is ideal
• Stand on soil to allow access for organisms
• Lid/cover is needed for warmth and to keep rain off

Materials

• A mixture of green:woody 1:2
• Only small amounts of grass cuttings
• Avoid perennial roots/ plants with disease or pests

Care

• Turned once a month to spread heat throughout and aid aeration
• Add water if it becomes dry

Question 21

List key methods of composting

Answer 21

• Composting bin/box
• Tumbler (small amounts only)
• Hot bed (good for tropical plants/fruits)
• Worm composting (highly fertile)

Question 22

Describe the term Humus and how it is made

Answer 22

• Jelly like substance, sticky and black
• Coats the soil particles
• It is what gives top soil it’s darker colour
• It is created by worms and other micro organisms breaking down organic matter

Question 23

State the key benefits of Humus

Answer 23

• Helps improve soil structure
• In a light sandy soil it helps bind particles together
• In a clay soil it helps to break down larger lumps creating a better crumb
• It has a ‘buffering’ effect and carries a small electrical charge, holding onto plant nutrients and preventing them from being leeched out of the soil
• Helps the soil to heat up quicker due to dark colour

Question 24

What is Farm yard manure and what are it’s uses and restrictions

Answer 24

• Most traditional method of composting
• A mixture of cow/horse faeces, urine and bedding material such as straw or woodchip
• Used as a soil conditioner to improve structure
• Can be used as a mulch if well rotted
• It has high levels of ammonia so if not broken down it can scorch plant roots
• Should be stored for a year before use - by this time it should be dark, crumbly and odorless
• Nutrient level is usually low but can vary drastically depending on a number of factors

Question 25

What is **Garden compost** and what are it's uses and restrictions

Answer 25

* Most effective way of recycling kitchen waste * Breakdown of organic matter as a result of worms or soil organisms * A mixture **garden and kitchen** waste * Used as a soil **conditioner to improve soil structure** * Can be added to other materials to make **potting compost** * Often **contains weed seeds** so (unless heated to a high temperature) it is not ideal for mulching

Question 26

What is **Spent mushroom compost** and what are it's uses and restrictions

Answer 26

* Not generally available to the public - **bi-product** of mushroom industry * Almost entirely made from **straw with some chalk** mixed in * Used as a soil **conditioner** * Can be used as a **mulch** * Can be used as a **replacement for lime** when increasing soil PH * It has high levels of **PH** so if not broken down it can scorch plant roots

Question 27

What is **Local authority compost** and what are it's uses and restrictions

Answer 27

* Often refereed to as ‘**Green waste**’ * Locally produced and often **free** * Essentially the same as garden waste but it is **heated to a high enough level to kill of weed seeds/disease** * Used as a soil **conditioner** * Can be used as a **mulch on boarders or pot plants** * Can be contaminated **small particles of plastic and glass**

Question 28

Describe the 3 steps in the **breaking down of organic matter**

Answer 28

* **First step -** Worms, moles or other large organisms eat the organic matter and excrete the remains * **Second step -** Fungi present in the soil feed and grow on the dead material, this helps to break down larger woody matter * **Third step -** Bacteria/ microorganisms eventually convert it to the nutrients that can be absorbed by the plants and Hummus

Question 29

Describe **Mulching** and explain why it is important

Answer 29

* Material added to **soil surface** which has a range of uses but generally **improves plant growth** * Bare soil **looses moisture rapidly** * Bare soil is prone to **capping and erosion** * **Ideally no bare soil should be visable** * **Decorative** finish * Prevent **weed** growth * Aid **moisture** retention * **Protect** soil surface * Improve soil **structure** as it is slowly incorporated

Question 30

What is **composting?**

Answer 30

* Breakdown of **garden and kitchen waste**, gradually decayed * Supplies **nutrients** * **High levels of hummus** help improve soil drainage, aeration and nutrient holding capacity * Contributes healthy **soil organisms**

Question 31

What **conditions** are needed when composting?

Answer 31

* Beneficial **organisms** are aerobic so require well aerated conditions * **Water** is needed but materials must never become to wet * **Oxygen** is needed so material must never become to compacted * Should be **covered** to keep out excess rain and retain heat * 1 part **green** 2 part **brown** - green will speed up process, brown will helps to keep open and aerated * **Heat** is needed and produced - may rise to 70'c but not high enough to kill pest/disease * Must be **turned** often

Question 32

Give an overview of how **comfrey tea** is made

Answer 32

* Produced from **plant not animal** material * **No cost** and no carbon footprint * Good source of **potassium** * Used for **liquid** feed Process * Wear gloves to protect from **irritants** * When plant has reached **60cm** (but before plant has flowered) cut it down to **5cm** above ground * **Chop** the leaves * Pack **900g** of leaves into hessian sack and suspend in **container** with a lid * Fill container with **water** and keep **warm** * **Stir** mixture, foaming indicated it is working * When it stops **foaming (after 4 weeks) draw of the liquid** * **Dilute** 1:10 Uses * Tomatoes, cucumbers - **flowering/fruiting plants** * **Folier** feed