What are green industries?
Green industries are businesses and jobs that grow plants, raise animals and look after land. Main sectors:
- Horticulture: fruit, vegetables, flowers, nursery and indoor plants.
- Agriculture: field crops (rice, wheat, maize) and livestock.
- Forestry: planting, managing and harvesting trees; protecting forests.
- Landscaping: designing, building and maintaining gardens, parks and green roofs.
- Turf and floristry: sports fields, golf greens, flower arranging and shops.
Careers include grower, arborist (tree specialist), landscape designer, greenkeeper, florist, forest ranger and agronomist (crop scientist). These industries also help the environment: they store carbon, cool cities and protect soil.
Factors affecting plant growth and product quality
Plants make food by photosynthesis. For this they need:
- Light: amount and hours of daylight. Too little gives tall, weak, pale plants.
- Water: too little causes wilting; too much drowns roots.
- Temperature: most crops grow best around 18–25 °C. Frost and heat waves damage them.
- Nutrients: nitrogen (N) for leaves, phosphorus (P) for roots and flowers, potassium (K) for overall health and fruit.
- CO₂ from air, and good air flow.
- Soil: texture (sand, silt, clay), organic matter, drainage, and pH (about 6–7 for most crops).
The factor in shortest supply is the limiting factor: adding more of the others does not help. Pests (insects), diseases (fungi, bacteria, viruses) and weeds reduce yield and quality. Integrated pest management (IPM) combines checking crops, helpful insects, clean tools and only targeted spraying.
Designs and processes: propagation and greenhouses
Propagation
- Sexual: from seed. Cheap, many plants, but offspring can differ from the parent.
- Asexual (vegetative): from a part of one plant, so the new plant is a copy. Methods: cuttings (stem, leaf), layering, division of clumps, and grafting or budding (joining a shoot to a rootstock). Tissue culture grows many copies in a lab.
Greenhouses and production
A greenhouse or polyhouse traps sunlight and heat. Vents, fans, shade nets, heaters and misters control temperature and humidity. Drip irrigation and fertigation (fertiliser in the water) save water. A production plan sets what to grow, when to sow, spacing, feeding, harvest dates and how to store and sell the product.
Landscape design
The design process:
- Site analysis: sun and shade, slope, soil, drainage, existing trees, views, and what the client wants and can spend.
- Concept: rough bubble diagram of areas (play, sitting, vegetables).
- Scale plan: a top-view drawing, for example 1 : 100 (1 cm on paper = 1 m on site).
- Build and maintain: hard landscape (paths, walls, ponds) first, then soft landscape (plants, turf).
Elements: line, form, colour, texture, scale. Principles: balance, unity, rhythm, focal point. Choose native, climate-suited plants to save water and support wildlife.
Maths, technology, communication and technical skills
Grower maths
- Area of a bed = length × width (m²).
- Plants needed = area × plants per m².
- Fertiliser = area × rate (g per m²).
- Mixing: a 1 : 4 ratio means 1 part concentrate to 4 parts water.
- Scale: 3 cm on a 1 : 100 plan = 3 m on site.
Technology and communication
Soil moisture sensors, timers, weather apps, GPS for tree mapping, and spreadsheets for records. Growers read product labels, write work orders and explain plans to clients.
Technical skills and safety
Pruning, planting, potting, mowing, safe use of hand and power tools, lifting with a straight back, gloves, eye and ear protection, and safe storage of chemicals.
Key formulas and definitions
- Area of rectangle bed = length × width (m²)
- Number of plants = area × plants per m²
- Fertiliser needed = area × rate (g/m²)
- Ratio 1 : n = 1 part concentrate + n parts water
- Plan scale 1 : 100 → 1 cm = 1 m
- Limiting factor: growth is set by the resource in shortest supply
Worked examples
1. A flower bed is 4 m × 3 m. You plant 4 plants per m². How many plants?
Area = 4 × 3 = 12 m². Plants = 12 × 4 = 48.
2. A lawn is 20 m × 15 m. Fertiliser rate is 30 g per m². How much fertiliser in kg?
Area = 300 m². Fertiliser = 300 × 30 = 9000 g = 9 kg.
3. A plant food must be mixed 1 : 4 with water. How much concentrate for 10 L of mix?
1 + 4 = 5 parts. 10 L ÷ 5 = 2 L per part. Concentrate = 2 L, water = 8 L.
4. On a 1 : 100 plan a path is 6.5 cm long. How long is it on site?
1 cm = 1 m, so 6.5 cm = 6.5 m.
5. Tomato seedlings in a dark corner are tall and pale even with plenty of water and fertiliser. Why?
Light is the limiting factor. Extra water and fertiliser do not help; move them to more light.
6. Why might a grower graft mango shoots onto a strong rootstock instead of growing from seed?
Grafted trees are copies of a good parent, so fruit quality is the same, and they fruit sooner. Seedlings can differ from the parent.
Common mistakes
- Thinking more fertiliser always means more growth. If light or water is limiting, extra fertiliser is wasted and can burn roots.
- Overwatering. Roots need air too; waterlogged soil kills plants.
- Expecting seedlings to be exact copies of the parent. Only vegetative propagation gives copies.
- Forgetting units: area in m², rates in g/m², and changing g to kg (÷ 1000).