Nursery management
Setting up and running a nursery: site, mother plants, structures, media, containers, plant health, hardening, records, and a seedling tray sum.
On this page
An orchard, a vegetable field or a forest plantation is only as good as the plants it starts with. A diseased, wrongly labelled or root-bound seedling can cost a grower years of lost production. Nurseries raise healthy, true-to-type planting material: grafted fruit trees, vegetable seedlings in trays, ornamental plants and tree seedlings for forestry and agroforestry. Nursery work is also a profitable enterprise in its own right, and a major source of rural employment.
Nursery establishment and management are standard horticulture exam topics.
Types of nurseries
- By crop: fruit, vegetable, ornamental and flower, forest and agroforestry, plantation crops (tea, coffee, rubber, cocoa).
- By duration: permanent nurseries with long-term infrastructure, and temporary or "flying" nurseries set up near planting sites.
- By product: seedlings, grafted or budded plants, rooted cuttings, tissue-cultured plantlets.
High-tech vegetable seedling nurseries, raising tomato, pepper, cucurbit and brassica transplants in plastic trays under protection, have grown rapidly worldwide because they give uniform, healthy seedlings and save farmers seed and time.
Site and layout
A good nursery site has:
- reliable, good-quality water (low salinity) for irrigation;
- well-drained, fertile soil, free from waterlogging and soil-borne pests;
- shelter from strong winds, with a windbreak if needed;
- road access for buyers and transport, and electricity;
- distance from orchards that might spread pests and diseases.
Mother plants and source material
The mother plant block (or scion bank) holds healthy, true-to-type plants of each variety, from which scions, budwood and cuttings are taken. Mother plants should come from certified sources, be clearly labelled and mapped, and be checked regularly for virus and other systemic diseases. Rootstock seed should come from known, healthy trees.
Structures
- Shade nets (often 35 to 50 per cent shade) for young seedlings and newly grafted plants.
- Polyhouses and mist chambers for rooting cuttings and healing grafts, which need high humidity.
- Insect-proof net houses for vegetable seedlings and virus-sensitive crops such as citrus and papaya.
- Raised seedbeds and benches that keep trays off the ground, improving drainage and hygiene.
- A potting yard, a store for media and tools, and a hardening area.
Media and containers
Growing media must be light, well drained, able to hold water and nutrients, and free of pests, pathogens and weed seeds:
- Soil, sand and well-decomposed manure or compost, often in equal parts, for polybags.
- Soilless media such as cocopeat, peat, vermiculite and perlite, especially for pro-trays.
- Sterilising soil-based media by solarisation (covering moist soil with clear plastic in hot weather for several weeks), steam, or approved chemicals reduces damping-off fungi, nematodes and weeds.
Containers:
- Polybags, the cheapest and most common for fruit plants, with drainage holes.
- Pro-trays (plug trays) with 50 to 200 cells for vegetable seedlings.
- Root trainers, with vertical ribs that direct roots downward and prevent spiralling, widely used for forest seedlings.
- Biodegradable pots.
Raising healthy plants
- Seed treatment with approved fungicides or biocontrol agents such as Trichoderma.
- Watering carefully: overwatering causes damping-off; drip, micro-sprinklers or boom irrigation give uniform supply.
- Nutrition with balanced fertilisers or fertigation.
- Plant protection: monitoring, yellow sticky traps, insect nets, and prompt removal of diseased plants. Many serious diseases, such as citrus greening, banana bunchy top and papaya ringspot, spread through infected planting material.
- Shifting and spacing containers to avoid crowding and roots growing into the ground.
- Hardening: gradually exposing plants to full sun, wind and less water for one to three weeks before dispatch, so they survive transplanting.
Records, labelling and certification
Each batch should carry a label with the variety, rootstock, date and source, and records should trace plants to mother plants. Many countries run nursery accreditation or certification schemes, with standards for mother plants, plant health, labelling and plant size, and require phytosanitary certificates for moving plants across borders. Selling misidentified plants damages a nursery's reputation for years.
Planning a vegetable seedling order
A nursery receives an order for 10,000 tomato seedlings, to be raised in 98-cell pro-trays. Experience shows 90 per cent of cells give a saleable seedling.
- Cells to sow = 10,000 ÷ 0.90 ≈ 11,112, so trays = 11,112 ÷ 98 ≈ 114 trays.
- With a cell volume of about 30 mL, each tray holds 98 × 30 = 2,940 mL, about 2.9 L of medium; 114 trays need 114 × 2.9 ≈ 335 L of mix.
- Hybrid tomato seed at about 300 seeds per gram: sowing one seed per cell needs 11,112 ÷ 300 ≈ 37 g of seed.
At a selling price of 0.05 dollars per seedling and costs of 0.03 dollars, the order earns 10,000 × (0.05 − 0.03) = 200 dollars gross margin, from about four to five weeks of bench space.
Key points
- Nurseries raise healthy, true-to-type planting material; types vary by crop, duration and product.
- Choose a site with good water, drainage, shelter and access; plan sections for mother plants, propagation, hardening, potting and dispatch.
- Keep certified, labelled mother plants free of viruses.
- Use clean media (soil mixes, cocopeat, peat, vermiculite, perlite) and suitable containers (polybags, pro-trays, root trainers).
- Prevent damping-off and pests, harden plants before sale, and keep labels and records; follow accreditation and phytosanitary rules.
What the exams ask
- School-leaving and entrance papers: what a nursery is, types of nurseries, and basic practices such as seedbeds and hardening.
- Degree and research-fellowship entrances: site selection and layout, mother plant management, media and sterilisation, containers, propagation structures, plant protection and certification.
- Professional and entrepreneurship examinations: nursery economics, planning production, accreditation and plant health regulation.
Described in general terms: the kind of examination, not a past paper. Laisha never reproduces exam questions.
Questions people ask
What is damping-off and how do I prevent it?
A disease, caused by soil fungi such as Pythium and Rhizoctonia, that rots seedlings at the soil line. Clean media, careful watering, good air movement and seed treatment prevent most losses.
Why harden seedlings before sale?
Plants raised under shade and frequent watering have soft tissues. Hardening thickens their cuticles and toughens them, so they cope with sun, wind and dry spells after transplanting.
Why do root trainers improve forest seedlings?
They direct roots downward and expose root tips to air at the bottom, preventing roots from spiralling in the container. Seedlings then develop strong, straight root systems after planting.
Sources
- Hartmann, H. T., Kester, D. E., Davies, F. T., Geneve, R. L. and Wilson, S. E. Hartmann and Kester's Plant Propagation: Principles and Practices, 9th edition. Pearson, 2018.
- Wilkinson, K. M. et al. (eds) Tropical Nursery Manual. USDA Forest Service Agriculture Handbook 732, 2014.
- FAO. Quality Declared Planting Material: Standards and Protocols for Vegetatively Propagated Crops. FAO Plant Production and Protection Paper 195, 2010.
- Landis, T. D. et al. The Container Tree Nursery Manual, volumes 1–7. USDA Forest Service Agriculture Handbook 674, 1989–2010.
- Macdonald, B. Practical Woody Plant Propagation for Nursery Growers. Timber Press, 1986.
More in horticulture
Discussion
Questions, corrections and notes from readers on this article. Every comment is checked before it appears: keep it on the topic, and do not share phone numbers, links or contact details.