Establishing a nursery for cut flowers is a foundational step in the commercial production of floriculture crops. In Kenya, where floriculture is a key contributor to agricultural exports and local employment, the success of cut flower farming heavily depends on the careful selection and preparation of the nursery site. This chapter explores the critical considerations in selecting an appropriate nursery site, the definition of cut flowers in the horticultural context, and the tools and equipment necessary for nursery establishment. Understanding these aspects equips horticulture professionals with the practical knowledge to optimize nursery productivity and flower quality.

1.1 Nursery Site Selection

Nursery site selection is a strategic decision that affects the growth, health, and yield of cut flowers. In Kenya's diverse agro-climatic zones, choosing the right location involves balancing environmental conditions with logistical and economic factors. For example, a SACCO-backed flower group in Limuru that must choose between a waterlogged valley bottom and a gently sloping, well-drained plot will find that the sloping plot gives healthier seedlings, lower disease pressure and fewer losses, even if the valley land is cheaper or closer to the road.

1.1.1 Definition of cut flowers

Cut flowers are fresh flowers harvested from plants and intended for ornamental use, usually in floral arrangements or bouquets. They are distinguished from potted or garden plants because they are grown specifically for their blooms to be cut and sold. The quality of cut flowers depends on attributes such as vase life, freshness, colour, and stem length, which are influenced by cultivation practices starting at the nursery stage.

Cut flower crops are established from nursery-raised planting material such as seedlings from seed, splits and suckers. The health and vigour of the young plants that leave the nursery therefore shape the quality of the stems harvested months or years later, which is why the nursery site matters.

Characteristics of Cut Flowers

• Freshness and Longevity: Cut flowers must maintain freshness for several days after harvesting to meet market standards in local flower markets or export destinations.
• Stem Strength and Length: Strong, long stems are essential for arranging flowers and for transportation durability.
• Uniformity and Appearance: Flowers should exhibit uniform size, colour, and shape to appeal to buyers in retail outlets and hotels.
• Disease-Free Quality: Cut flowers must be free from pests and diseases to ensure they do not deteriorate quickly or infect other plants.
• Continuous Flowering: Crops such as roses and alstroemeria flower repeatedly, so a good plant keeps producing marketable stems for years and harvests can be planned for market dates.

Examples of cut flowers grown from nursery-raised material include roses, carnations and alstroemeria, each requiring tailored nursery conditions to thrive.

1.1.2 Importance of nursery site selection

Selecting a nursery site is not merely a matter of available land. It involves critical decisions that determine the viability and sustainability of cut flower production. A well-chosen site helps avoid costly setbacks such as poor plant establishment, disease outbreaks, and low yields, and it guides horticulturists in making decisions that align with both agronomic and business goals. For example, an exporting company in Nanyuki that tests soil and checks water supply before building its nursery avoids replanting beds that fail in the first season.

Key Reasons for Careful Site Selection

• Optimising Growth Conditions: Understanding soil quality, water availability, and microclimate ensures plants receive ideal growing conditions from the first weeks of life.
• Reducing Pest and Disease Risks: Site history and neighbouring land use affect pest populations and disease pressure on young plants.
• Enhancing Operational Efficiency: Proximity to markets, labour availability, and infrastructure reduce production costs and post-harvest losses.
• Ensuring Environmental Compliance: Good drainage and proper waste disposal arrangements help meet environmental regulations, such as those enforced by NEMA, and avoid environmental degradation.
• Planning for Expansion: Evaluating site size and future land availability supports business growth without relocation disruptions.

1.1.3 Factors considered when siting a nursery

The selection of a nursery site involves multiple factors that collectively influence plant health and operational success. These factors encompass environmental, economic, and logistical aspects relevant to Kenya's horticultural landscape.

Environmental Factors

• Soil Type and Fertility: Well-drained loamy soils rich in organic matter are preferred to support root development and nutrient uptake. For example, the deep, well-drained red loams found around Kiambu are used for flower growing.
• Water Availability and Quality: Reliable access to clean water is essential for irrigation and misting, especially during dry seasons. Water should be low in salts (for young plants, an electrical conductivity ideally below about 0.75 mS/cm) and free from contaminants that can harm seedlings.
• Climate and Microclimate: Temperature, humidity, and sunlight exposure affect flowering and disease incidence. For example, Lake Naivasha lies at an altitude of about 1,900 m, which gives warm days and cool nights that suit rose production, though nurseries there still need frost and humidity control.
• Topography: Flat or gently sloping land facilitates drainage and ease of management while reducing erosion risks.
• Wind Protection: Sites with natural or artificial windbreaks prevent physical damage to delicate seedlings and reduce moisture loss.

Economic and Logistical Factors

• Accessibility to Markets and Inputs: Proximity to urban centres like Nairobi or Eldoret reduces transport costs for seedlings and cut flowers.
• Labour Availability and Costs: Areas with a pool of skilled or trainable workers reduce recruitment and training costs, while a site far from any settlement may need to provide worker transport.
• Infrastructure and Utilities: Availability of electricity, roads, and storage facilities supports nursery operations and post-harvest handling.
• Land Tenure and Legal Status: Secure land ownership or lease agreements prevent disputes and support long-term investment.
• Security: A fenced, secure site protects plants, tools and stored inputs from theft and damage.

Social and Environmental Considerations

• Community Relations: Sites near communities should consider potential conflicts, such as shared water sources and noise, and the social impact of the nursery.
• Protected and Sensitive Areas: Wetlands, riparian zones along rivers and forest edges are ecologically sensitive. A nursery sited on or beside them risks breaching environmental rules, so check requirements with NEMA and the county before settling on a plot.
• Flood and Frost History: Ask neighbours and local officers whether the plot has flooded or suffered frost in past seasons. Repeated flooding or frost makes a site unsuitable for tender seedlings.
• Sources of Pollution and Chemical Drift: Sites close to busy roads, factories or fields sprayed with chemicals may expose seedlings to dust, fumes or spray drift that damage young plants.
• Neighbouring Crops that Harbour Pests: Nearby fields of host crops can act as a continuous source of pests and diseases, so the distance and wind direction from such fields should be assessed.

1.1.4 Tools, equipment and materials used

Establishing a cut flower nursery requires specific tools and materials to clear and open the site, and to supply the plant material from which the crop is raised. The right selection and care of these items improves efficiency and the quality of the young plants. The table below summarises the hand tools and planting materials covered in this section.

1.1.4.1 Panga

The panga is a heavy, long-bladed steel knife used to cut woody growth. When a flower grower is inspecting or opening up a candidate nursery site, it is the first tool used to cut through shrubs and thick bush so the land can be assessed and cleared. For example, a bank-financed flower estate near Naivasha opening an old grazing paddock for a new nursery would use pangas to remove thorny shrubs before any other work begins.

Keep the blade sharp with a file, cut away from the body, and wear gloves and boots. After use, wipe the blade clean and dry, and store it in a sheath or on a rack to prevent rust and injury.

1.1.4.2 Jembe

The jembe is a broad, flat-bladed digging hoe and a widely used cultivation tool on Kenyan farms. On a prospective nursery site it is used to dig test holes to check soil depth, texture and drainage, and to loosen compacted ground and remove roots and stumps. For example, a technical training institute in Kiambu can dig a trial pit with a jembe to see whether the topsoil is deep and loamy enough for flower seedlings.

Keep the blade firmly fixed to the handle and sharpen the edge regularly. Clean off soil after use, since wet soil left on the blade causes rust and can carry diseases from one plot to another.

1.1.4.3 Slashers

A slasher is a long-handled tool with a sharp blade, swung low to cut grass, weeds and soft bush. It is lighter than a panga and suited to clearing large grassy areas quickly, including fence lines and the surroundings of the nursery where weeds can harbour pests. For example, a women's self-help group in Nyandarua could use slashers to cut tall grass around a chosen plot before marking out the nursery area.

Cut with a smooth side-to-side swing, keeping bystanders at a safe distance. Sharpen the blade often, and check that the handle is tight before use.

1.1.4.4 Rake

The rake has a row of steel tines on a long handle. In site work it is used to gather cut vegetation, stones and crop residues into heaps for removal, and to level and smooth the soil surface so that water does not collect in hollows. For example, a flower growers' cooperative in Kinangop can rake a cleared plot to see how evenly it slopes before deciding where to place the nursery beds.

Choose a rake with strong, evenly spaced tines. Clean it after each use, store it with the tines facing down or hung on a wall, and replace bent or broken tines to avoid injury.

1.1.4.5 Seeds

Seeds are the propagation material used for flowers that are raised from seed, such as statice, sunflower and snapdragon. Seed quality is decisive because it fixes the germination rate, the uniformity of the crop and the freshness of the plants that reach the market. For example, a hotel garden supplying its own flowers would buy certified seed from a reputable dealer rather than saving seed from weak plants.

Points to check when sourcing seed:

• Variety: Seed must be true to type and suited to the local climate and market.
• Germination percentage: Check the date of testing and the percentage stated on the packet.
• Health: Seed should be free from moulds, insect damage and seed-borne diseases.
• Purity: Seed lots should contain no weed seeds or foreign matter.
• Storage: Keep seed cool, dry and sealed until use, because heat and moisture quickly reduce viability.

1.1.4.6 Splits

Splits are portions of a mature plant that have been divided from the parent clump and carry their own roots and growing points. Dividing established plants gives new plants that are identical to the parent and often flower sooner than seedlings. For example, a girls' secondary school agribusiness club growing alstroemeria can lift a mature clump and divide the underground rhizomes into pieces, each with healthy roots and at least one shoot.

For good results, take splits only from healthy, vigorous mother plants that are true to type and free of pests and disease. Use a clean, sharp tool for dividing and keep the splits moist and shaded until they are set out. Avoid leaving them exposed to sun and wind, since drying kills the fine roots.

1.1.4.7 Suckers

Suckers are shoots that grow from the base or roots of a parent plant. Once they have developed their own roots or root buds, they can be separated and used as planting material. For example, a contractor-run flower farm growing heliconia can separate rooted shoots from the base of mother clumps and use them to produce new plants.

Select vigorous, medium-sized suckers from healthy mother plants. Separate them cleanly with a sharp, disinfected knife or spade to avoid tearing roots, and plant them soon after removal. Discard any sucker that is weak, damaged or showing signs of pests or disease.

1.1.5 Soil testing kit for assessing a nursery site

Beyond the clearing tools and planting materials above, the one additional item that directly supports site selection is a soil testing kit. It gives measured information on soil pH and nutrient status, so a grower can judge whether a plot is suitable before money is spent on bed construction. For example, a county-based agricultural extension officer advising a new grower can test samples from two candidate plots and recommend the one with the more suitable pH.

Procedure for sampling a candidate site:

1. Walk over the plot in a zigzag pattern and divide it into areas that look uniform in slope, colour and vegetation, because each area needs its own sample.
2. Clear surface litter, grass and stones from each sampling point so that only soil is collected.
3. Use the auger or a clean spade to take soil from the topsoil and root zone, to the depth at which the young plant roots will grow.
4. Collect several sub-samples from different points in the same area and place them in a clean plastic bucket.
5. Mix the sub-samples thoroughly, remove stones and roots, and take a portion as the sample for that area.
6. Label the sample with the plot name, area and date, and test it with the kit or send it to a laboratory.
7. Record the results and compare them with the needs of the intended crop before deciding whether to use the site.

Clean the auger and the kit after each use to avoid contaminating the next sample, and check the kit's reagents and instructions regularly so that readings stay accurate.

Chapter Summary

This chapter covers the establishment of a cut flowers nursery, beginning with the essential process of nursery site selection. It explains what cut flowers are and highlights the critical questions to consider when choosing a suitable site. The factors influencing site selection are examined alongside the tools, equipment, and materials required, such as pangas, jembes, slashers, rakes, seeds, splits, and suckers. The preparation of the nursery follows, detailing how to ready the land for planting. The chapter then addresses the proper methods for planting seeds within the nursery environment. Comprehensive nursery management practices are discussed, including mulching, shading, hardening off, watering, fertilizer application, pest and disease control, and pricking out to ensure healthy growth. Finally, practical steps for carrying out nursery bed preparation, planting, and ongoing management are outlined to support effective nursery operations.