Establishing a nursery for cut flowers is a foundational step in the commercial production of floriculture crops in Kenya. The nursery acts as the initial growth environment for young plants before transplanting to the main production site. Selecting an appropriate site for the nursery significantly influences plant health, growth rates, and overall yield of cut flowers. For horticulture professionals, understanding the criteria and tools for site selection ensures optimal nursery performance and resource use efficiency.

1.1 Nursery site selection

Nursery site selection is a critical decision-making process that determines the success of cut flower production. The right site provides favourable environmental conditions, accessibility, and protection from pests and diseases, all of which contribute to healthy seedlings and economic viability. In Kenya, where climatic and soil conditions vary greatly, site selection must be tailored to local realities and market demands.

1.1.1 Definition of cut flowers

Cut flowers refer to freshly harvested flowers and flower buds intended for decorative use. They are cultivated specifically to be cut at their peak bloom and sold for ornamental purposes, including bouquets, floral arrangements, and ceremonial decorations. Example: a grower who raises rose and carnation seedlings in a nursery does so because the mature plants will later produce stems that are cut, graded and sold.

Characteristics of cut flowers

• Freshness at harvest: Cut flowers are harvested when buds or blooms are at their optimal stage to ensure longevity after cutting.
• Aesthetic appeal: High visual quality with vibrant colours and uniform shapes distinguishes cut flowers in the market.
• Shelf life: They possess a reasonable vase life, which varies by species and post-harvest handling.
• Fragility: Being delicate, cut flowers require careful handling and storage to prevent damage.
• Economic value: Cut flowers are high-value crops contributing significantly to Kenya's horticultural export sector.

Examples of cut flowers grown in Kenya

• Roses: Grown for their wide range of varieties and steady market demand.
• Carnations: Valued for their long vase life and colour diversity.
• Chrysanthemums: Valued for their abundant flowering and durability.
• Alstroemerias: Appreciated for their exotic appearance and extended shelf life.
• Gerberas: Known for vibrant colours and suitability for bouquets.

1.1.2 Importance of nursery site selection

The nursery is where every cut flower crop begins, so a poor site weakens the crop before it reaches the field or greenhouse. A well-chosen site gives seedlings the soil, water, light and protection they need, and it keeps running costs low. Example: a nursery placed on a waterlogged hollow will lose seedlings to root rot every rainy season, while the same crop on a gently sloping, well-drained plot establishes evenly.

Benefits of a well-sited nursery

• Healthy seedlings: Suitable soil and a favourable microclimate give strong roots and uniform growth, so seedlings are ready for transplanting on time.
• Lower production costs: Natural drainage, nearby water and good access reduce spending on irrigation, drainage works and transport of inputs.
• Reduced pest and disease pressure: A site away from infected flower fields and old disease-prone land lowers the need for repeated spraying.
• Easier management: Level or gently sloping land with clear paths makes bed preparation, watering and movement of seedlings quicker and safer.
• Better market competitiveness: Consistent seedling quality leads to consistent stem quality, and good access to transport keeps delivery times short.

Consequences of a poorly sited nursery

• Poor seedling vigour due to unsuitable soil or microclimate.
• Increased mortality rates from environmental stressors.
• Higher production costs from irrigation or pest control.
• Reduced market competitiveness due to inconsistent quality.
• Loss of investment from crop failure or poor yields.

1.1.3 Factors considered when siting a nursery

Selecting a nursery site involves evaluating multiple environmental and infrastructural factors. These factors determine the suitability of the location for nurturing high-quality cut flower seedlings under Kenyan conditions. Each factor should be checked on the ground before any land is cleared, for example by digging a test pit, observing where water stands after rain and measuring the distance to the water source.

Environmental factors

• Soil properties: Well-drained loamy soils rich in organic matter support root growth and moisture retention. A pH suited to the crop should also be confirmed.
• Climate: Moderate temperatures and humidity levels reduce stress on young plants; excessive heat or frost can be detrimental.
• Topography: Flat or gently sloping land facilitates water drainage and mechanical operations.
• Water availability: Proximity to a clean, reliable water source ensures consistent irrigation.
• Sunlight exposure: Adequate sunlight is necessary for photosynthesis but may require partial shading in hot regions.
• Wind exposure: Strong winds damage tender seedlings and dry out beds, so a site with natural or planted windbreaks is preferred.
• Pest and disease history: Land previously under crops with soil-borne diseases, or next to infected flower fields, raises the risk of losses.

Infrastructural considerations

• Accessibility: Roads and transport facilities ease movement of inputs and seedlings.
• Security: Protection against theft or vandalism safeguards nursery assets.
• Proximity to markets: Reduces transport time for cut flowers, preserving freshness.
• Availability of labour: Access to skilled nursery workers supports operational efficiency.
• Utilities: Access to electricity and storage facilities enhances nursery management.

1.1.4 Tools, equipment and materials used

Efficient nursery establishment and management depend on the correct tools, equipment, and materials. These items enable proper site clearing, planting, maintenance, and protection of cut flower seedlings. The table below lists the main items, and the sections that follow describe the hand tools and propagation materials named in the curriculum.

1.1.4.1 Panga

The panga is a heavy, single-edged cutting tool used to clear shrubs, tall weeds and small branches from a proposed nursery site. It is also used to cut stakes and pegs for marking out beds and fixing shade net posts. Example: before a flower nursery is laid out, workers use pangas to cut back the bush so the plot can be surveyed. Keep the blade sharp with a file, wipe it clean after use, apply a light film of oil and store it in a dry place with the blade covered.

1.1.4.2 Jembe

The jembe is a hand hoe with a broad, flat blade used for digging, loosening and moving soil. At the site selection stage it is used to dig a test pit to check soil depth, texture and drainage, and to open shallow channels that carry away surface water. Example: a pit about 60 cm deep dug with a jembe shows whether a hard pan or standing water lies below the topsoil. Clean soil from the blade after use, check that the handle is firmly fitted and store the jembe off the ground.

1.1.4.3 Slashers

A slasher is a long-handled cutting tool with a blade used to cut grass and soft weeds in a sweeping motion. It is used to clear the vegetation around the selected nursery area and to keep the boundaries and paths short and tidy, which removes hiding places for pests such as rodents and insects. Example: slashing the grass along the fence of a rose nursery reduces the cover available to pests. Sharpen the blade regularly, keep the handle tight and store the slasher dry to prevent rust.

1.1.4.4 Rake

The rake has a row of metal tines on a long handle and is used to gather cut vegetation, stones and other debris from a cleared site. It is also used to level and smooth the soil surface so that water does not collect in low spots. Example: after slashing and digging, a rake is drawn across the plot to leave an even surface for marking beds. Remove soil and plant material from the tines after use, straighten bent tines and hang the rake or store it with the tines facing down.

1.1.4.5 Seeds

Seeds are one of the main propagation materials for cut flower nurseries and are used for species that grow true from seed, such as zinnia, snapdragon and statice. The quality of seed decides the uniformity and vigour of the seedlings, so seed should come from a reliable supplier, be of known variety, and have a high germination rate. Example: a nursery operator checks the packet for variety, expiry date and germination percentage before buying. Store seed in a cool, dry place in sealed containers so that it keeps its viability until sowing.

1.1.4.6 Splits

Splits are sections of a mature clump that are divided from the mother plant, each carrying roots and at least one shoot or growing point. They are used for species that spread by rhizomes or clumps, such as alstroemeria and gerbera, and they give plants that are identical to the parent. Example: a healthy alstroemeria clump is lifted and divided into portions, each with several shoots and a good root system. Select vigorous, disease-free mother plants, cut with a clean, sterilised knife and plant the splits soon after division so that they do not dry out.

1.1.4.7 Suckers

Suckers are shoots that grow from the base or the roots of a mother plant and can be separated to produce new plants. In chrysanthemums, basal shoots arising from the stock plant are removed and used to raise new plants that are true to type. On grafted roses, however, suckers from the rootstock are unwanted and are removed rather than used for propagation. Choose strong suckers that have their own roots or are ready to root, cut them cleanly with a sterilised blade and keep them moist and shaded until they are planted.

Usage and maintenance of nursery equipment

• Seedling trays: Clean and disinfect trays after each use to prevent disease transmission. Handle carefully to avoid cracking.
• Watering cans: Use watering cans with fine rose nozzles to avoid soil erosion around seedlings. Rinse regularly to prevent clogging.
• Shade nets: Install shade nets securely to withstand windy conditions. Replace nets when torn or faded to maintain adequate shading.

Shade nets covering a garden area (Source: Wikimedia Commons)

• Soil mixers: After use, clean soil mixers to remove debris and avoid contamination. Lubricate moving parts to ensure smooth operation.
• Pruning shears: Sharpen blades regularly for clean cuts. Sterilise between uses to prevent spreading pathogens.

Chapter Summary

This chapter focused on establishing a cut flowers nursery, starting with the critical process of nursery site selection, which involves understanding what cut flowers are and evaluating key factors to choose the best location. Essential tools and materials such as panga, jembe, slashers, rakes, seeds, splits, and suckers were identified for effective nursery setup. The preparation of the nursery followed, emphasizing soil readiness and bed formation. Planting seeds in the nursery was addressed with attention to proper techniques that promote healthy germination. Nursery management practices were explored in detail, covering mulching, shading, hardening off, watering, fertilizer application, pest and disease control, and pricking out to ensure robust seedling development. Practical steps for nursery bed preparation and planting were outlined to guide hands-on activities. Finally, the chapter concluded with nursery bed management practices necessary to maintain optimal growing conditions for cut flowers.