Raising seedlings is the cheapest part of establishing a tree or coffee crop, and the easiest to lose. A prolonged dry season will destroy a nursery that would have survived a normal one, and the losses are almost always avoidable.
Site the nursery around water
The first decision is not what to plant, it is where the water is. A nursery more than a short carry from a reliable dry-season water source will not be watered adequately in the weeks that matter, whatever anyone intends in the planning meeting.
Look for: a water source that does not fail in the dry season, level or gently sloping ground, shelter from strong wind, and security from livestock.
Shade
Seedlings need a shade structure from the start, not once they begin to suffer. A simple frame of poles carrying grass thatch, palm fronds or shade netting is enough. Aim for dappled shade, roughly half sunlight.
Reduce the shade gradually in the weeks before transplanting, so the seedlings harden off. Moving a fully shaded seedling straight into open field sun is a common and complete loss.
Potting medium
Mix topsoil with well-rotted manure or compost, and sand if the soil is heavy, so it drains but still holds moisture. Fill bags firmly with no air pockets and no folded bottoms, which trap water and rot the roots.
Use bags large enough for the species. Coffee and tree seedlings held too long in undersized bags become root-bound and never establish well.
Watering
The single largest cause of dry-season loss is inconsistent watering, not insufficient watering.
- Water in the early morning or late afternoon. Midday watering loses much of it to evaporation and can scorch leaves.
- Water thoroughly enough that it reaches the bottom of the bag. Frequent light watering encourages shallow roots.
- Check by lifting a bag: a light bag is dry through, regardless of how the surface looks.
- Reduce frequency gradually before transplanting, to toughen the seedlings.
Name the person, not the group
A nursery watered by "the group" is watered by nobody on the day it matters. Assign a named person for each week, with a named substitute, and a book they sign. This one administrative step prevents more losses than any technical measure.
Reduce the water you need
- Mulch the surface of the bags with a thin layer of dry grass.
- Sink the bags partly into the ground, which keeps roots cooler and slows evaporation.
- Group bags tightly together so they shade one another.
- Windbreak the nursery, since wind dries bags faster than sun.
- Water into a shallow basin or channel rather than over the leaves.
Timing
Work backwards from the rains. Seedlings should be ready to transplant when the rains are established, not before. Sow so that the seedlings reach transplant size at that point.
Sowing too early means holding large seedlings through extra dry weeks, which is exactly the situation that kills nurseries. Sowing too late means transplanting into a shortening rainy season.
What if the rains fail after transplanting?
Keep some seedlings back in the nursery rather than planting out everything at once. A reserve lets you replace losses without starting again, and it is the cheapest insurance in the whole operation. Plan for perhaps a fifth held back.
Learning from a failed nursery
IDPN lost much of a coffee and cocoa nursery to a prolonged dry season, and the lessons were the ones above: water access decides the site, shade must be there from the beginning, watering must be somebody's named duty, and a reserve should be held back. Those changes are in the design of the next round.