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Coffee: a good planting hole, mulch and organic matter.
For arabica coffee, the planting hole and the mulch matter more than most farmers expect. Kenyan research shows that hole size drives early growth and yield, and that manure affects bean grade. This guide sets out what that research found and what we still don’t have figures for.
The numbers that matter
The research findings are from Kenyan coffee research. The site and spacing figures come from a supplier’s agronomy page, so check them with the Coffee Research Institute or your county extension officer.
Size matters more than manure
Researchers planted a compact, disease-resistant arabica (Catimor) in holes of 15, 30, 45 and 60 cm, with farmyard manure making up 0, 25, 50, 75 or 100 percent of the mix with topsoil.
What they found
- Larger holes gave significantly more growth and clean coffee yield.
- The manure rate made no significant difference to yield or growth.
- The share of grade A beans fell as holes got bigger and rose with more manure.
What they concluded
Make holes at least 45 × 45 cm. Keep manure to no more than half the mix with topsoil, which they put at about one to two debes (20-litre tins) per hole.
The abstract reports no exact yield figures, so we can’t quote numbers. The study used a single cultivar at two sites.
Digging and filling
- Dig the holeA supplier’s guide suggests holes of 60 × 60 × 60 cm, above the 45 cm minimum from the trial.
- Fill four weeks aheadMix topsoil with farmyard manure or well-rotted coffee pulp, plus DAP, and refill the hole at least four weeks before planting.
- Choose good seedlingsPlant seedlings 30 to 40 cm tall, with 2 to 3 pairs of side branches, about 12 to 15 months old.
SOURCES: “EFFECT OF PLANTING HOLE SIZE AND FARM YARD MANURE RATES ON ESTABLISHMENT OF HIGH DENSITY ARABICA COFFEE” (RUIRU AND KORU, KENYA); GREENLIFE CROP CARE, COFFEE PRODUCTION (SUPPLIER PAGE)
Where and how far apart
- Altitude and rain. Arabica suits roughly 1,400 to 2,000 m, with at least 1,000 mm of rain a year.
- Temperature. The ideal is 18 to 24°C. Keep day maximums at or below 30°C and nights at or above 15°C.
- Soil. Plant in well-drained, airy soil at least 1.5 m deep, ideally rich in humus.
- Spacing. Traditional varieties go 2.75 × 2.75 m. Smallholders without spray roads can use 2 × 1 m on flat land. Ruiru 11 is planted at 2 × 2 m or 2 × 1 m, which is 2,500 to 3,300 trees per hectare.
- Shade. Plant shade trees before transplanting coffee.
These figures are from a supplier’s page. We have not found a soil pH recommendation for coffee that we could confirm, so we give none. Ask for a soil test.
SOURCE: GREENLIFE CROP CARE, COFFEE PRODUCTION (SUPPLIER PAGE)
Feeding the soil under the tree
Mulch conserves moisture, which matters most where rainfall is low.
- Materials. Sisal waste, coffee prunings, maize stalks and banana trash all work.
- Benefits listed. It conserves moisture, suppresses weeds, supplies nutrients, controls erosion, moderates soil temperature, and is linked to fewer coffee thrips.
- Organic alternatives to fertiliser. Coffee Research Foundation work reviewed residues, green manures and intercropping as ways to meet the tree’s nutrient needs. The abstract lists them without rates.
What a trial at Ruiru showed.
In a Kenyan trial combining irrigation, mulch and nitrogen fertiliser, fresh fruit yield per tree rose by 66 percent. The abstract reports the combination only, so the effect of mulch alone is not known.
SOURCES: GREENLIFE CROP CARE, COFFEE PRODUCTION (SUPPLIER PAGE); NJOROGE (2001), “SOIL FERTILITY MANAGEMENT IN KENYAN COFFEE” (ABSTRACT); “EFFECTS OF IRRIGATION, MULCH AND N-FERTILIZERS ON YIELD COMPONENTS OF ARABICA COFFEE IN KENYA” (ABSTRACT)
Fertiliser and pest programmes
We did not find a freely available Kenyan source for coffee manure and fertiliser rates per tree, so this page gives none. The KALRO bulletin Coffee Nutrition (Mburu, Minai and Luusa, Bulletin No. 001, 2017) covers nutrients, fertiliser and manure. Ask the Coffee Research Institute or your cooperative’s extension service for it, and for current disease and pest advice, including coffee berry disease and leaf rust.
Whatever programme you follow, base it on a soil test.
Questions people ask
How big should the planting hole be?
At least 45 × 45 cm, according to the Ruiru and Koru trial. A supplier’s guide suggests 60 × 60 × 60 cm.
How much manure goes in the hole?
No more than half the mix with topsoil, or about one to two debes per hole.
Can I use coffee pulp?
A supplier’s guide names well-rotted coffee pulp as an option for filling the hole. Compost it first.
What mulch can I use?
Coffee prunings, maize or banana trash, and sisal waste are all listed.
What fertiliser rates should I follow?
Follow your soil test and a Coffee Research Institute or KALRO recommendation. This page does not give per-tree rates.
Turn coffee pulp and prunings into compost
We help estates, factories and cooperatives set up composting for pulp, husks and farm waste.