The Purpose Quest

Exploration · Costa Rica

The beauty and ingenuity of agroecology

How soil, water, plants and animals work together in Costa Rica’s dry and humid tropics, and why the most sophisticated systems are often the most beautiful.

Why agroecology

Farms that work like ecosystems

Agroecology designs farms the way nature builds ecosystems: many species in layers, soil that is never bare, and cycles in which what one part leaves behind feeds another. Costa Rica is an ideal place to see this, because tropical dry forest and rainforest lie side by side in one small country.

~90%
less soil erosion when crops grow under mulch instead of after burning
< 10 years
for soils under regrowing tropical forest to reach 90% of old-growth levels
Dec–May
native trees in flower through the dry season

Principles

Four ideas behind good design

  1. 01

    Start with water

    Design the water cycle first: catch the rain, let it soak into the ground, store it and use it more than once. In a long dry season, stored water decides what can grow.

  2. 02

    Design for tomorrow’s climate

    Plant for the conditions of the coming decades, not the average of the past thirty years. The trees planted today will live through them.

  3. 03

    One system, not separate measures

    Crops, animals, soil, water and energy interlock. What one part leaves behind, another part lives on.

  4. 04

    Beauty and function together

    The most sophisticated systems are often the most beautiful: flowering fodder trees, water as mirror and habitat, paths that invite a walk.

Two climate worlds

Where the water is, and when it falls

Costa Rica packs very different climates into a small country. On the dry Pacific coast, water is the limit. Inland, water is plentiful and the work shifts to fighting fungi and weeds.

  • Central Guanacaste5 dry months
    1,800 mm
  • Turrialba, Atlantic slopesno dry season
    2,300 mm
  • West Nicoya, around Sámara4 dry months
    2,385 mm
  • Cahuita / Sixaola, Caribbeanno dry season
    2,470 mm
  • San Carlos plainsno dry season
    3,020 mm
  • Valle del General, Pérez Zeledón3 dry months
    3,050 mm
Annual rainfall and dry months by climate region, from Costa Rica’s national weather service IMN (high confidence). What separates the regions is less the annual total than the length of the dry season.

Dry Pacific

Tropical dry forest with four to five dry months. Clay-rich soils, fertile but hard and cracked in the dry season. The main task is to store and save water.

Humid inland

Little or no dry season. Acidic, leached soils, fungal diseases, more weeding and pruning. The bottleneck moves from water to work.

Around Sámara it rains about as much in a year as on the Atlantic slopes of Turrialba. The difference is the rhythm: only about 4% of it falls between December and March.

Same rain, different rhythm

Ingenuity

Small techniques, big effects

Some of the most effective ideas in agroecology are strikingly simple. Each one works with a natural process instead of against it.

  • 1,250 → 2,760

    kg of maize per hectare, year 1 to year 10

    Mulch instead of fire

    In the Quesungual system of Honduras, farmers prune the trees in their fields and leave the cuttings on the ground instead of burning. The mulch holds soil and water in place, and yields rise over the years.

    Source: FAO 2005

  • 1.16–2.78

    land equivalent ratio of milpa fields

    Many crops, one field

    Maize, beans and squash grown together in a milpa produce more than the same crops on separate plots. The land equivalent ratio measures the gain: 1.0 means no advantage.

    Source: Mota-Cruz et al. 2025; Padilla-Fidencio et al. 2022

  • 60–70%

    less water than watering by hand

    Clay pots that water from below

    Unglazed clay pots, or ollas, are buried next to the plants and filled with water, which seeps slowly through the walls to the roots. Ideal for herbs and vegetables, not for trees.

    Source: University of Arizona Extension

  • up to 40%

    less evaporation

    Shade for the pond

    Open ponds lose water to the sun every day. Planting shade along their east and west sides markedly reduces evaporation.

    Source: MEFCCA, COSUDE & CATIE 2018

  • 20–30%

    crude protein in madero negro leaves

    Fences that grow

    Cuttings of madero negro root into living fence posts. They carry pitahaya vines, give cattle protein-rich leaves and flower pink in the dry season.

    Source: Costa Rica Tree Atlas

  • 50%

    of open-field wind speed, ten hedge heights downwind

    Windbreaks that breathe

    A hedge works best when it lets 40–60% of the wind through and has no gaps, which would act like nozzles.

    Source: University of Nebraska Extension

  • ≈ 5 kg

    of waste per m² of larvae bed per day

    Waste into protein

    Larvae of the black soldier fly, native to the Americas, eat kitchen and harvest waste. They become feed for chickens and fish, and their residue goes to the compost.

    Source: Eawag 2017; UCR 2025

  • ≈ 22%

    of dry wood becomes biochar in about three hours

    Charcoal for the soil

    Prunings can be turned into biochar in a simple cone-shaped pit. It is not a fertiliser: it works best when charged in compost before it goes into the soil.

    Source: Cornelissen et al. 2016; CICA-UCR 2023

  • 75.6 → 95.6%

    fruit set without and with day visitors

    Night and day pollinators

    Pitahaya flowers at night. In a study in Yucatán, day visitors such as bees and beetles added to the work of night pollinators and raised fruit set.

    Source: Rocha et al. 2026, Yucatán

Design

A garden ordered by water

A classic principle of permaculture design: place each element by how much water and care it needs, from a small irrigated core by the house to forest that needs neither.

Zones ordered by dry-season water, from the house outward12345Outward: less water, less care

  1. Irrigated core

    Vegetables, herbs, nursery, compost, worm beds and larvae, close to the house.

    Water
    Roof water in tanks, drip lines and clay pots, reused greywater where permitted.
    Care
    Daily

  2. Orchard & forest garden

    Fruit trees in layers, with chickens and stingless bees.

    Water
    Young trees only, in their first one to three dry seasons.
    Care
    Weekly

  3. Rain-fed fields

    Maize, beans, squash, cassava and pigeon pea under mulch instead of fire.

    Water
    Rain only, sown with the first rains.
    Care
    Seasonal

  4. Forest edge

    Native useful trees planted into gaps and edges: fodder, timber, fruit.

    Water
    None.
    Care
    Occasional

  5. Forest & corridor

    Protected forest, stream banks and a corridor for wildlife: the land’s water sponge.

    Water
    None.
    Care
    Observe
A general design pattern. How large each zone can be depends on water, slope and the legal status of the land.

Beauty

The dry season becomes the flowering season

Native useful trees flower from December to May, exactly when the dry forest stands bare. Madero negro is living fence, mulch and fodder at once, and turns pink in the dry months.

  • MarañónAnacardium occidentale
  • Madero negroGliricidia sepium
  • MangoMangifera indica
  • PochotePachira quinata
  • PoróErythrina fusca
  • CaraoCassia grandis
  • Cortez amarilloHandroanthus ochraceus
  • Roble de sabanaTabebuia rosea
  • GuanacasteEnterolobium cyclocarpum
  • Guayacán realGuaiacum sanctum
  • TamarindoTamarindus indica
  • PitahayaSelenicereus spp.
Flowering months from the Costa Rica Tree Atlas and the Área de Conservación Guanacaste, poró from iNaturalist flowering records (medium confidence). Cortez amarillo opens all its flowers at once, about nine days after a cool day or a rain in the dry season, and they last only four to five days.

Animals

Building the cycle from the bottom up

The order follows three questions: how much water an animal needs, how high the legal hurdle is, and how much it closes the cycle.

  1. First

    Worms and black soldier fly larvae

    They turn kitchen and garden waste into compost and protein, and need almost no water.

  2. Then

    Chickens

    They turn larvae and leftovers into eggs and manure. Their feed is the catch: a hen eats about 130 g a day, and foraging covers only a small part.

  3. Alongside

    Stingless bees

    Native mariola bees pollinate and fascinate. In Costa Rica every meliponary must be registered, and colonies may not be bought or moved. A colony gives 1–2 kg of honey a year.

  4. With a cool room

    Oyster mushrooms

    They grow on harvest leftovers. Above about 36 °C green mould takes over, so in hot regions they need a cool room or the rainy season.

  5. Later, optional

    Pigs on deep litter

    They turn bedding into compost and save about 46 litres of water per pig per day compared with washed pens. But in Costa Rica even a single pig needs a veterinary operating certificate.

Wild neighbours

  • 114 bat species live in Costa Rica. They pollinate, spread seeds and eat insects.
  • 14 hummingbird species have been recorded on the Nicoya Peninsula.
  • Morpho butterflies are seen there all year, even in the dry season.
  • Fireflies peak in May, when the rains return.

What to avoid

Beautiful, but not here

Several favourite permaculture and garden plants are listed as invasive in Costa Rica, and some are toxic. Where research names a native alternative, it is given.

  • invasive

    Torch ginger

    Etlingera elatior

  • invasive

    Poró gigante

    Erythrina poeppigiana

    Instead Native Erythrina fusca in wet valley bottoms

  • invasive, fails in long dry seasons

    Velvet bean

    Mucuna pruriens

    Instead Jack bean (Canavalia ensiformis) as green manure

  • invasive

    Pinto peanut

    Arachis pintoi

  • invasive

    Ginger lily

    Hedychium coronarium

  • highly toxic

    Angel’s trumpet

    Brugmansia spp.

Time

What grows when

Vegetables within months, fruit within years, forest trees within decades. A living system matures in layers of time.

  • Vegetables & herbs
    within months of the first rains

    within months of the first rains

  • Root crops
    cassava after about 6 months, yam after 7–10

    cassava after about 6 months, yam after 7–10

  • Grafted fruit trees
    first harvests after 2–5 yearscashew peaks around year 7

    first harvests after 2–5 years cashew peaks around year 7

  • Grain under mulch
    no gain over burning in years 1–2yields rise from year 3

    no gain over burning in years 1–2 yields rise from year 3

  • Tamarind
    first fruit after 7–10 years

    first fruit after 7–10 years

  • Forest trees
    cortez amarillo and guayacán mature over decades

    cortez amarillo and guayacán mature over decades

Years after planting. Values are general for each species and system, not measurements from a particular site. Grain yields refer to the Quesungual system in Honduras.

Open questions

Questions worth exploring

  1. How will the dry season change?

    How long and how dry will dry seasons on the Pacific be by 2050? Climate projections are the next piece of research.

  2. How far can water be reused?

    Greywater, constructed wetlands and rain harvesting could close much of the water cycle. Which solutions work in the tropics, and within Costa Rica’s rules?

  3. Does syntropic farming work in long dry seasons?

    Most evidence comes from Brazil and Bolivia. On Costa Rica’s dry Pacific, only one hectare has been documented so far.

  4. Which natives can replace invasive favourites?

    Several popular ground covers and ornamentals are invasive in Costa Rica. Native alternatives are still thinly documented.

About the figures: they come from research carried out in September 2026, drawing on Costa Rica’s national weather service (IMN), FAO, CATIE, INTA, the University of Costa Rica, SINAC and peer-reviewed studies. Statements rated as low confidence are marked as estimates, and examples from outside Costa Rica are named as such.