Hot Monsoon Tropics Design

This is a Permaculture Design created for Green Circle farm in Singapore. Now provided here as a resource tool. Please enjoy.

The Green Circle Design

Intent: We wish to establish a food forest, pathways and a shallow wetland / pond with aquatic plants. We also wish to enhance the aesthetic value of the property and create spaces for people to enjoy Green circle’s organic Farm while doing workshops and tours.

The Green Circle Wetlands

Having a crenellated (flower shaped) pond in front of the property can greatly enhance the aesthetics and biodiversity of the land. There are Natural Methods that can be used in order to create a permanent aquaculture system. The wetlands can be a display of many native species that are being lost due to city development (like a sanctuary) along with plants that enhance the ecological system and that are functional for human uses. Large boulders, Logs and thick patches of marsh can improve animal habitat and beauty of the design.


There are numerous options in sealing the earth to build a pond. Because of your desire to be most natural, I recommend a method that will only use materials sourced from your farm.

The pond could be created with a method called gleying. In this process, we use organic matter to hermetically seal the ground. To Create your Wetlands:

  1. Begin the project when monsoon season is complete.
  2. Dredge a 40ft radius circle in the pond area about 3 feet deep.
  3. Create a 30 degree or less gradual slope for pond edges
  4. Select and area on the south east end for overflow drainage to be slightly lower then the rest of the pond edge
  5. Take banana leaves and papaya leaves and other similar sappy Succulent leaves to fill the pond 9 inches high going up the slightly sloping sides of the pond.
  6. Cover completely with 6 – 8 inches of the earth that was dredged out
  7. Seal the wetland floor by compacting the earth down tightly. (This creates an anaerobic fermentation that seals the bottom of the pond and also does not permit weeds to grow [permitting that we used weed free soil or clay to cover it.])
  8. Once the wetland floor is sealed (about a week) fill in the flower like chinapas with dirt to create the crenellated wetland design.
  9. Finish off edges to make sure overflow is properly in place and the design looks appealing.

10. Allow for rainy season to fill the wetlands

11. Begin to plant the various aquatic plants recommended.

Plant Recommendations


Sea Hibiscus (Hibiscus tiliaceus)–back-mangrove tree but can also grow in freshwater, in water-logged substrate, on land

Paperbark Tea Tree (Melaleuca cajuputi)—source of medicinal oil, pollinator plant

Sago Palm (Metroxylon sagu)—source of edible starch, pollinator plant

Attap/Nipah Palm (Nypa fruticans)—edible fruit and flower sap, source of thatch and soft wood, pollinitor

Nibong Palm (Oncosperma tigillarium)—has hard water-rot proof wood, pollinator plant


Dillenia suffruticosa—large swamp shrub or small tree, leaves used to wrap food.

Fragrant Pandan (Pandanus amaryllifolius)—aromatic herb. Many spp are swamp or coastal plants.

Vietnamese Mint/ Laksa leaf (Persicaria hydropiper)—edible herb

Pickerel Weed (Pontederia cordata) – pig food, coarse veg, aerator

Mangrove Fern (Acrostichum aureum)-can also grow in freshwater

Water Lily (Nymphaea spp. and varieties)—good at sucking up excessive nutrients

Buffalo Grass/ Mauritius Grass/ Para Grass (Brachiara mutica)—fodder grass

Horned Fern (Ceratopteris thalictroides)—edible leaves

Pond Weed (Monochoria spp.) – good greywater fliterer

Canna (Canna spp. and varieties)—has colourful flowers, good greywater fliterer

Golden Candlesticks/ Candle Bush (Senna alata/ Cassia alata)—ringworm medicine plant

Water Canna (Thalia geniculata, T. dealbata) — good greywater fliterer

Aquatic Pennywort (Hydrocotyle sibthorpiodes)— eaten as medicinal/elixir herb

Aquatic Ginger (Alpinia aquatica) — good greywater fliterer

Donax spp.– good greywater fliterer

Umbrella Plant (Cyperus alternifolius) — good greywater fliterer

Papyrus/ Egyptian Paper Plant (Cyperus papyrus)

Amazon Sword Plant (Echinodorus spp.)

Water Hyacinth (Eichhornia crassipes)

Cattail/ Cat’s Tail/ Bulrush (Typha angustifolia)

Elephant’s Ears Yam/ Wild Yam (Alocasia macrorrhizos)

Money Plant (Epipremnum aureum)

Yellow Burhead (Limnocharis flava)—edible spinach substitute, fodder plant

Taro/ Edible Yam (Colocasia esculenta)

Arrowhead/ Swamp Potato/ Chinese Potato (Sagittaria sagittifolia) -slightly sweet starchy edible tuber

Chinese Water Chestnut (Eleocharis dulcis) -sweet edible corm.

Water Cress (Rorippa nasturtium-aquaticum/ Nasturtium officinale) -leafy vegetable

Lotus (Nelumbo nucifera) -edible starchy rhizomes, leaves, flowers, buds and seeds.

Requires rich mud substrate.

Water Bamboo/ Wild Rice (Zizania latifolia) -Sedge-like plant. Edible part is the swollen base of the stem. This swelling develops when the plant is attacked by the fungus Ustilago esculenta which excretes a hormone which causes the swelling.

Water Clover/ Water Shamrock/ Nardoo (Marsilea spp.) - Sporocarps of Nardoo (M. drummondii) are edible BUT causes malnutrition and Beri-beri when NOT properly prepared for consumption

FLOATERS (may also grow in wet substrate)

Aquatic Sensitive Plant (Neptunia oleracea)—edible young stems

Duckweed (Lemna perpusilla)

Mosquito Fern (Azolla caroliniana)—has symbiotic nitro-fixing alga Anabaena azollae.

Water Lettuce (Pistia stratiotes) — pig fodder plant

Water Banana (Ludwigia adscendens)

Kangkong/ Water Spinach (Ipomoea aquatica)

Water Caltrop/Water Chestnut (Trapa bicornis/ T. natans/ T.bispinosa) - starchy 2 or 4-horned fruit, edible only if cooked, TOXIC if not.


-Many are invasive, noxious weedy spp. Plant, utilise and dispose with consideration and caution!

-These species are tropical to sub-tropical plants. Several are temperate spp able to grow in tropics.

-Most of these plants have flowers which attract pollinators.

-Most floating spp can also grow as emergent in a wet substrate.

-Some like Lotus may only be able to grow in deep rich muddy silt, and not a sandier substrate.

You are also welcome to grow Sugarcane there again on the chinapas since it seems to be doing good there. I noticed the soil was really rich there to from the years of composting in that area. Nice! Using a Bobcat (small one man tractor) to dredge out the site and compact down the earth will make work much easier and efficient. You could also use it for the rest of the project design. Rental for one or two days with an experienced person is highly recommend for best results.  Cow manure and pure clay can also be used as an alternative sealer for the wetland project.

The Fruit/Medicinal Vine Trellis Path

Creating a functional pathway that enables people to easily move through the property while keeping out of the sun and experiencing the wide array of vine like medicinal, local and edible plants along with shrubs, perennial herbs and ground covers that dot the sides of the path can be a really nice green experience. Imagine walking through a dense tunnel of plants giving you an up close and personal feel of Green Circle while keeping your feet dry and staying out of the hot sun. And then to come out of the Tunnel to a learning station filled with wonderful things to see and to experience.  This will also give the workers and yourself an opportunity to get out of the sun and rain while they keep close eye on the health of the plants and harvesting.


The Drawings show a flow for the pathway that is not a straight line. There are no straight lines in nature and so I tend to want to create paths that flow freely. The specific flow can be created with feng shui in mind. You could bring someone in that knows about feng shui or use your intuition to get a feel for what is most natural and create the direction of the path so that it meets up with the future learning stations that you have in mind. Paths can also double as a berm and contour the land for slowing drainage issues on property.

Paths can be mounded with ditches along the sides. There will then be an additional mound next to the ditch that follows the pathway. This will be your planting mound as well as the area that you can place the trellis poles. It will look like you have raised beds following the pathway. Pathway mound should round off for complete drainage and can be either mulched or kept maintained. Create the mound at least 4 inches higher then the height you wish to finish with since the mound will shrink due to compaction of the pathway. (ex. – if you want a mound that is 8inches please make a 12 inch mound). Pathways can also be strengthened with bricks, rubble or urbanite (material waste from construction sites) under dirt.

Food Forest Rain Drop Island Design

 Since most tropical trees have a shallow root system, islands (with a height of 5 feet [3 feet if trees are kept short for easy picking]) can be created with the proper drainage techniques discussed below. It would be very unlikely that water logging or root problems occur should these changes be implemented. (source:

I chose to go with an Island shaped as a raindrop.  The raindrop island design represents the desire to work with rather then against nature. The raindrop island that faces up the slope invites rain to slow down in time of need. And the other raindrop facing down allows for rain to flow without much resistance. This icon represents the desire to do what we can to harness the abundant conditions we have to our avail and to let go and allow what we cannot change to flow through without struggle.  This also enables a natural flow current that reduces erosion and creates a slight ‘flow form’ movement to the water when they meet at the drops pointed end. And with the implementation of diversion channels, water can be moved along the landscape slower or faster.

The top 8-10″ of soil, where plants’ roots thrive in the tropics, determines the success of your growing efforts. Plants need oxygen just as people do. Clay soil can be too compact to allow roots to “breathe.”

Adding organic soil amendments to the soil lightens soil texture, discourages compaction, adds nutrients, improves drainage and aeration, moderates soil temperature, and provides pore space, which is essential to plant growth. Suggestion: only work amendments into the clay soil when it is dryer.


What trees to use:

I have contacted a few growers with over 10 years experience growing organically here and in the tropics about what trees to use and told them all about the conditions of the soil, weather and land dynamics here (water logging). I also did my own personal research reading and seeing all the various places locally and in the city. If there were to be relatively little or no earthworks for redeveloping the land, I would recommend only the plants that were recommended to me below. Here is what they wrote:

Dear Marcus,

My ex colleague forwarded your email to me. I have just retired and have been working on organic farming the past 10 years.

Regarding your question :

I would like to suggest these plants:

1. Moringa otherwise known as the drumstick tree – can be grown from cuttings or seeds. The fruits are eaten in curries and the leaves are a good source of vitamin E. Since it is a leguminous plant, the leaves can be used also for green manure or feed for worms.

2. Sesbania – can be grown from cuttings or seeds. The leaves are a good source of iron and eaten mostly by the Malays and Indians. A good source of green manure.

3. The mangosteen tree is a good fruit tree to plant, but the gestation period for it to fruit takes 8-10 years. easy to maintain, once the tree canopy covers the ground

4. For the short term perrenials – the papaya is also reccommended – use the sekaki variety which is quite resistant to viral disease.

5. I guess fruit trees like rambutan, cempedak, nangka are easy to establish.

6. Since phosphate is required for the fruit trees to bear fruits, I would like to recommend using mycorrhiza (VAM) at time of establishment.

7. I hope there are no monkeys in your area – they are the biggest pests at time of establishment of the trees.

8. Other plants that can be considered are herbs such as misai kuching, noni (mengkudu) and indian basil .

Sorry for not including the scientific names as my references are still in my forwarding boxes.

Good luck

Yours sincerely,

Aini Zakaria

Re. trees: practically all the species listed in my book will do well there. Most people just want regular stuff, and that’s usually also what is available in the local nurseries. Most bamboos would work well there, it all depends on their purpose. If it’s not a large farm, it may be best to work with smaller species like B. multiplex, B. textilis, etc.

Not too many fruit trees like waterlogged areas, but most Garcinias (like Mangosteen) are ok with it, and also most Nepheliums (Like Rambutan).

I hope your travels turn out to be good ones.



If recommended earth works was to take place here, you should have good success with just about any fruiting tree that does well in the climate of Singapore! Three trees can be planted on the island in the golden triangle layout (1 to1.6 ratio found everywhere in nature) with a nice heavy ground cover and surrounded by nitrogen fixers and dynamic accumulators and the remaining layers of a food forest.

Another Term for ground cover is living mulch. It is common to seed tree crops with living mulches such as legume covers.  In Mexico, legumes used traditionally as living mulches were tested as nematode and weed suppressors. The mulches included velvetbean (Mucuna pruriens), jackbean (Canavalia ensiformis), jumbiebean (Leucaena leucocephala) and wild tamarindo (Lysiloma latisiliquum).

Other Living mulches used in Singapore

vigorous tropical ground covers here include:

–The wild native pepper creeper locally called Daun kadok (Piper sarmentosum), also used as a herb, med and veg.

Its a vigorous adaptable grower needing little maintenance, in sun or shade. Easy to source, available in nurseries or just gather from un-used land.

-kang kong and sweet potato, as u have seen for yourself already, forming huge mats of leaves and vines.

Mulch mats like Palm Fiber can also be used to wrap around the trees root area to maintain breathability and avoid weed growth.  I recommend at least a 1 meter or tree drip line radius of Palm fiber surrounding the Tree. I saw the palm fiber at the sustainable living Kampong at bottle tree park. You can find some there.

Earthworks for well drained islands

  1. Level the entire surface area with a bobcat tractor to create a 1 – 3% slope towards the drain by the car port.
  2. Move additional soil up the slope for later use to create the islands
  3. Lay a 4-inch layer of gravel across the base were the islands will be located. Gravel will not compact or decompose, so the island will not sink over time. Level off the gravel layer with a rake, distributing the gravel evenly.
  4. Measure the required length and width of chicken wire or netting for the island. Cut the wire with wire cutters to fit. Lay the chicken wire /netting over top of the gravel. This will keep any material on top of the wire from settling into the gravel, while allowing drainage.
  5. Place the soil layers over the chicken wire/netting creating a mound roughly 5 feet high/8-10 feet across, 15-18 feet long at drops end.
  6. Make sure the mounded island have a slope of 1:4 (33% or less) to the drainage areas.
  7. Build a berm across the top of the slop by the open shelter to allow additional water to flow into the wetlands and not where the islands are.

Land drains can be installed to channel water away from sections that surround the islands. This may provide the best practical solution in regions with an elevated water table or those prone to periodic flooding.


Diversion mounds as you will see in Drawings can be created to regulate the speed and direction of water flow.

Drainage and Soil amendments

The most important consideration before adding any amendments to clay soil is internal drainage. If the subsoil does not drain well, drain tiles may need to be installed. Surface drainage is also very important. Consider the land drains mentioned above if that’s an issue. Another essential step in amending clay soils is thoroughly (uniformly) mixing the amendments with the existing soil to a depth of about 12 inches or more. If amendments are not thoroughly mixed with the clay, layering in the soil could occur and interfere with water movement in the soil.

Clay soil that seals the surface in light rains are often sodium rich and melt in the rain. (source: Permaculture Designers Manual pg 209)

Based on Mineral deficiency analysis on page 210 section ‘L’ of the PDM, you may have sodium excess and or chlorine excess (if city water is being used at times) on your property. You will find on page 211 section {11,12} some perfect suggestions on what to do.

Other solutions (You are welcome to use any or all of these options):

  • Make low banks across run-off. (If gradients are too low, banks lined with crops may overtop or there may be excessive pond-age in the bank following run-off. I noticed this and following the guidelines on this pdf can remedy it –
  • Gypsum can be used when adding the organic matter for salt removal in soil.  The calcium in gypsum displaces salt in the soil. The salt then reacts with sulfate to form sodium sulfate, which is highly water soluble and easily leaches away. Removing the salt from the soil helps to aggregate soil particles, which eventually restores the soil structure. Salt can build up in the soil overtime with the use of compost, manure, seaweeds, urine, etc. Gypsum is a safe and easy-to-use soil conditioner. It gradually opens up the soil, promoting good drainage and aeration. It neither raises nor lowers the pH and is non-burning. The most ideal type can be found here:
  • The more commonly used organic materials are compost, composted animal manure, peat moss, cocopete and perlite. They can be used alone or in combination. Occasionally, coarse sand (0.25 to 1.0 mm in diameter) is added with compost to heavy clay soil. This is more commonly done during soil preparation for heavy traffic turf areas rather than perennial beds. A note of caution about attempting to improve clay soils by amending them with sand: When adding sand (often incorporated as much as 50:50 by volume) make sure it is a very sharp (coarse) sand. Otherwise, additions of sand to clay soil can create a cement-like structure that resists root growth and impedes the flow of air and water.
  • In some areas, you can find finely ground nuggets sold as “pine bark mulch.” These are an excellent soil amendment for clay, best when used as straight pine bark without soil mixed in.
  • Another choice to improve drainage is pea gravel, about 3/8 inch in diameter; non-organic, it won’t break down.
  • You can also add purchase top soil as an amendment for clay, but only if you mix it deeply into the soil.
  • Adding Earth worms to soil –worms can enhance soil aeration, fertility and productivity to all plant life.

Once the earth works, soil amendments and drainage pathways have been installed, your success rate at growing your food forest will be exceptionally high.

List of fruits that can possibly grow here can be found at this site: (Most can be found growing here in Singapore and are doing well)

I also highly recommend looking up some methods to properly plant and care for your new fruit trees in the Permaculture Designers Manual or the Organic Gardening Encyclopedia books that you have. This can make or break the productivity and health of your trees.

Food Forest Nursery Design

As you know many Trees can be kept small (say 2 to 4 meters) in large pots and create very good fruit production with the proper soil and watering techniques. I propose using your outdoor covered area with say 8 or 10 large trees and 20 or so small trees which can be easily managed with good success. It can also be an Urban Gardening learning Station

How to Manage fruit trees in Pots.


Dwarf fruit trees from Australia can be ordered here:

Not all are suitable for this climate but many are!

Other Recommendations

There are so many other recommendations I could suggest. Such as using the flow form with the rain barrels over in the tall open shed to create liquid fertilizers. Moving your composting to the North/northwest corner of your property to enhance the banana growth there while getting compost out of the wind path towards building and walkways. Maybe also starting a large vermaculture system under that covered area as well and Installing a Drip irrigation system in the pots. We could discuss what tree goes on what Island to create the food forest; how to implement other stations on the property and much more details can be assessed.  More time would need to be allocated to create this within the design.

I am honored to have been of service and look forward to see your place as the design is implemented.


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