When planting tropical vegetables it needs to be kept in mind that they generally take up more space than the average temperate vegetable such as lettuce, beans and capsicum. Tropical vegetables are by nature perennial and they grow to a larger proportion in size and this means that they can overwhelm other plants in the garden and shade them out. It is therefore practical to give them a garden space of their own for that reason. As most tropical vegetables don’t need the same amount of irrigation as the temperate vegetables is another reason to separate them into different gardens.
Tropical vegetables come in all shapes and sizes and for the beginner it is difficult to realise their growth habits and therefore it will be a challenge to place them in an advantageous setting so that one can support another and not crowd another out. So how do we plant these vegetables to their best possible advantage?
A food forest garden!
A food forest garden can supply all the needs for tropical plants with very little watering needed. It is a support system that, as the name implies, supports one another in a natural setting.
Take a natural forest for example and feel the difference that surrounds outside and inside of it. Outside of the forest can be hot and uncomfortable whilst inside the forest it will be cooler and more pleasant. That is the effect of micro- climate. A food forest will also create its own micro- climate so that the plants that live within its perimeters won’t suffer the dehydration of being out in the full sun in extended dry periods.
In a natural forest, especially a rain forest, you will observe that there are many layers of growth. In amongst the tall trees are vines that meander from tree to tree, fallen down trees covered in moss creates habitat for wild life, leaf litter covers the ground and smaller plants grow wherever they find a bit of space. A forest is an eco system that is quite different than outside of it. A forest also supports a lot more life than outside of it. It is in fact a total support system as one plant often supports another to make this forest a possibility to exist.
A food forest simply mimics a natural forest.
Creating your own food forest garden is possibly the most challenging and rewarding gardening experience you will ever have. Can you imagine such a garden close to your house? Whenever you need a break from the busyness of daily life you can wander down and take a little stroll in your own food forest garden. I often do this with a cuppa and have a ten minute respite so I can drink in the atmosphere and relax a bit. It is also a great way to escape the house when there are too many people making noisy demands on you. I can quickly slip out without anyone knowing where I am! That’s my little secret so don’t tell anyone will you?
So how do you start a food forest garden from scratch?
How do you turn a lawn into a forest?
A lawn is a good starting point and is like starting with a clean slate. If your proposed site is in a paddock it would be a good idea to slash it first so that you can see the ground you are working with.
1. The first step is to find the best aspect for you food forest garden. The morning sun should flow onto the food forest garden and the harsh afternoon sun should be shaded out by trees that have narrow leaves so as to create lots of dappled sunlight. Avoid trees that have leaves that make large shade blocks as this will stifle the growth of your plants. All plants need adequate sunlight to thrive although some require less than others.
2. The second step is to decipher the slope of the land. You are going to aim at harvesting any run off from the rain that comes down the slope so that the plants can take advantage of that. The way to catch this runoff is by swaling.
- Find the contours of the slope with a dumpy level or an A frame.
- Mark out the level points of the slope with bamboo or star pickets.
- Dig out a shallow channel and place the soil from the channel on the downside of the slope, this is called the bund. The channel can be up to a metre wide.
- Plant your most important trees on the bund of the swales with inter-plantings of tropical vegetables and support species.
- You can have any amount of swales and generally the steeper the land, the more closer together they are. Very steep land however is not suitable for swaling as erosion problems can occur.
- When you have your swales in place it is best to sheet mulch the entire area. If the food forest garden is large then it can be done in stages but keep in mind that the earth works have created bare soil and this will quickly grow weeds if nothing is done. To prevent this from happening it will be a good idea to broadcast seed such as pigeon pea, cow pea or any other legume ground cover crop so as to cover the soil, fertilise it and help add organic matter into the soil. You can plant trees in your food forest area before you start sheet mulching, or even sheet mulch around existing trees.
Sheet mulching - What is sheet mulching?
- Sheet mulching is the no dig method of gardening and it is very successful if it is done properly. By soaking newspapers in water and laying them on the ground, you will create a smothering blanket that will keep the soil damp and kill off all the weeds and grass underneath. The newspapers will need to be covered with mulch hay so that the papers will stay damp and to stop them from blowing away in the wind. It’s as simple as that!
- It is important to generously overlap the wet newspapers and to have them thick enough to create that smothering blanket over the ground. Any gaps will allow the existing weeds to find a toe hold and continue to grow over the newspapers so it is important that the job be done properly. The following pointers will ensure a successful start to your new food forest garden.
- Collect newspapers well before you aim to start. Refuge stations can be a good source. In Cooroy we have requested for a bin to have people throw in their old newspapers and there are always several bins full of newspaper. Otherwise ask your neighbours to start saving their old papers for you! Using newspapers this way will directly recycle them back into the ground and this will also make you feel good.
- Wait until good rain has fallen so that the soil is wet to begin with. This will help to break down the weeds and soil underneath as it attracts the worms and other creatures.
- Soak the newspapers thoroughly for at least ½ hour before using them. You can use wheelbarrows, wheelie bins or anything that will hold water to soak the papers in.
- Use them in half newspaper thickness for larger areas (I just open them up) so that the weeds will be kept at bay for many months.
- Use a generous amount of straw in ‘biscuit’ form not fluffy mulching. You will see that the layers in a bale of mulch hay will come off in sections. Use mainly these biscuits as this will keep a secure covering for a long time.
- You can scatter blood and bone and any kind of manure down on the ground before laying down the newspapers. This will encourage the worms and microbes to break down the roots of the weeds and grass and also break open the hard soil underneath the sheet mulched area. You can also lay down lucerne mulch on top of the paper as long as that is covered well with mulch hay.
- If the soil was moist when laying down the newspapers, wait at least 3 weeks before planting as by then the weeds would be killed of. This is to ensure that when you plant and break open the newspaper underneath, you won’t have weeds growing through anymore. In the cooler time of the year you’ll need to wait a bit longer for the weeds to die.
- When wanting to plant straight away into the newly laid sheet mulched area you can do so by making a hollow in the mulch, use compost to fill the hollow and then plant into the compost. The newspaper needs to stay intact otherwise the weeds will eventually takeover. The disadvantage with this method is that the plants will need regular watering as it dries out very quickly. If the newspaper is laid very thick it will also take far too long for the roots to be able to penetrate into the soil so this needs to be kept in consideration.
Now you have your foundation for the new gardens. You are now ready for the fun part; designing your pathways and garden areas. You can use your imagination as to how to meander your pathways throughout your food forest garden but the lie of your land will probably dictate much of that. Your own knowledge of the land will determine where the deeper pockets of top soil are that are more conduisive to direct planting into the ground. Wet areas would be suitable for growing kang kong and taro whilst the cassava can be planted in the more open and dry positions as they like the full sun. The turmeric can be planted as an understory as well as the chillies so a potentially shady area can be used for these plants. Be sure not to plant too many fruit trees as the food forest is not an orchard. Fruit trees need adequate sunlight and airflow to be really productive. For every fruit tree there should be a dozen support species planted around them. Pigeon pea, crotolaria and popcorn cassia are excellent examples but so are the lemon grass and comfrey. These plants will become chop and drop material to mulch around these important trees and also around the other food crops.
If your soil is quite poor or even non- existent then you may want build up garden beds for the tropical vegetables so that there will be some soil depth and moisture retention for them to grow in. You can easily plant your support species outside the beds as these plants are hardy and will grow in challenging conditions. These plants will then provide a continuous source of mulch. Arrowroot, pigeon pea, lemon grass and comfrey are also excellent weed barrier plants so they maybe planted on the outside edge of the food forest garden to serve multiple functions. A classic weed barrier is an outer row of pigeon pea, then a row of arrowroot, then a row of lemon grass and an inner row of comfrey. Comfrey is the first plant you will pick for mulch for the garden then the lemon grass can be chopped and dropped over the comfrey leaves. The arrowroot is then chopped and dropped if they are not to clumsy and big for the garden, otherwise they can be thrown around the base of the fruit trees along with the pigeon pea.
So now you have sweet potato or some other ground cover establishing itself and the support species are in place to create mulch, weed barriers and shade and you will want to concentrate on growing your tropical food crops. The preparation or condition of your soil will determine how fast or how slow your plants are going to grow so a good foundation will certainly help with the final results. Compost, deep litter from the chook pen and manure are all good for the tropical vegetable beds before you plant. Finding the right spot for your tropical plants will determine the individual requirements of these vegetables. Try to find plants that group well together such as yams, New Guinea beans, chilacyote and yam beans can use trees to climb on while the shade from the trees and vines will create enough shade for the mushroom plant, Rungia Klosii. Open spots are great for cassava while taro and cocoyam can tolerate part shade. Remember that no plant likes it too shady as this will kill them off. Your support species are just that, don’t let them overtake your food forest by shading everything out. They need to be constantly chopped and dropped in the growing season so that they perform the job they are required to do; create organic matter and nutrient to the soil so that your food crops will benefit by the extra available nutrient and moisture.
Foot paths can be made by using crusher dust and packing it down on top of the sheet mulching. Depending on the soil and your local climate,
footpaths can be very nebulus as they keep disappearing under the sweet potato or pinto peanut! In a drier climate there will be easier control over your pathways as growth won’t be as rampant.
Add frog ponds wherever you can as the frogs will eat the pests. Baby baths and washing up bowls are excellent for this purpose. Plants such as Queen Ann’s lace, allyums, buckwheat and other small flowers will attract predator insects that will breed up on these small flowers. The predators are then bred up in numbers to make an impact on other insect pests. Nasturtiums are also beneficial in a food forest. Also design your system so that the chook house is uphill from the gardens so that the run off rains will flow the extra nutrients into the gardens where it is needed.
So whichever local climate you live in, you will be able to expand your garden horizons by implementing plants that support your food crops and therefore constantly improve your soil life. If you have living soil then your plants will be healthy and abundant. They will withstand longer dry periods with very little or no irrigation.