What is square foot gardening (SFG)?
American Mel Bartholomew is the ‘founder’ of Square Foot Gardening – a concept that he launched in 1981. SFG is an intensive, shallow, raised bed system using a mixture high in nutrients and organic matter to support vigorous growth in a small area. A system doesn’t take up much space, and watering can be efficient and overall water use reduced – another benefit. The ideal SFG is a square bed 4ft x 4ft (1.2m x 1.2m) divided up into a grid with 16 smaller squares within, or a Square Metre Garden (1m x 1m) divided up into 9 smaller squares. The concept is to devote one ‘square’ to a particular type of plant. How many plants you put into that ‘square’ depends on the ultimate size of the plant. Larger plants (ie. Tomato, basil) you would only plant one in the centre of a square. Smaller plants, (ie. Strawberry, lettuce) – 4 per square. Even smaller plants (ie. Spinach) maybe 9 per square, and smaller again (ie. Radish, onion) maybe 16 per square.
Mulching: what is it and why is it important?
Mulching is a method to cover the soil while growing the crop. Mulching material can be inorganic (polythene sheet, pebbles) or organic like straw, wood chips/shavings, layer of shredded dried leaves or similar material. Mulching is done to protect the soil from erosion, weed infestation, to retain soil moisture, reduce evaporation and to help regulate soil temperature – either protecting it from scorching heat or from frost in colder parts of the world. Mulching is one of the techniques that help to get maximum yield per surface. It is incredibly beneficial for improving soil biota and hence increasing soil fertility. Organic mulch will eventually decompose and add a much needed organic matter to the soil.
How to mulch?
Make any necessary amendments to the soil before applying the mulch. That way you will not have to dig up or move the mulch to add elements to the soil.
Remove any existing weeds from the area to be mulched. Hand-pull the weeds or dig up weeds with large root systems.
Spread a 6- to 8-inch layer of mulch on top of the planting area. If your choice of mulch are wood chips or wood shavings, we suggest you spread a 2 cm layer of manure compost before applying mulch. This will ensure that the plants will not suffer from temporary nitrogen depletion which can happen when using woody material as a mulch. If you decide to not supplement with nitrogen rich material, plants might have temporary nitrogen deficiency which will correct itself once the part of woody material in touch with the soil will decompose. If using rice straw mulch you can skip the step of adding that extra nitrogen rich material on the surface of the planting area. If you mulch a planted area, keep the mulch 10 to 20 cm from the stems or trunks of plants and trees. When mulching trees and shrubs, spread the mulch out far enough from the base of the plant that it will cover the entire root system.
If your area is very windy and it blows away a lightweight mulch layer, you can add a top layer of wood mulch to keep the lighter mulch in place. Or you can mulch with only heavier mulch material.
At the end of the planting season you can either till the half decomposed mulch (rice straw, shredded leaves and similar organic matter) into the soil together with other necessary amendments. or better yet just add another layer of amendments and mulch on top of the last season’s mulch.
Does mulch attract termites?
Soil life and insects like and thrive in moist environments. This is one of the benefits of using mulch – to protect and enhance life that is essential for soil’s fertility. However – bugs normally don’t thrive in mulch. They typically preexist in deep ground where the environment is moist and will move to shallower areas if the surface is protected by mulch. So while the termites might not actually feed on the mulch, the presence of it certainly can provide better conditions for a termite colony to start, or continue to develop. A better way to look at the attraction issue would be to conclude that mulch increases a termite’s ability to survive around your home if they are already present.
We have been using straw mulch in our garden since some time now and haven’t found termites to be of any issue. It is likely though they will find any type of wood mulch appetizing. Termites are (as well as fungi) essential for the natural recycling of cellulose and lignin rich materials. By decomposing woody material they are in fact enriching the soil. We suggest you don’t use wood mulch in your wooden or bamboo garden beds. As a preventive measure against termite infestation, we also suggest avoiding using woody mulch (either on top of garden beds or as on the paths) in the vicinity of any buildings.
Why is the soil depth of a garden bed important?
Different plants have root systems of different depth. In order to give your plants best conditions for their healthy growth, the depth of the well amended fertile soil needs to correspond to the plant’s root depth. Most herbs are not very demanding in terms of soil quality. Many of them however are sensitive to waterlogging here in tropics where high content of clay in the soil prevents good drainage and root aeration. When it comes to vegetable gardening, you always want the best soil you can get and consider plant needs when deciding how tall your raised garden bed should be. Salads, mustard greens, collards and brassicas are easy to grow in shallow raised beds (around 15 cm). Beans, cucumbers, eggplants and all root vegetables will thrive in around 30 cm tall raised beds. Tomato plants and most squashes will generally need an even taller raised bed except if the native soil below the raised bed is of decent quality and most importantly with good drainage properties. When deciding about dimensions of your raised beds, plan in advance to avoid a failed harvest. Our terraced beds are a great solution if you wish to grow vegetables within one garden bed with different depth needs.
What is the best orientation of garden beds in the southern hemisphere?
We suggest beds run roughly in a N-S direction. This allows for the most sun exposure and reduces the shading amongst plants. Make sure the tallest plants are at the south end in order to not shade out shorter plants. In tropics sun can be pretty harsh and some suggest to plant the tallest plants (like corn and okra for example) along the central line of the raised bed followed by medium height plants like peppers or eggplants on either side and finally by shortest veggies like radishes or carrots along the edges. The best is you observe the movement of the sun and shades in your own yard to determine what would be the best placement of your garden beds and plants within.
How much sun do plants need?
At least 4 to 5 hours of direct sun exposure is recommended for most fruits and vegetables. More is better, especially for fruit producing plants. There are herbs and leafy vegetable plants that will either tolerate or even demand less sun. For many fruiting plants, however, for a good harvest the sun is as important as the quality of the soil.
Why should I start composting?
One of the most concrete and simple ways that we can do to help regenerate the soil and divert organic waste from landfills, is to compost them. Composting at home might sound intimidating or bothersome for some people, but in reality it’s really not that complicated. Not only does composting reduce pressure on landfills, more importantly it is preventing the loss of valuable nutrients that would otherwise be lost under the pile of other inorganic trash. By home composting of garden and kitchen waste, you are saving twice- firstly the volume of your garbage bin is reserved for other waste that you don’t have any use of, and secondly making your own compost means you don’t need to buy any! Throwing kitchen waste into the regular trash bin is probably producing a foul smell by the time the pick-up service comes around. With proper composting technique there should be no bad smells around the compost pile.
Where should I position my garden beds?
Look for an area in your garden that is relatively flat and ideally receives at least 6h of sun per day. Up to min 4h a day is ok for most plants but it will delay the harvest time and the produce might not be as bountiful. Some midday shade is fine, in fact even desirable in this tropical heat. Also avoid low lying areas where rain water collects.