Should you add mulch to your vegetable garden? There is no straightforward answer, as every farmer or gardener has their subjective take on the issue. Mulching has its fair share of pros and cons. You have to weigh on these benefits and risks to ascertain if you should add mulch to your vegetable garden. If the benefits outweigh the risks, and if a certain kind of mulch is suitable for a particular type of vegetable crop, then by all means you should decide in favor. If the ill effects and cost of mulching do not seem reasonable or pragmatic, then you must consider alternatives.
Benefits of Adding Mulch to your Vegetable Garden
Mulching retains moisture in the soil. Most types of mulches will prevent or limit evaporation, especially in subtropics and tropics. Evaporation does not only affect the topsoil. It also affects the moisture in the subsoil. Hence, mulches can conserve soil moisture, and also avert erosion. Mulch can also reduce soil compaction and enhance permeability.
Mulch is effective at regulating the temperature of the soil. Most types of mulches can retain heat, and thus keep the soil warm. Interestingly, mulches can also keep the soil cooler than it would be otherwise. Since mulches tend to absorb some heat when exposed to sunlight during the daytime, the soil is spared the scorching rays and remains a tad cooler. Depending on the type of mulch you choose, it can prevent freezing and frosting in the soil, and also keep the temperature down during summers.
One of the primary reasons why many farmers and gardeners use mulch is its effect on weed. Mulching prevents rampant growth of weed. Most farmers and gardeners simply do not want to deal with excess weed. It is a tedious task. Anyone who has been hit by a wild growth of weed knows how much it damages the crops and the quality of produce. Weed makes life difficult throughout the growing season, and at the time of harvest.
Mulching is useful in areas that receive heavy rainfall. Soil erosion is not as much of a concern in plains that are not particularly windy. The major threat in such regions is rain, especially torrential showers. Mulch can prevent soil erosion caused by rain. It also helps in retention of soil fertility, or the nutrients that are already there, which would otherwise be adversely affected by rainfall.
Another significant benefit of mulching is disease and pest control. However, this is a double edged sword. Organic mulches can keep insects and pests at bay. Some types of mulches, such as those including neem, can make it difficult for many types of pathogens to thrive in and around your vegetables. Mulching can also prevent midges, beetles and sawflies from invading your garden or farm.
Risks of Adding Mulch to your Vegetable Garden
Mulch can increase the temperature of the soil, especially in tropical regions. Since some heat is retained by the soil due to the mulch on top, the ground is unable to let go off that excess heat during the nighttime. The already warm soil gets heated again throughout the following day. Regions that are hot and humid pose a greater risk. Mulching can not only retain excess heat but also unnecessary moisture. This can lead to many problems, for several types of vegetable crops.
While mulch can prevent disease and serve as a method of pest control, it can also enable the breakout and spread of certain types of diseases while also facilitating the thriving of some pests. Warm and moist conditions are perfect for many pests and diseases. This is why gardeners and farmers are advised to use mulch that is relatively drier and not too effective at regulating temperature.
Inorganic mulch, especially polythene and the likes, is unhealthy for many types of vegetables. These create an anaerobic environment. The soil does not get sufficient oxygen, or air. This makes it difficult for the roots underground to thrive. Crops can effectively be destroyed if the mulching is inappropriate. Inorganic mulch can also create a rather artificial microenvironment. That would present a whole new set of challenges depending on the crop being grown.
Organic mulch, such as crop waste, also poses a few problems. There may be seeds of weeds and other unwanted plants mixed in the waste. These would spread to the garden or farm and subsequently lead to a wild growth of weeds and other unwarranted matter. Both inorganic and organic mulches can also prevent timely germination of seeds in arid regions, especially in the fall and during the dry season following a wet spell.
Mulch is not suitable for vegetables that do not grow very tall. If you have a garden or farm where multiple vegetables and grown alongside other plants, then those that tend to be tiny or short will be effectively suppressed and stunted by mulch. Dry mulch is also a fire hazard.
Types of Mulch used in Vegetable Gardens
A plethora of types of mulch is used in vegetable gardens around the world. These include corn cobs, fine bark shavings, leaf litter, pine needles, straw, compost, nut meat hulls, sawdust, chipped wood, and grass clippings. These are all organic mulch. Then there are inorganic mulches such as recycled rubber, glass, crushed rock and plastic. Each of these options and a combination of more than one has its strengths and weaknesses. You must also bear in mind the compatibility of the mulch and the vegetable you are growing.
In addition to all the preventive and retentive effects of mulching, there is one crucial benefit that should be taken into consideration while choosing the material, or materials. Organic mulch, and even a few inorganic or chemical ones, can add nutrients to the soil. Such mulches can boost growth and lead to a bumper harvest. This is why many gardeners go for shredded or chopped leaves instead of newspaper, straw instead of cardboard, compost instead of mats, grass clippings instead of plastic. You may also consider biodegradable mats, salt hay and rotted hay.