Ninety-eight percent of all climate scientists agree that global warming – predominantly caused by human activity, from the burning of fossil fuels to the intensive farming of livestock and the pollution of the world’s oceans – is a fact. (The remaining two percent, by the way, are almost all scientists whose research has been funded at least in part by fossil fuel companies.) Besides rising sea levels and increased incidences of extreme weather events like hurricanes and tsunamis, one of the primary effects global warming has on the planet is longer and more intense periods of drought. Indeed, recent years have seen record droughts in many parts of the world. For example, in 2014, four Central American countries – Nicaragua, El Salvador, Honduras and Guatemala – experienced their worst drought on record, causing more than half a million families to face hunger from failing crops and livestock losses. The same year, the state of Queensland in Australia experienced its largest recorded drought, with approximately 80 percent of the area of the state affected. While much of the United States saw drought conditions for successive summers from 2010, with many locations experiencing, in 2013, their driest year for over 130 years.
If you live in a location that experiences drought, you will know the effect that it can have on your permaculture plot. But it seems likely, unless there is a much more concentrated effort to curb greenhouse gas emissions, that more and more people will experience drought in the future. Here are some things you can do to help limit the impact drought condition can have on your site.
The best strategy for preparing your site to withstand the rigors of a period of drought is to start preparing for it early. Making sure that you have a good soil structure is a key part of such preparation. You want to aim for a good balance of clay and sand so that you have a loamy soil. Not only will this be the ideal growing medium for most plants, ensuring that they are strong before the drought conditions arrive, but will help preserve what moisture does go on the soil. If the soil is too sandy, any moisture will percolate through the soil too quickly to be useful to plants. You might think that having heavier, clay soils would be a good idea, considering that clay holds moisture more readily than sandy soil. However, in drought conditions, clay soils harden, making moisture percolation much more difficult. Treating your soil with lots of organic compost will give plants the nutrients they need and promote microorganism activity that will help maintain a good structure. A good soil structure will encourage plants to send roots down deeply into the soil profile, searching for water, making them better able to withstand times when moisture is scarce.
Instituting a rainwater harvesting system is another important preparatory step you can take before drought conditions arrive. Arguably, capturing rainwater runoff is something all permaculture gardeners should do if possible, as it preserves a resource that is precious, finite and all too often wasted. However, in drought-afflicted areas, it is even more important. Simply placing a water barrel at the base of your guttering downspout can capture gallons of water that could be crucial to your plants’ survival in the hottest times of the year. When designing your plot, make water preservation and capture a prime design influence. Perhaps it would mean digging swales on downhill slopes to collect runoff from the land, or adding an underground rainwater-harvesting tank that is fed by diverting pipework from all buildings on the site. Whatever is feasible in this regard in your permaculture garden, capturing and reusing rainwater can be key to protecting your plants from the worst of the drought.
Mulching is an important strategy for all permaculture gardeners, but especially for those in drought-affected fallen-leaves-65544_640regions. A good layer of organic mulch – be it straw, wood chips, fallen leaves or newspaper – can make a big difference to plants when temperatures are high. Indeed, mulch can keep the soil as much as 15 degrees cooler that the air temperature when the thermometer soars. Mulch also slows evaporation of moisture from the soil, leaving more in the soil profile for the plants to access, and helps keep roots cool so they are more effective at absorbing available moisture and nutrients.
Look to your plants to guide you about watering them during the drought period. During such times, water becomes an even more precious resource, and your local authorities may even place water restrictions on inhabitants. As such, you don’t want to be wasting water. Well-established trees and shrubs, for instance, can usually survive several weeks without water, whereas you perennials and annuals require moisture more often. When you do water, water heavily once a week or so, adding around an inch of water to the garden beds. In drought conditions, a sparse sprinkling, even if done every day, will simply evaporate from the surface of the soil before it has had a chance to sink into the soil where the plant roots can access it. Slow watering will also help the water penetrate the soil. You may also want to consider drip irrigation systems for your most vulnerable plants. These will allow the water to be directed at the roots where it is needed most, and avoid moisture sitting on the surface where it can evaporate. Water early in the morning or later in the evening to allow the maximum amount of water to penetrate the soil.
When deigning your permaculture plot, the use of native plants that are adapted to the soil and climate in your area is an effective strategy for ensuring your plants survive whatever weather conditions your plot experiences. Once technique to enhance this is to sow seeds directly into the garden for cultivation, rather than raising seedlings in a protected environment. Planting seeds outside helps the plants acclimatize to their environment as they germinate, and means they are likely to be able to withstand a relative lack of moisture for longer – even if just a day or two longer – than plants that were first raised in the controlled, modified atmosphere of a greenhouse or inside the house, before being transplanted to the garden.