For months the phenomenon of El Niño has begun to affect areas of California and the west coast of the United States. It will last until 2016 and is already hitting areas all over the world, producing everything from torrential rains to long droughts, which are taking their toll on crops and farmers. Nevertheless, cannabis is strong and, although it needs a great deal of care, endures water scarcity and various climate changes quite well. Here we explain how droughts affect our outdoor cannabis plants.
The water shortage means that soil humidity drops, the ground hardens, cracks and becomes less permeable to liquid. Thus, when rain finally does fall, no matter how strong it may be, it is not absorbed efficiently, and water escapes in large quantities, with plants unable to benefit, damaging outdoor crops and triggering flooding.
Marijuana plants need enough water to grow sturdy, especially from mid-summer until the fall. On a hot day a large marijuana plant may require up to 60 litres of water, almost double what other crops would need. Therefore, a 10-day period without water does great damage to the crop.
The lack of rainfall affects the water table; that is, the accumulation of groundwater located very close to the surface that helps to nourish plants. When there are limited resources, only those with deep roots can reach down to lower levels to get the water they need.
Under these conditions marijuana growers have to resign themselves to the situation and greatly reduce the resources they apply to their crops. This affects the quality of their plants and their development, as they are sensitive to moisture and soil conditions.
Also, excessively dry conditions spawn pests, which one has to invest large sums to avert with specific products. However, THC is a natural pest repellent and, according to research, the plant produces even more of it when it is under stress, facing drought, or sick, enabling it to fend off external threats.
Cultivation in valleys is widely recommended, as they provide for abundant natural irrigation. One might also take advantage of other options, such as sprinklers and misting or drip systems, while avoiding the use of hoses. To reduce evaporation burying the pots is recommended, so that their sides are not exposed to sunlight.
Growers are also encouraged to use instruments to collect rainwater and store water from rivers and streams when they are running high (winter and spring) to draw upon during the rest of the year. Unfortunately, such systems can be very expensive. For example, the drought this year in California is driving up the cost of water, while farmers are struggling to raise the price of their products.
Another recommendation to cope with periods of drought is selecting genetics that are grown outside, and choosing those indigenous to the driest areas. Keep in mind, for example, that Indica varieties have large leaves, resulting in greater moisture evaporation. Sativa plants, therefore, are preferable.
In addition, Indica plants often produce dense, compact buds that are more sensitive to heat, which can lead to mildew. If you have no choice but to cultivate these varieties, you'll have to prune them to obtain smaller buds and mitigate this threat. Farmers should also use other strategies, like adding polymers to their substrate to improve its water retention capacity, or placing straw on the surface to limit evaporation (though, if your fields are extensive, this will be another added expense).
It is also advisable to do everything possible to protect your plants’ reticular systems. One option is to grow in clear pots and cover them with white canvasses to prevent heat build-up. Another option is to grow in areas that get plenty of shade. The plants’ flowering will be less productive than under direct exposure to sunlight, but water consumption will be reduced, which is our aim.
Despite these drawbacks, marijuana plants can adapt to dry places and adverse conditions due to their genes' special capacities, which enable them to do quite well under drought conditions. Specifically, they can fight against situations of environmental stress, low temperatures, high salinity, and water shortages. Some of their genes activate the production of proteins under adverse conditions, allowing the plants' cells to continue to perform their vital functions at any time.
Although cannabis usually adapts to the amount of water it receives, irrigation should be carefully controlled because if plants receive lots of water they will grow strong, but they'll need the same amount of water throughout the growth phase. If a plant gets big and its water supply is abruptly curtailed, most of its leaves will die. However, it is during this growth stage when grass best withstands droughts.
If a plant continuously demands water it will be necessary to increase irrigation to ensure good growth, and this will not be possible when one has to comply with water restrictions in each area. A lack of water will be very damaging during the flowering phase, when the most is needed. Conversely, when marijuana is exposed to an intense and sudden amount of water (during, for example, heavy rains), soil oxygenation is very low, and the cannabis's growth will be severely affected.
Experts say climate change is making marijuana stronger and able to withstand water shortages better than other plants. Although marijuana often requires large amounts of water to really thrive, it does not need much to survive. This is one of the plants that best adjusts to almost any climate, which explains why it has survived for millions of years. That is, although its quality is affected by adverse elements, it is so strong that it always emerges victorious.