Nitrogen (N) is an essential element for healthy plants, especially during vegetative growth, and very early bloom, when they require it the most to give them the building blocks to produce bountiful fruits and flowers.
Generally speaking, Grow Base Nutrients, like Shogun Fertilisers Samurai range, contain enough nitrogen for the early to mid stages of a plants life, but nitrogen deficiency is also a common problem, especially when growing in soil, or with novice growers who are worried about giving the plants ‘too much too early’. Growing in hydroponics, and to a degree coco, isn’t as susceptible to nitrogen deficiency as soil, but it is something the grower should be aware of and know how to correct.
The first signs of nitrogen deficiency are yellowing of the leaves, although it’s not to be confused with magnesium deficiency as both show similar traits, albeit the latter is more between the veins rather than over the entire leaf. If the problem persists, plants will go on to display stunted growth, leaves will become completely pale, then eventually die and fall to the ground, while harvest quality and yields will be well below their optimum.
The yellowing usually starts around the lower set of leaves and will slowly spread throughout the entire plant if left untreated. The yellowing occurs as the freely available nitrogen from the fertiliser is used up, the plant then has to rely on its own resources by breaking down any stored nitrogen in older growth. This newly broken down nitrogen is then transported to new growth where it’s needed the most, but this also means that overall, there’s a shortfall in the amount of nitrogen required for the entire plant to continue growing strong and healthy.
The simplest way to treat nitrogen deficiency is to increase the dosage of the Grow fertiliser. The feed chart might state that the plant should be getting 3ml per litre of water, this however is only a guide, different plants, strains and growing methods may need more, or sometimes less. Start by increasing the Grow feed by increments of 1ml per litre until a level is found that the plants are happy with and leaves become a lush green colour again. A rule of thumb is to not panic and dramatically increase the Grow feed, for example doubling or even tripling the recommended dosage to 6ml or even 9ml per litre. It’s much easier to add more nitrogen if needed, than take it out if the plants are overfed as this could involve a complete flush. Alternatively, if nitrogen levels are very low, a supplement like House & Garden N 27% Nitrogen or Canna Mono Nitrogen can be used with the nutrient solution to give the plants a boost of nitrogen.
The second method is to use a foliar spray. Again House & Garden N 27% Nitrogen or Canna Mono Nitrogen can both be used in this way, but if using as a foliar, DO NOT also add it to the nutrient solution, use one method or the other. The advantage of applying as a foliar is the stomata will take on the additional nitrogen quicker, allowing it to be transported around the plant up to 10 times more efficiently than when being absorbed by the root system. This is a particularly important method if the plant is suffering from nutrient lockout (roots not absorbing available food) due to outside influences, for example low grow room temperatures. No matter how much nitrogen rich fertiliser is given to the plant, the deficiency will not go away. By using a foliar spray it’s a more direct way of giving the plant what it desperately needs and, bearing in mind the source of the problem is corrected, improvements will be seen quicker.
The vegetative growth cycle can be often overlooked by some growers who are desperate to get their plants into flower, but it’s just as important as the final few weeks of bloom. Get your nitrogen levels right at the early stage, your plants will then be healthy, strong and have the framework to produce overwhelming fruits and flowers during bloom.
So there you have it, a quick overview on why nitrogen is important, as well as how to spot, and treat a deficiency when it occurs.